Karnataka 1st PUC Biology Question Bank Chapter 4 Animal Kingdom

1st PUC Biology Animal Kingdom One Marks Questions and Answers

Question 1.
What b intracellular digestion? Give an example.
Answer:
Digestion within the food vacuoles of a cell, is called intracellular digestion, eg. Amoeba, Paramaecium, Sycon, Ascon etc.

Question 2.
What is saprozoic nutrition?
Answer:
The process of organism feeding on dead and decaying animals is called saprozoic nutrition.

Question 3.
What are the the kinds of openings found on the body of a sponge?
Answer:
They are:
(a) dermal ostia and
(b) osculum.

1st PUC Biology Question Bank Chapter 4 Animal Kingdom

Question 4.
What are spicules?
Answer:
Spicules form the skeleton in sponges. They may be made up of calcium, silica or spongin protein.

Question 5.
What is a spongocoel?
Answer:
There is a large cavity inside the sponge body called spongocoel or paragastral cavity. It communicates with the outside through osculum.

Question 6.
What is a gemmuie?
Answer:
Internal buds in sponges are called gemstones which are capable of developing into individual sponges.

Question 7.
What is a hermaphrodite?
Answer:
An animal having both male, and female reproductive organs like testes and ovaries is called a hermaphrodite.
eg: Sponges, Hydra etc.

Question 8.
What is radial symmetry?
Answer:
Division of the body into equal halves along any vertical plane. In such an organism the various body parts are radially arranged.

Question 9.
What is polymorphism?
Answer:
A colony with many kinds of zooids having different functions is called polymorphism.

Question 10.
Why are coelenterates called diploblastic animals?
Answer:
The body of coelenterates have two cell layers with an outer ectoderm, and an inner endoderm.
Thus they are called diploblastic animals.

1st PUC Biology Question Bank Chapter 4 Animal Kingdom

Question 11.
What are cnidoblasts?
Answer:
Some ectodermal cells are specialised in food capturing and defending the body. Such cells are called cnidoblasts in coelenterates.

Question 12.
What is metagenesis?
Answer:
In some organisms sexual reproduction alternate with asexual reproduction on a regularly, basis. This alternation of generations is called metagenesis.

Question 13.
What is an acoelomate animal?
Answer:
An animal without a body cavity is called an acoelomate,
eg: Planaria, Liverfluke, Tape worm.

Question 14.
Why is the nervous system called ladder like in flatworm?
Answer:
There are two longitudinal nerve cords. These are inter connected, and look like a ladder.

Question 15.
What is a syncitial epidermis?
Answer:
In round worms, the epidermis is a multinucleated sheet of cytoplasm. It is called syncitial epidermis.

Question 16.
What is a pseudocoelom? Give an example.
Answer:
Body cavity without being lined with epithelium, is called pseudocoelom. eg: Roundworms.

Question 17.
What is a metamfcric segmentation?
Answer:
In some organism body is segmented externally by grooves, and internally by septae. This is called a metameric segmentation.

Question 18.
What are nephridia?
Answer:
Nephridin are ectodermal tubular, segmentally arranged structures helping in excretion in an organism.

1st PUC Biology Question Bank Chapter 4 Animal Kingdom

Question 19.
What is ecdysis?
Answer:
Ecdysis is a process of shedding the exoskeleton at intervals.

Question 20.
What is a haemocoel?
Answer:
A body cavity filled with blood is called haemocoel as in insects.

Question 21.
What is a mantle?
Answer:
The body covering made of a soft membranous layer in mollusca is called pallium or mantle.

Question 22.
What is haemocyanin?
Answer:
Haemocyanin is the respiratory pigment in mollusca.

Question 23.
What are the functions of the ambulacra] system?
Answer:
Ambulacral system helps in movement, feeding and respiration.

Question 24.
What is a notochord?
Answer:
Noto chord is the dorsal rod like supporting structure in chordates.

Question 25.
What is heterocercal fin?
Answer:
The tail fin of cartilageous fishes with two asymmetrical lobes is called heterocercal fun.

Question 26.
Give an example for legless amphibian.
Answer:
Icthyophis is an amphibian without legs.

1st PUC Biology Question Bank Chapter 4 Animal Kingdom

Question 27.
What is an oviparous animal?
Answer:
An animal which lays eggs outside is called an oviparous animal.

Question 28.
What are peneumatic bones?
Answer:
Bones filled with air spaces are called pneumatic bones.

Question 29.
Define metamerism?
Answer:
Metamerism is the segmentation or division of the body of an animals along its length into similar parts called metameres.

Question 30.
What are flame cells?
Answer:
Flame cells are the excretory organs of phylum platyhelminthes. They are known as solenocvtes.

Question 31.
What is a psendocoelom?
Answer:
The body cavity which is not lined by coelomic epithelium is known as pseudocoleom.

Question 32.
Name the various respiratory organs of phylum arthropoda?
Answer:
Gills, Trachea or Book lungs, and general body surface.

Question 33.
Name the phylum which consists of pseudocod?
Answer:
Aschdrainthes.

1st PUC Biology Question Bank Chapter 4 Animal Kingdom

Question 34.
What Is eueoelomats?
Answer:
Eucoekmmta Is the group of animals with true body cavity, which is lined by eodctnie epithelium.

Question 35.
Name the phylum the which the canal Systran is. seen.
Answer:
Phylum porifera.

Question 36.
What is syrinx?
Answer:
The voice box of birds is known as syrinx.

Question 37.
Name the group of animals in which horny epidermal scales are present
Answer:
Reptiles.

Question 38.
Mention the functions of water canal system.
Answer:
It helps in nutrition, respiration, excretion and reproduction.

Question 39.
What is the composition of exoskeleton in Arthropods?
Answer:
Ghitin, a rigid polysaccharide.

Question 40.
Mention the respiratory structures of echinodermater?
Answer:
Dermal branchiae, genital bursae and cloacal respiratory trees.

Question 41.
Define Ecdysis.
Answer:
The process of shedding of exoskeleton or skin is known as ecdysis or moulting.

Question 42.
Mention the functions of tube feet.
Answer:
Tubefeet are locomotory and respiratory in function.

Question 43.
Which phylum includes spiny skinned animals?
Answer:
Phylum echinodermata.

Question 44.
What is radula?
Answer:
Radula is the grasping organ which helps in feeding in molluscans.

1st PUC Biology Question Bank Chapter 4 Animal Kingdom

Question 45.
In which phylum do you find an Ambulacral system?
Answer:
Phylum Echinodermata.

Question 46.
What are Cnidoblasts?
Answer:
Cnidoblasts are the stinging cells present in the ectoderm of coelenteates. These secrete a neurotoxin.

Question 47.
What are parapodia?
Answer:
Parapodia are the locomotor organs of phylum Annelida.

Question 48.
Name the largest phylum in kingdom animaiia?
Answer:
Arthropoda.

Question 49.
Name the phylum in which synchitial epidermis is present.
Answer:
Phylum Aschelminthes.

Question 50.
What is synchitial epidermis?
Answer:
Cytoplasmic sheath with scattered nuclei is known as syncytium or synchitiaepidermis. Here cell boundaries are absent.

Question 51.
What is cephalisation?
Answer:
The process of formation of head is known as cephalisation.

Question 52.
Give two examples for flightless birds.
Answer:
The common flightless birds are Kiwi, Emu, Ostrich etc.

Question 53.
Define the term mammal.
Answer:
A mammal is an animal with mammae or the milk secreting glands.

Question 54.
Water Vascular system is the characteristic of which group of the following
(a) porifera
(b) ctenophore
(c) Echinodermata
(d) chordate
Answer:
(a) porifera.

1st PUC Biology Question Bank Chapter 4 Animal Kingdom

Question 55.
“All vertebrates are chordates but all chordates are not vertebrates”. Justify the statement.
Answer:
All chordates have of notochord presence in some stage of their life. Only in vertebrates, this notochord present in embryonic stage, is replaced by a vertebral column during the adult stage.

Question 56.
How Important is the presence of an Air bladder in Pisces?
Answer:
The class Osteichthyes possesses an Air bladder. It helps the organism in regulating buoyancy. If the air bladder were absent, the animal has to swim constantly, to avoid sinking.

Question 57.
Segmentation in the body is first observed in which of the following
(a) Plahyhelminthes
(b) Aschelminthes
(c) Annelida
(d) Arthropoda.
Answer:
(c) Annelida.

Question 58.
In which phylum do you find flame cells?
Answer:
Platyhelminthes.

Question 59.
Name a limbless amphibian
Answer:
Icthyophis.

Question 60.
Mention the function of tube feet.
Answer:
Tubefeet are locomotory and respiratory in function.

Question 61.
Name the group,of animals that possess ostia.
Answer:
Poriferans.

Question 62.
What is tissue grade of body organisation?
Answer:
If an animal body made up of well defined tissues, then it is called tissue grade of body organisation. ,

Question 63.
What is a pseudocoleom?
Answer:
The body space between the digestive tract and body-wall encloses a cavity which is not lined by epithelialayer is called a pseudocoelom.

Question 64.
Name a fresh water sponge.
Answer:
Spongilla.

1st PUC Biology Question Bank Chapter 4 Animal Kingdom

Question 65.
What is meant by holophytic nutrition?
Answer:
Plant like nutrition which is carried out by photosynthesis, is called holophytic nutrition.

Question 66.
Give an example for the class Hexactinellida?
Answer:
eg: Hyalonema.

Question 67.
In which phylum do you find flame cells?
Answer:
Platyhelminthes.

Question 68.
What is moulting?
Answer:
Periodic casting off of exoskeleton in arthropods.

Question 69.
Give an example for class scyphozoa?
Answer:
eg: Aurelia.

Question 70.
What is meant by sexual dimorphism.
Answer:
If the male and female organisms can be distingusihed based on their external appeamce, it is called as sexual dimorphism.

Question 71.
What is haemolymph?
Answer:
The colour less blood present in arthropods is called haemolymph.

1st PUC Biology Question Bank Chapter 4 Animal Kingdom

Question 72.
Which animal forms a connecting link between Annelida and Arthropoda?
Answer:
Peripatus.

Question 73.
What is mantle?
Answer:
It is a thick fold of skin covering the soft body of molluscs.

Question 74.
Give an example for class monoplacophora?
Answer:
eg. Molluscs.

Question 75.
Give an example for class monoplacophora?
Answer:
eg: Neopalina.

Question 76.
What the main component of the shell in a mollusc?
Answer:
eg: Calcium carbonate.

Question 77.
Name the respiratory organ of molluscs.
Answer:
Gills or ctenidia.

Question 78.
What are ommatidia?
Answer:
The subunits present in the compound eye of arthropoda, are called ommatidia.

Question 79.
Define cephalisation?
Answer:
Formation of a distinct head by the fusion of anterior body segments is called as cephalisation.

Question 80.
Name the part secreting the shell in mollusca.
Answer:
Mantle.

1st PUC Biology Question Bank Chapter 4 Animal Kingdom

Question 81.
Protozoans are considered as acellular animals. Why?
Answer:
The body of protozoans is made up of a mass of protoplasm, and is not differentiated into cells, therefore they are called as acellular animals.

Question 82.
Name the phylum in which a water vascular system is present?
Answer:
Echinodermata.

Question 83.
What are cold blooded animals?
Answer:
Animals which can adjust their body temperature according to their surroundings are called as coldblooded animals or poikilotherms.

Question 84.
Mention the function of malphigian tubules?
Answer:
Excertion.

Question 85.
Name the respiratory organs of reptiles?
Answer:
Lungs.

Question 86.
What is meant by cleodoic egg?
Answer:
A fertilised egg which is covered by calcareous outer covering is called a cleodoic egg.

Question 87.
How many chambers are present in the heart of birds?
Answer:
Four.

1st PUC Biology Question Bank Chapter 4 Animal Kingdom

Question 88.
Name the voice box of birds?
Answer:
Syrinx.

Question 89.
Mention the class of whales?
Answer:
Mammals.

Question 90.
Name an egg laying mammal?
Answer:
Duck bijled Platypus.

Question 91.
What is polymorphism?
Answer:
Presence of more than distnct morphological body forms in the- life cycle of an organism is called polymorphism.

Question 92.
Mention the locomotory organelles of annelids.
Answer:
Setae on parapodia.

Question 93.
Name the larva of sponges?
Answer:
Amphiblastula or parenchymula.

Question 94.
What is metagenesis?
Answer:
The lifecycle of coelentrata exhibits alternation of the polyp and medusoid generations which is called metagenesis.

Question 95.
What are pneumatic bones?
Answer:
Hollow bones filled with airsacs in birds is called as pneumatic bones.

1st PUC Biology Question Bank Chapter 4 Animal Kingdom

Question 96.
What are amniotes?
Answer:
Chordates having an extraembryonic membrane called amnion, covering the embryo are called amniotes.

Question 97.
Give an example for limbless reptile.
Answer:
Snake.

Question 98.
Give an example for pouched mammal.
Answer:
Kangaroo.

Question 99.
What are diploblastic animals? Give an example.
Answer:
Animals whose body wall is made up of two germ layers, are called as diploblastic animals, eg: Hydra.

Question 100.
Define eucoelomate condition with an example?
Answer:
Presence of a coelomic cavity lined by coelomic epithelium is called as eueoelomate condition.
eg: Arthropoda.

1st PUC Biology Animal Kingdom Two Marks Questions and Answers

Question 1.
What is bilateral symmetry? Give an example.
Answer:
Bilateral Symmetry: The body is divisible into two halves in only one lateral plane.
eg: Platyhelminthes to chordates.

1st PUC Biology Question Bank Chapter 4 Animal Kingdom

Question 2.
What is haemocoel? Give an example.
Answer:
Haemocoel is the body cavity of many invertebrates which includes arthropods and molluscs. It is found where the hemolymph circulates. Haemocoel is the fluid found in the circulatory system of phylum arthropoda.

Question 3.
What is organ system grade of body organisation? Give an example.
Answer:
Organ system grade: In this case, cells are grouped into tissue, tissues into organs and organs into organ systems. eg: Aschelminthes and other higher level animals.

Question 4.
What is a spongocoel?
Answer:
The large cavity in the centre of a sponge body, is called spongocoel. Water entering spongocoel is sent out through osculum.

Question 5.
Define radial symmetry and given an example.
Answer:
Radial symmetry is one in which a body can be divided into a number of radial planes. That is, similar parts arranged around a central axis just like the spokes of a wheel.

Question 6.
Give two characters of Phylum Platyhelminthes showing a higher body organisation seen than in coelentenates.
Answer:
Flatworms are placed above coelenterata because of several advanced features like.
(a) Triploblastic. i.e., having three body layers namely ectoderm, endoderm and mesoderm.
(b) Nervous system, excretory system etc. are better developed.

Question 7.
What is cephalisation? Give suitable examples.
Answer:
Development of head is called cephalisation. In the head, brain, sense organs are all concentrated. In annelids, arthropods, a few anterior segments combine to form the head.
eg: (a) Nereis (b) Millipede.

1st PUC Biology Question Bank Chapter 4 Animal Kingdom

Question 8.
What is a Coelom? Describe.
Answer:
The cavity, present between the body wall and the digestive canal is called coelom. It is usually lined by coelomic epithelium, as in earthworm.
They are 3 types:
Sponges, coelentarates and flatworms are acoelomates. Nematodes are pseudocoelomates while annelids are eucoelomates.

Question 9.
List out four unique characteristics of Phylum Mollusca.
Answer:
(1) They have soft bodies and are unsegmented animals.
(2) They have an external shell.
(3) Body has a covering of mantle or pallium.
(4) Foot is ventral and muscular.

Question 10.
List out four salient features of Phylum Porifera.
Answer:
The following are the salient features of Phylum Porifera.
(1) Sponges are multicellular animals. Their cells are not integrated to form tissue. Thus these exhibit cellular grade of body construction only.
(2) They are aquatic, and sedentary in habit. Majority of spionges are marine and inhabbit from shallow waters to a depth of 5,600 metres in oceanic water. A few are fresh water inhabitants.
(3) They may be solitary or colonial. The size and the shape a considerably, among members of different groups.
(4) There are numberious opening all over the body called ostia or dermal pores through
which, water enters the body.

Question 11.
Classify the Phylum Porifera and give examples.
Answer:
The Phylum Porifera comprising sponges is classified into three classes i.e., Calcaria, Hexactinellida, and Demospongia.
Class 1. Calcaria: These are sponges with spicules made up of calcium,
eg: (1) Sycon
(2) Grantia.

Class 2. Hexactinellida: These have six spicules. Silica is the substance of the spicules,
eg: (1) Venus flower basket
(2) Hyalonema.

Class 3. Demospongia: This class includes sponges having spicules made up of silica or spongin or both.
eg: (1) Spongilla
(2) Bath sponge.

1st PUC Biology Question Bank Chapter 4 Animal Kingdom

Question 12.
How useful is the study of Body cavity and coelom, in the classification of animals?
Answer:
Presence or absence’of a cavity between the body wall and the gut wall, is very important in classification. The body cavity which is lined by coelomic epithelium is called Eucoelom. Animals possessing eucoelom are called Eucoelomates (e.g: Annelids, Molluscs, Echinoderms, Chordates etc).

In some animals, body cavity is not lined’ by mesoderm lining of coelomic epithelium, but mesoderm is present as scattered pouches in between the ectoderm and endoderm. Such a body cavity is called pseudocoelom and these animals are Pseudocoelomates. In some animals, body cavity is absent and such animals are called Acoelomates.

Question 13.
Distinguish between intracellular and extracellular digestion?
Answer:
Intracelluar Digestion: It occurs within the individual cells. Products of digestion, diffuse out into the surrounding cytoplasm.

Extracellular Digestion: This occurs outside the individual cells, generally in a cavity. The products of digestion pass on to the transport system, for distribution and absorption by individual cells.

Question 14.
What Is the difference between direct, and Indirect development?
Answer:
Direct Development: In this case the young offsprings resemble the adult i.e., no intermediate stage, eg: Humans, Birds etc.

Indirect Development: This case the young ones doesn’t resemble the adult but undergo morphological changes to become adult, eg: Frogs go through the tadpole stage before becoming adult frogs. Butterflies have larvae and cocoon stage before becoming butterfly etc.

1st PUC Biology Question Bank Chapter 4 Animal Kingdom

Question 15.
What are the peculiar features that you find in parasitic platyhelminthes?
Answer:
Suckers and spines occur for attachment. Cuticle covering the body is resistant to digestive enzymes. Digestive organs, respiratory organs, circulatory system, sense organs and nervous system are simple or absent.

Question 16.
Could the number of eggs of young ones by an oviparous and a viviparous mother be equal? Why?
Answer:
Normally the number of eggs produced by oviparous is greater than that ones by viviparous. The development of young ones, in oviparous, takes place outside the mother whereas in the viviparous, the development of embryo takes place inside the uterus of mother hence a viviparous mother can have only a very limited number of embryos at a time in her uterus. Oviparous mother have no need to feed their young ones (embryos) until hatched. Hence, is large number.

Question 17.
Prepare a list of some animals that are found parasitic on human beings.
Answer:
(a) Taenia (tapeworm)
(b) Fasciola (liver fluke).
(c) Ascaris (round worm)
(d) Wachereia (filaria worm).
(e) Ancylostoma (hook worm).
(f) Hirudinaria (blood sucking leech).

Question 18.
What is sexual dimorphism? Give one example.
Answer:
External morphological differentiation of male and female organisms within a species is called as sexual dimorphism, eg: Cockroach.

1st PUC Biology Question Bank Chapter 4 Animal Kingdom

Question 19.
What is pseudocoelomate? Give one example.
Answer:
Coelomic cavity which is not lined by non coelomic epithelium is called as pseudocoelomate condition, eg: Ascaris.

Question 20.
Classify Phylum Annelida into various classes with examples.
Answer:
Phylum Annelida is classified into 3 classes, based on the locomotory organelles Namely,
(a) Class polychaeta. eg: Nereis.
(b) Class oligochaeta. eg: Earthworm.
(c) Class hirudinea. eg: Hirudinaria.

Question 21.
Define Metamerism and Cephalisation?
Answer:
Metamerism : If the animal body is divided into definite segments which are similar it is called as metamerism.
Cephalization : It is the formation of a distinct head in the anterior part of the animal body, eg: Annelida.

Question 22.
Name the extra-embryonic membranes of reptiles.
Answer:
Amnion and Allantois.
Mention the functions of the following:
(a) Trachea – Respiration in Anthropoda.
(b) Flame cells – Excretory organs of platyhelmirithes.
(c) Suckers – Help in attachment to the host body.
(d) Contractile vacuole – Osmoregulation and excretion.

Question 23.
Write any four salient features of class Aves.
Answer:
class Aves.
Birds (Aves) are warm-blooded vertebrates with a constant body temperature, and with an exoskeleton of feathers. Feathers are nothing but completely modified epidermal scales (of reptiles). Aves resemble reptiles, and at the same time, they are extremely modified, and superior to them. Hence. birds are also kni as “Glorified Reptiles”.
1. Birds are homeothermic (warm’blooded) animals.
2. Body is boat shaped and is adaptad in such a way as to offer the least resistance while flying.
3. Body is differeñtiated into a head, long neck, a trunk and a short tail.
4. Body is covered by feathers, which provide insulation.
5. Forelinibs are modified into wings for flight. Wings are provided with feathers, which are
bad conductors of heat.
6. The hind limbs are shifted forwards to balance the body while walking. They are variously modified for perching, walking. running, swimming etc.,
7. Hind limbs have 4 toes and are covered. with epidermal scales.
8. Endoskeleton is fully ossified (bony). Bones are tubular and hollow fond have air cavities or air sacs (pneumatic bones).
9. Bones of the skull are fused.
10. Jaws are devoid of teeth but covered by horny sheaths and are modified to form a beak.
11. Beak is variously modified to suit the individual food habits.

Question 24.
Write any four differences between chordates and non-chordates.
Answer:
Name the phyla in which you come across the following:
(a) Gastro vasular cavity – Coelenterate.
(b) Pseudocoel – Nematoda.
(c) Jointed legs – Arthropoda.
(d) Flame cells – Platyhelminthes.

Question 25.
Classify Phylum Porifera with an example for each class.
Answer:
The phylum porifera include the spónges, which are primitive multicellular animals without
any true tissues or organs.

1st PUC Biology Question Bank Chapter 4 Animal Kingdom

General characters:-
1. Sponges are all aquatic. Majority of them are marine and some are found in fresh waters.
2. Sponges are either solitary or colonial.
3. They are sedentary animals found attached to any suitable substratum.
4. The shape of the body vâries considerably. Some are cylindrical or vase shaped, a few are star shaped, finger like some are and even irregular forms are present

Question 26.
Classify Phylum Coelenterata with an example for each class.
Answer:
Members of this up are multicellular with a tissue grade of organisation, therefore they are included in the sub kingdom. (Bumetazoa).

General characters:
1. Coelenterates are all aqùatic, most of them are marine and a few are fresh watcr forms.
2. Members are multicellular and the cells are compactly arranged to form defmite tissues.
3. Coelenterates exhibit radial symmetry.
4. These organisms have two germ layers viz, outer ectoderm and inner endoderm, and thus they are diploblastic. Between these two cellular germ layers, is a thick non-celluar gelatinous mesoglea.
5. Twó distinct types of individuals are seen in poly or hydra like (hydroid) type and the medusoid type.
6. Some forms exhibit polymorphism (eg: Obelia).

Question 27.
Classify Phylum Platyhelminthes with an example for each class.
Answer:
Phylum Platyhelminthes
1. They are free living (aquatic or terrestrial) or parasitic.
2. Members of the phylum have a soft vermiform, dorsoventrally flattened, leaf like or tape like body.
3. Symmetry is bilateral, an anterior or head end, or posterior or tail end, an upper or dorsal surface, a lower or ventral surface, right and left sides can be recognised.
4. They are triploblastic. The body wall posseses three distinct germ layers viz ectoderm,encloderm and mesoderm.
5. They are acoelomates, that is a definite coelom ¡s absent. Body space between the various organs are filled with parenchyma cells.
6. The body wall consists of a single layered epidermis, which is ciliated in free living forms, while in parasitic forms a tough cuticle is present.
7. Flat worms show cephalisation (that is formation of head).
8. Flat worms have definite organs and hence these are the first animals with organ grade of organisation.

Question 28.
Name the phyla in which the following are present.
(a) Spicules – Phylum Porifera.
(b) Flamecells – Phylum Platyhelminthes.
(c) Shell – Phylum Mollusca.
(d) Ostia – Phylum Porifera.

Question 29.
Name the phyla in which the following are present
Answer:
(a) Tube feet – Phylum Echinodermata.
(b) Parapodia – Phylum Annelida.
(c) Pseudopodia – Phylum Protozoa.
(d) Stinging cells – Phylum Coelentarata.

Question 30.
What are acoelmates? Give an example.
Answer:
Animals without body cavity are called acoelmates.
Example: Platyhelminithes.

Question 33.
Mention the level of animal classification based on body cavity.
Answer:
On the basis of body cavity, animals can be classified into the following.
(1) Acoelmates e.g: platyheminthes.
(2) Pseudocoelomate e.g: aschelminthes.
(3) Coelomates e.g: annelida to chordata.

Question 34.
Define hermophrodites with an example.
Answer:
Hermophrodites are animals which both the sex organs e.g: Annelida.

Question 35.
Name the two basic body forms of cnidarians?
Answer:
(1) Polyp form (asexual reproduction).
(2) Medusoid form (sexual reproduction).

Question 36.
Define metagenesis with an example.
Answer:
Alternation of generation is called metagenesis.
Example: Coelentrates.

1st PUC Biology Question Bank Chapter 4 Animal Kingdom

Question 37.
What are the functions of comb plates?
Answer:
The eight comb plates help in locomotion.

1st PUC Biology Animal Kingdom Three Marks Questions and Answers

Question 1.
What are the reasons that you can think for the Arthropoda to constitute the largest group of the animal kingdom?
Answer:The following might be the reasons for the arthropods to be the largest group of animal kingdom.
(1) They are the first phylum to have well developed digestive, circulatory and respiratory systems.
(2) Their body is covered by ch itinous exoskeleton which helps them survive extreme conditions.
(3) They are usually small and reproduce heavily compared to all other phyla and hence constitute a higher number.
(4) They have highly developed sensory organs like antenna, eyes (compound and simple) statocysts etc., which helps them keep themselves safe from predators. Arthropoda can be found every where in the world, even in the volcanic springs where survival is of greater challenge. They are present in water, air and on land and they have evolved themselves to suit to all conditions.
(5) They are omnivores and can feed on both plant and animal matter.
(6) Organisms are present in all the types of habitats i.e., aquatic, terrestrial and arboreal.

1st PUC Biology Animal Kingdom Five Marks Questions and Answers

Question 1.
List the salient features of Phylum Annelida.
Answer:
Annelida and the remaining phyla under kingdom Animalia posses a true body cavity, hence are included under the grade eucoelomata.

A principal feature of this phylum is the division of the body into similar parts or segments or metameres, marked externally by transverse grooves and internally by septa. Each segment or metamere posses the representatives of all the organs of the body namely blood vessels, ‘muscles, nerves, excretory and reproductive organs. This phenomenon is known as . segmentation or metamerism,

Annelids show cephalisatiqn union of a few of the anterior body segments to form a head which is specialised by the development of nervous, sensory and feeding structures.

General characters:-
1. Annelids are mostly aquatic-either marine or fresh water forms. Some are terrestrial-burrowing, free living Or sedentary forms. A few are ectoparasites.

2. Annelids are bilaterally symmetrical, triploblastic, eucoelomate and segmented animals.

3. The body is soft, cylindrical or dorsoventrally flattened, vermiform with cephalisation at the anterior end.

4. The body is protected by a thin cuticle which is secreted by the underlying epidermal cells.

5. The body wall is dermo muscular (dermis with muscle cells or .fibres), therefore can twist and turn or highly contractile in nature.

6. Body cavity is a true coelom lined by coelomic epithelium, the coelom is formed by splitting of embryonic mesoderm and hence it is described as ‘schizocoelous’ or ‘schizocoelic’ made of formation and the coelom as ‘schizocoeP.

7. Digestive system is a straight tubular structure and is complete with a mouth and anus. It
also shows regional differentiation into parts like buccal cavity, pharynx, oesophagus, gizzard, intestine and rectum. ’
The digestive system shows segmental specialisation.

8. Annelids are the first group having blood vascular system. A definite circulatory system
or blood vascular system is present which consists of blood and blood vessels. Blood flows only in definite blood vessels, hence the circulatory system is described as ‘closed type’ of circulatory system. Blood is red in colour due to the presence of haemoglobin in the plasma,

9. Respiration occurs by simple diffusion through the body surface or through respiratory
structures called gills.

10. Excretory system consists of coiled ectodermal tubes called nephridia, though which excretion takes place.

1st PUC Biology Question Bank Chapter 4 Animal Kingdom

11. The nervous system is well developed consisting of a nerve ring and a double ventral nerve cord.

12. Characteristic locomotory structures are usually present, either in the form of chitinOus setae or fleshly lateral extensions called parapodia.

13. Reproduction is usually by sexual mode. Members may be either bisexual or unisexual.

14. Development may be direct or indirect, where the larval stage present is represented by a trochophore larva.

Question 2.
Enumerate general characteristics of Phylum Arthropoda.
Answer:
1. The phylum Arthropoda is the largest phylum of the animal kingdom. It includes more than 80% of all. the known animals. They are found in marine, terrestrial and aerial habitats.
2. They are the only major invertebrates adapted to live on dry land.
3. Insects among arthropods are the only invertebrates capable of flight. More than about10,00,000 species of arthropods have been described so far.

General characters:-
1. Arthropods are bilaterally symmetrical, triploblastic, metamerically segmented and eucoelomates.

2. Segmentation of the body is less apparent and the number of segments is fewer in number.

3. They show the highest degree of cephalisation, that is formation of a well developed head.
Head is usually formed by the fusion of six body segments. Following the head region is the trunk which is usually divisible into an anterior thorax and a posterior abdomen.

4. Their body segment usually bears paired lateral and jointed appendages. A segment of the appendage is known as podomere. The appendages are variously modified in different groups and even in different parts of the same animal. A few appendages close to the mouth are modified into jaws and are helpful in feeding. A few appendages are sensory in function  Some appendages helpjri locomotion. Due to the presence of jointed appendages or legs for locomotion, the phylum gets the name Arthropoda, which means jointed feet.

5. Their body is covered externally by an exoskeleton made up of chitinous cuticle. In each segment, the chitinous cuticle forms a dorsal convex tergum, a ventral sternum and two lateral pleura.

6. The exoskeleton is periodically cast off, and regrown at regular intervals. This is redundant. This periodic casting off of the exoskeleton is known as ecdysis or moulting.
The presence of chitinous exoskeleton does not permit free growth of the animal, to over come this problem, the exoskeleton is periodically cast off.
The stages between the series of moults are called instars. The animal grows during intervals between successive moults.

7. Muscles are present, which are segmentally arranged in bundles.

8. The body cavity is filed with blood and such a cavity or coelom is known as a hemocoel.
The hemocoel doesn’t bear the lining of coelomic epithelium.. The true coelom is reduced and is confined to the spaces of excretory and genital organs.

1st PUC Biology Question Bank Chapter 4 Animal Kingdom

9. The digestive system is well developed and is complete with a mouth and a posterior anus. Mouth parts trophi surrounding the mouth are used in feeding.

10. The circulatory system is of open type, where the blood flows through a system of ill defined channels or sinuses. The various organs are indeed bathed in blood. Hemocoel is a part of open circulatory system. A dorsal pulsatile heart is present.

11. Respiration is either through body surface through gills or through trachea or book lungs.

12. Excretion takes place through green glands [coelomic duct] or by malpighian tubules. The nitrogenous waste products are excreted “4n the form of uric acid.

13. Nervous system consists of paired dorsal cerebral ganglia forming brain and a double ventral nerve cord with segmental ganglia.

14. Sense organs comprise of simple eyes or compound eyes with mosaic vision, chemoreceptors and tactile sense organs.

15. In some forms, the endocrine glands are well developed. Even moulting is under the control of a hormone called ecdysone, secreted by the endocrine glands.

16. Sexes are usually separate and a few exhibit sexual dimorphism. Fertilised eggs are yolky enclosed in a shell. Fertilisation is generally internal.

17. Development may be direct or indirect. When indirect, the larval forms undergo varying degrees of metamorphosis to become adult ones.

18. Majority of the forms are oviparous.

Classifications: .
Phylum Arthropods is divided into the following classes:-
1. Class: Crustacea: [crusta – hard shell], eg: Prawn,lobsters, crab etc.
2. Class: Insects or Hexapoda [Insecterm – cut into], eg: Butterfly, honey bee etc.
3. Class: Diplopoda [Diplos – double, podos – feet], eg: Julus (millipede).
4. Class: Chilopoda. eg: Centipede.
5. Class: Arachnids, eg: Scorpion, spider etc.
6. Class: Onychophora. eg: Peripatus.

Question 3.
List the salient features of Phylum Porifera.
Answer:
1. Sponges are all aquatic. Majority of them are marine and some are found in fresh waters.

2. Sponges are either solitary or colonial.

3. They are sedentary animals found attached to any suitable substratum.

4. The shape of the body varies considerably. Some are cylindrical or vase shaped, a few are star shaped, fingerlike some are and even irregular forms are present

5. The surface of the body is perforated by numerous miflute pores, called ostia or dermal pores through which water enters the body. These ostia lead to inter communicating canal system of the body (which maintains the flow of water current) and finally into the central cavity called the spongocoel or paragastric cavity. Spongocoel opens to the outside by one or two large openings called

6. The body wall consists of an outer dermal layer or pinnacoderm and an inner gastral layer or choanoderm. In between these two layers a gelatinous mesenchyme is present, eg: The dermal layer is composed of thin flattened polygonal cells called pinacocytes which ate compactly arranged.

7. The gastral layer contains choanocytes or collar , cells. Each choanocyte is round or oval with a large nucleus and a flagellum. These choanocytes are found living in spongocoel. The gelatinous mesenchyme contains free amoeboid cells of various types.

  • Chromocytes → Pigment cells. .
  • Trophocytes → which collect incompletely digested food.
  • Scleroblasts → which secrete spicules.

Usually all sponges have an. internal skeleton or endoskeleton made up of rigid frame work of needlelike structures called spicules. (Chemically made up of protein fibres called spongin or silica or CaCO3.

Question 4.
Enumerate general characteristics of Phylum Platyhelminthes.
Answer:
General characters:-
1. They are free living (aquatic or terrestrial) or parasitic.
2. Members of the phylum have a soft vermiform, dorsoventrally flattened, leaf like or tape like body.
3. Symmetry is bilateral, an anterior or head end, or posterior or tail end, an upper or dorsal surface, a lower or ventral surface, right and left sides can be recognised.
4. They are triploblastic. The body wall posseses three distinct germ layers viz ectoderm, endoderm and mesoderm.
5. They are acoelomates, that is a definite coelom is absent. Body space between the various organs are filled with parenchyma cells.
6. The body wall consists of a single layered epidermis, which is ciliated in free living forms, while in parasitic forms a tough cuticle is present.
7. Flat worms show cephalisation (that is formation of head).
8. Flat worms have definite organs and hence these are the first animals with organ grade of organisation.
9. Digestive system may be present (as in free living forms) or absent (as in many endoparasites). When present, the digestive system is branched and has only one opening called the mouth. Hence it is described as being incomplete.
10. Respiratory organs are absent. Respiration occurs through the body surface by the process of simple diffusion.
11. Excretion is carried out by a group of specialised cells called as ‘Flame cells’ or ‘solenocyte’, which open into a pair of longitudinal excretory canals. These canals open to the exterior through a single excretory pore.
12. The nervous system comprises of a pair of anterior nave ganglia (brain) with longitudinal nerve cords, which are connected by transverse nerves called commissures. This type of nervous system is called ladder type of nervous system.
13. Simple sense organs in the form of Eyespots are present in free living forms.
14. Reproduction is by sexual mode. Members are bisexual (hermaphrodites). The reproductive system is complete with gonads, ducts and accessory glands.
15. Fertilisation.is internal, either cross fertilisation or self fertilisation occurs.
16. Development may be either direct (as in free living forms) or indirect (as in parasites). In parasites, the life cycle is usually complicated and it completes in one or several intermediate hosts.

1st PUC Biology Question Bank Chapter 4 Animal Kingdom

Question 5.
Enumerate general characteristics of class Aves.
Answer:
Birds (Aves) are warm-blooded vertebrates with a constant body temperature, and with an exoskeleton of feathers. Feathers are nothing but completely modified epidermal scales
(of reptiles). Aves resemble reptiles, and at the same time, they are extremely modified, and superior to them. Hence. birds are also knáwn as “Glorified Reptiles”.
1. Birds are homeothermic (warm’blooded) animals.
2. Body is boat shaped and is adapted in such a y as to offer the least resistance while flying.
3. Body is differeñtiated into a head, long neck, a trunk and a short tail.
4. Body is covered by feathers, which provide insulation.
5. Forelimbs are modified into wings for flight. Wings are provided with feathers, which are bad conductors of heat.
6. The hind limbs are shifted forwards to balance the body while walking. They are variously modified for perching, walking, running, swimming etc.,
7. Hind limbs have 4 toes, and are covered with epidermal scales.
8. Endoskeleton is fully ossified (bony). Bones are tubular and hollow fond bave air cavities or air sacs (pneumatic bones).
9. Bones of the skull are fused.
10. Jaws are devoid of teeth but’ covered by horny sheaths and are modified to form a beak.

Question 6.
Enumerate general characteristics of class Reptiles.
Answer:
Reptilians were the dominant group of vertebrates during ‘the Mesozoic period which was known as the ‘golden age of reptiles’. They are the first group of vertebrates to have developed completely for land life (terrestrial life).
1. Reptiles are poikilothermic (cold blooded) animals, which are completely adapted for terrestrial mode of,lifé; but some have secondarily adapted for aquatic mode of life.
2. Body is usually divisible into head, neck, trunk and tail.
3. The skin is dry, and covered by hard, horny, epidermal scales or. scutes, which protect the animal from desiccation and from predators. The epidermal scales from a sort of exoskeleton to the dry skin. Skin is devoid of skin glands.
4. The head region possesses a mouth guarded by jaws with teeth, a pair of compound eyes, a pair of external nares and a pair of external ears (tympanic membrane). In snakes the tympanic membrane is poorly developed.
5. Trunk region possesses two pairs of pentadactyl Limbs, whose digits terminate with horny claws.
6. The eridoskeleton is bony.
7. Digestive system is complete and it is associated with digestive glands (pancreas and liver)

1st PUC Biology Question Bank Chapter 4 Animal Kingdom

Question 7.
Enumerate general characters of Mammals
Answer:
1. Class Mainmalia includes warm blooded and highly organized animals possessing mammary (milk) glands for suckling their young ones. They live almost in all the environments of the world, and undergo secondary adaptation to suit their habitats. They are also known as hair quadrupcds.
2. Mammals are all homoeothermic (warm blooded) animals.
3. The body shape varies, and it is covered by hairs.
4. Body is divisible into head, neck, trunk and tail.
5. Skin is glandular and includes sebaceous, and sweat glands in both the sexes, and mammary glands in the females.
6. Head region possesses a pair of eyes protected by eyelids and eyelashes, a pair of external ears or pinnae, and a pair of external nares.
7. They possess two pairs of pentadactyl legs, which are variously modified to perform different functions [like walking, running, climbing, swimming, burrowing and flying].
Digits bear horny claws, nails or hoofs.

Question 8.
List out the differences between Bony fishes and Cartilagenous fishes.
Answer:

Chondrichthyes Osteichthyes
• Skeleton is made up of cartilage. • Skeleton is made up of bones.
• Exclusively marine. • Both marine and fresh water forms are seen.
• They possess placoid scales. • Possess cycloid or ctenoid scales.
• Mouth and nostrils are situated on ventral side of the body. • Mouth and nostril are terminal in their position.
• Passes 5 pairs of gill slits. • Possess 4 pairs of. gill slits which are covered by operculum.
• Tail is heterocercal. • Tail is homocercal.
• Devoid of air bladders. • Possess air bladders.
• Males usually possess a pair of cjaspers.
eg: Scliodon (Shark)
Narcine (Electric ray)
Trygon (Sting ray).
• Claspers are absent.
eg: Anguilla (Fresh water Eel)
Clarias (Cat fish)
Hippocampus (Sea horse).

Question 9.
If you are given a specimen, what are the steps that you should follow to classify it?
Answer:
The following features are used as the basis of animal classification:
(1) Level of organization: Identify the level of organization like cellular, tissue, organ or organ system level of organization.
(2) Body symmetry: Identify if the animal is asymmetrical, radially or has bilateral symmetry.
(3) Diploblastic of triploblastic: Based on the presence of number of the embryonic layers. Diploblastic: Two embryonic layers as an external ectoderm and an internal endoderm. Triploblastic: Three embryonic layers as external ectodrm, middle mesoderm and an inner endoderm.
(4) Body cavity: Presence or absence of body cavity. Animals possessing coelom are called coelomates. Animals in which body cavity is absent are called acoelomates.
(5) Segmentation: Some animals show segmentation of body externally or internally.
(6) Presence of notochord: Chordates are animals with notochord and non-choidates are ones which don’t form notochord during embryonic development.
10. What are the modifications that are observed in birds, that help them fly?
Answer:
The following modifications helps birds to fly:-
(1) Presence of feathers.
(2) Presence of pneumatic bones: Pneumatic bones are long hollow bones with air cavitie.
(3) Fore limbs are modified into wings to help in flight.
(4) Hind limbs generally have scales helping them to clasp the prey in-flight or a tree branch.
(5) Excretion of uric acid, and faeces is through a single opening, and excretion uses very little amount of water, to reduce body weight.
(6) Aerodynamically built body helps in flying (by reducing friction).

1st PUC Biology Question Bank Chapter 4 Animal Kingdom

Question 11.
List the general characters of Phylum Coelenterata.
Answer:
General characters:
1. Coelenterates are all aquatic, most of them are marine and a few are fresh water forms.
2. Members are multicellular and the cells are compactly arranged to form defmite tissues.
3. Coelenterates exhibit radial symmetry.
4. These organisms have two germ layers viz, outer ectoderm and inner endoderm, and thus they are diploblastic. Between these two cellular germ layers, is a thick non-celIuar
gelatinous mesoglea.
5. Twò distinct types of individuais are seen in poiy or hydra like (hydroid) type and the medusoid type.
6. Some forms exhibit polymorphism (cg: Obelia).

Question 12.
Write the general characters of Phylum Aschelminthes. Mention two examples
Answer:
General characters:
I. Nematodes are triploblastic and bilaterally symmetrical.
2. The body is long, cylindrical, unsegmented, vermiform and usually pointed at both the ends. Hence, the members are commonly described as ‘round worms’ or ‘C-bread worms’.
3. The body is protected by a thick, tough and resistant cuticle.
4. Body wall is composed of epidermis and musculature. Epidermis is a sheet of cytoplasm with many nuclei, such as multinucleated sheet of cytoplasmic layer without septa or cross walls which is known as syncytial epidermis.
5. Body cavity occurs between the body wall and alimentary canal, but it is not lined by the mesodermal (coelomic) epithelium. Such a body cavity is called ‘pseudo coelom’.
6. The digestive system is complete with a mouth and anus.
7. Respiratory system is absent and respiration occurs by a process of simple diffusion through the body wall.
8. Excretory system is simple and consists of one or more longitudinal tube like canals. An excretory pore is present.
9. Nervous system consists of a nerve ring with longitudinal nerve cords. Even lateral nerves are seen.
10. Definite circulatory system ¡s absent.

Question 13.
List out the salient features of Phylum Annelida.
Answer:
General characters:
1. Annelids are mostly aquatic-either marine or fresh water forms. Some are terrestrial burrowing, free living or sedentary forms. A few are ectoparasites.
2. Annelids are bilaterally symmetrical, triploblastic, eucoelomate and segmented animals.
3. The body is soft, cylindrical or dorsoventrally flattened, vermiform with cephalisation at the anterior end.
4. The body is protected by a thin cuticle which is secreted by the underlying epidermal cells.
5. The body wall is dermo muscular (dennis with muscle cells or .fibres), therefore can twist and turn or highly contractile in nature.
6. Body cavity is a true coelom lined by coelomic epithelium, the coelom is formed by splitting of embryonic mesodenn and hence it is described as ‘schizocoelous’ or ‘schizocoelic’ made of formation and the coelom as ‘schizocoel’.

Question 14.
List any six characters of Phylum Arthropoda. Mention any two classes with one example for each.
Answer:
Classifications:
Phylum Arthmpoda divided into the following classes:
1. Class: Crustacea: [crusta- hard shell], eg: Prawn,. lobsiers, crab etc.
2. Class: Insecta or Hexapoda [Insecterm – cut into]. eg: Butterfly, honey bee etc.
3. Class: Diplopoda [Diplos – double, podos – feet]. eg: Julus (millipede).
4. Class: Chilopoda. eg: Centipede.
5. , Class: Arachnida. eg: Scorpion, spider etc.
6. Class: Onychophora. eg: Peripatus.

Question 15.
Classify Phylum Mollusca by giving examples for each class.
Answer:
1. Class: Moñoplacophora
eg: Ne opalina goJatheca

2. Class: Amphineura
eg: Chiton, Chaetaderma.

3. Class: Scaphopoda
eg: Dentalium (Elephant tusk shell).

1st PUC Biology Question Bank Chapter 4 Animal Kingdom

4. Class: Gastropoda
eg: Pila (Apple snail), Patdlla, Turbo Helix.

5. Class Pelecypoda (Bivalvia)
eg: Unjo (mussel), Oyster, Mytilus.

Question 16.
List out the salient features of Phylum Mollusca.
Answer:
General characters:
1. Members are mostly aquatic either marine or fresh water forms. A few are amphibious, and some are terrestrial.
2. Mollusca are Šilaterally symmetrical, triploblastic, unsegmented and soft bodied, eucolemate animals.
3. The body consists of a head, foot, visceral mass, and a mantle.
4. The head bears eyes, tentacles, and other simple sense organs.
5. The foot is ventral. It is thick, muscular, and locomotor in function.
6. The body is covered by a thick fold of skin called mantle or paflium which arises from the body wall. Mantle encloses a triangle mantle cavity which houses the gills, nephridiophores,
gonopores and anus.

Question 17.
List out the salient features of Phylum Echinodormata. Give two examples.
Answer:
General characters:
1. They are exclusively marine.
2. Echinoderms are rounded, cylindrical or star shaped organisms.
3. The body is triploblastic, eucoelomate, and unsegmented with radial symmetry. (But larvae are bilaterally symmetrical).
4. Body is generally covered by skin or exoskeleton supported by an endoskeleton made up of
calcareous plat&ossicles. From these plates spines may arise which project through the epidermis (skin).
5. Head is absent, and the body is distinguishable into oral, and aboral surfaces.
6. Coelom is extensive, enterocoelous filled with coelomic fluid, and amoebocytes.
7. They possess a characteristic Ambulacral or water vascular system.
It consists of a system of tubes which emerge as a series of pouch like projections from
the body surface as body appendages / podia / tube feet, and help in locomotion, food’capture, and respiration.
8. Alimentary canal (Digestive system) is complete with mouth on the oral surface and anus on an aboral surface.
9. Circulatory system is primitive, and reduced. It s haemal, lacular or coelomic channels.
(Thus it is an open type of circulatory system).

Question 18.
Mention the classes of Phylum Echinodermata with one example for each.
Answer:
The phylum Echinodermata is divided into two sub phyla.
1. Pelmetazoa – Echinoderms attached through out or part of their life to a substratum by means of a stalk.
2. Eleutherozoa – Devoid of stalk, and are free living forms.
Sub phylum Pelmetazoa comprises of only one class, namely Crinoidea.
eg: Antedon (sea lily), Pentacrinus

1st PUC Biology Question Bank Chapter 4 Animal Kingdom

Sub phylum Eleutherozoa comprises of 4 classes:

  • Class: Asteroidea. eg: Asterias (Star fish), Astropecten (Sea star), Solastar.
  • Class: Ophuroidea. eg: Ophiothrix (Brittle star), Ophioderma.
  • Class: Echinoidea. eg: Echinocardium (Heart urchin) Salmacis (Sea urchin).
  • Class: Holothuroidea. eg: Cucumaria, Hoíothuria (Sea cucumber).

Question 19.
Mention any six characters of class Amphibia and give examples for a limbless and a tailed Amphibian.
Answer:
(a) The class amphibian (“amphi-both” bian-life) includes cold blooded vertebrates adaed to be land and ter, as such they have made a “compromise beten the two environments”.

  • Amphibians are coi’d blooded (poikilotherms) aquatic or terrestrial , vertebrates with limbs, and lungs.
  • Body is divided into head, and trunk (but in few forms it is divided into head, neck, trunk, and tail).
  • The skin is šmooth without scales, and is always moist (due to the presence of glands). it is highly vascularised., thus cutaneous respiration is seen in an amphibian.
  • The paired fin.š of fishes are modified into limbs in amphibia. Two pairs of limbs (fore limbs, and hind limbs) are present which are pentadactyl.
  • At the head region a pair of eyes, a pair of external nostrils, mouth and a pair of eardrums are present.
  • Mouth is provided with teeth on one or both the jaws, and a movable tongue.

(b) Limbless Amphibian – Ichthyophis.
Tailed Amphibian -Amblystoma.

1st PUC Biology Animal Kingdom Text Book Questions and Answers

Animals make up millions of species. They are very diverse in form, ranging from single celled microscopic ones to multicellular macroscopic organisms.
Animals are divided into two major kingdoms:

  • Kingdom Protista and
  • Kingdom Animalia.

Kingdom Protista includes unicellular animals.

Example: Protozoans, Kingdom Animalia includes all the multicellular animals. Animals exhibit a great deal of variations in their form their sizes and their life styles are found distributed in a wide variety of habitats. As such, there is a need for classifying these animals, for their systematic study. The branch of Biology dealing with the identification, naming and classification of animals is termed as Animal Taxonomy.

The term ‘Taxonomy’ was proposed by A.P. de Candolle (1813).
Outline for the classification of Animals: (Chart)
1st PUC Biology Question Bank Chapter 3 Plant Kingdom 1
Note: The most accepted system of classification is Natural classification.

1. Levels of Organisation:
Animals have five types of body organization:-
(a) Acellular grade/Protoplasmic level: In this grade, the organisms are made of a single cell. The organization is at the level of protoplasm.
(b) Cellular grade: The body of the organisms consists of many cells which are not organized into tissues, eg: Poriferans.
(c) Tissue grade: The body of the organisms is multicellular. The cells are organized into definite tissues, eg: Coelenterates.
(d) Organ grade: The body of these multicellular animals have cells organized into tissues and tissues organized into organs, eg: Platyhelminthes.
(e) Organ system grade: In this case, cells are grouped into tissue, tissues into organs and organs into organ systems, eg: Aschelminthes and other higher level animals.

2. Body Symmetry:
Symmetry is similarity in arrangements of parts. Animals having symmetry are called symmetrical and those without symmetry are called asymmetrical.

Types of symmetry:-
(a) Radial Symmetry: The body is divisible into two halves by an vertical plane, eg: Coelenterates.
(b) Bilateral Symmetry: The body is divisible into two halves in only one lateral plane, eg: Platyhelminthes to chordates.

3. Germ Layers:
Germ layers or germinal layers, are primary layers that differentiate in the embryo at the time of gastrulation. Animals have a minimum of two germinal layers and a maximum of three germinal layers. All the tissues and organs of the body develop from germinal layers.

Types:-
(a) Diploblastic Animals: Animals having two germinal layers viz, outer ectoderm and inner endoderm are called diploblastic animals.
(b) Triploblastic Animals: Animals having three germinal layers viz, outer ectoderm, middle mesoderm and inner endoderm are called Triploblastic animals.
eg: Platyhelminthes, Aschelminthes, Annelida, Arthropoda, Mollusca, Echinodermata and Chordata.

1st PUC Biology Question Bank Chapter 4 Animal Kingdom

4. Coelom (Body Cavity):
The space between the body wall and the alimentary canal (Digestive system) is referred to as coelom. Depending upon the presence, absence and nature of coelom, animals are of the following types.
(i) Acoelomates: Here a coelomic cavity is absent. If present, it is filled with parenchyma cells which are derived from the mesoderm (thus no empty space), eg: Coelenterate, Platyhelminthes.
(ii) Pseudocoelomates: A coelomic cavity is present but it is not lined by peritoneum eg: Aschelminthes.
(iii) Coelomates: Here, a true coelom is present which is lined by peritoneum, outer parietal peritoneum and inner visceral peritoneum. Coelomic fluid is present in the codon, eg: Arthropoda, annelida, molluscans, echinoderms and chordates.

Note: In Arthropods and mollusca are blood filled cavity is present called Hemocoel. Depending on origin, these coeloms of two types.
(1) Schizocoel: Here coelom is formed by splitting of mesoderm, eg: Annelida, Arthropoda, Mollusca.
(2) Enterocoel: Coelom develops as an out growth of the enteron (Digestive system).
eg: Echinodermata, chordata.

Phylum Porifera:

The phylum porifera include the sponges, which are primitive multicellular animals without any true tissues or organs.

General characters:-
1. Sponges are all aquatic. Majority of them are marine and some are found in fresh waters.

2. Sponges are either solitary or colonial.

3. They are sedentary animals found attached to any suitable substratum.

4. The shape of the body varies considerably. Some are cylindrical or vase shaped, a few are star shaped,
fingerlike some are and even irregular forms are present

1st PUC Biology Question Bank Chapter 4 Animal Kingdom

5. The surface of the body is perforated by numerous flute pores, called ostia or dermal pores through which water enters the body. These ostia lead to inter communicating canal system of the body (which maintains the flow of water current) and finally into the central cavity called the spongocoel or paragastric cavity. Spongocoel opens to the outside by one or two large openings called oscula.

6. The body wall consists of an outer dermal layer or pinnacoderm and an inner gastral layer or choanoderm. In between these two layers a gelatinous mesenchyme is present, eg: The dermal layer is composed of thin flattened polygonal cells called pinacocytes which ate compactly arranged.
The gastral layer contains choanocytes or collar , cells. Each choanocyte is round or oval with a large nucleus and a flagellum. These choanocytes are found living in spongocoel.

The gelatinous mesenchyme contains free amoeboid cells of various types.
(a) Chromocytes → Pigment cells.
(b) Trophocytes → which collect incompletely digested food.
(c) Scleroblasts →  which secrete spicules.

7. Usually all sponges have an. internal skeleton or endoskeleton made up of rigid frame work of needlelike structures called spicules. (Chemically made up of protein fibres called spongin or silica or CaCO3.

8. Nutrition is Hoiozoic, where in the sponges feed on protozoa, diatoms, bacteria etc.

9. Digestion is intracellular.

10. Respiration is by simple diffusion.

11. Nitrogenous waste products and undigested food are eliminated from the body along with the water currents going out of the osculum.

12. Sponges reproduce by both asexual and sexual methods.

Asexual reproduction takes place by budding, Certain freshwater forms show the formation of internal buds called as gemmules. Sexual reproduction takes place by the formation and fusion of haploid spermatozoa and ova. Most of the sponges are hermaphrodites (Bisexual) that is both the sex organs are found in the same individual.

13. Development is indirect and shows the formation of two mobile larvae called amphiblastula and parenchymula during the life cycle.

14. Sponges exhibit a remarkable power of regeneration.

Classification:-
The phylum porifera is classified into 3 classes, based on the chemical nature of spicules found in the endoskeleton.
1. Class Calcaria, eg:- Sycon, Ascon.
2. Class Hexactinellida : HyalOnema (Glass rope sponge), eg:- Euplectella (Venus flower basket).
3. Class Demospongia:
eg:- Spongilla, Euspongia

Phylum Coelenterata:

Members of this group are multicellular with a tissue grade of organisation, therefore they are included in the sub kingdom. (Eumetazoa).

General characters:-
1. Coelenterates are all aquatic, most of them are marine and a few are fresh water forms.
2. Members are multicellular and the cells are compactly arranged to form definite tissues.
3. Coelenterates exhibit radial symmetry.
4. These organisms have two germ layers viz. outer ectoderm and inner endoderm, and thus they are diploblastic. Between these two cellular germ layers, is a thick non-cellular gelatinous mesoglea.
5. Two distinct types of individuals are seen in poly or hydra like (hydroid) type and the medusoid type.
6. Some forms exhibit polymorphism (eg: Obelia).
7. Skeleton when present is external, calcareous and massive.
8. The body encloses a single cavity called the gastrovascular cavity or coelenteron, which opens to the outside through the mouth. Anus is absent.,
9. Mouth is situated on an elevated portion called the hypostome or manubrium. The mouth is usually surrounded by a circle of tentacles which helps in capturing the prey. Tentacle bear nematocysts or cindoblast cells or stinging cells in them. The nematocysts bear toxic fluid in them which paralyses the prey during food capture.
10. Digestion is both extracellular and intracellular.

1st PUC Biology Question Bank Chapter 4 Animal Kingdom

11. Respiration is by simple diffusion.
12. Nitrogenous waste products are eliminated at the surface of the cells.
13. Nervous system is seen in the form of a loose network of nerve cells (nerve net) in the inner surface of ectoderm.
14. Reproduction takes place by both sexual and asexual methods.
Asexual reproduction takes place by the formation of exogenous buds.
Sexual reproduction takes place through the formation and fusion of gametes, and the sexual forms may be hermaphrodites (bisexual) or unisexual.
15. A few forms show alternation of generations in their life cycle.
16. Same members exhibit significant power of regeneration.

Classification of phylum coelenterata:
The phylum coelenterata is divided into 3 classes:-
1. Class: Hydrozoa: eg : Hydra.
2. Class: Scyphozoa: eg : Aurelia or Jelly Fish.
3. Class: Anthozoa: eg : Corals.

Phylum Ctenphora:

General characters:-
1. They are commonly known as Sea walnuts or comb jellies.
2. They are exclusively marine.
3. They are of tissue level of body organisation.
4. They have diploblastic condition, and are radially symmetrical.
5. The body bears “eight external rows of ciliated comb plates which helping in the locomotion.
6. Digestion both extracellular and intracellular.
7. Reproduction takes place only by sexual means.
8! Fertilisation is external and development is indirect.
9. Special property in ctenophores is Bioluminescence.

Phylum Platyhelminthes:

General characters:-
1. They are free living aquatic or terrestrial) or parasitic.
2. Members of the phylum have a soft vermiform, dorsoventrally flattened, leaf like or tape like body.
3. Symmetry is bilateral, an anterior or head end, or posterior or tail end, an upper or dorsal surface, a lower or ventral surface, right and left sides can be recognised.
4. They are triploblastic. The body wall posseses three distinct germ layers viz ectoderm, endoderm and mesoderm.
5. They are acoelomates, that is a definite coelom is absent. Body space between the various organs are filled with parenchyma cells.
6. The body wall consists of a single layered epidermis, which is ciliated in free living forms, while in parasitic forms a tough cuticle is present.
7. Flat worms show cephalisation (that is formation of head).
8. Flat worms have definite organs and hence these are the first animals with organ grade of organisation.
9. Digestive system may be present (as in free living forms) or absent (as in many endoparasites). When present, the digestive system is branched and has only one opening called the mouth. Hence it is described as being incomplete.
10. Respiratory organs are absent. Respiration occurs through the body surface by the process of simple diffusion.
11. Excretion is carried out by a group of specialised cells called as ‘Flame cells’ or ‘solenocyte’, which open into a pair of longitudinal excretory canals. These canals open to the exterior through a single excretory pore.
12. The nervous system comprises of a pair of anterior nave ganglia (brain) with longitudinal nerve cords, which are connected by transverse nerves called commissures. This type of nervous system is called ladder type of nervous system.
13. Simple sense organs in the form of Eyespots are present in free living forms.
14. Reproduction is by sexual mode. Members are bisexual (hermaphrodites). The reproductive system is complete with gonads, ducts and accessory glands.
15. Fertilisation.is internal, either cross fertilisation or self fertilisation occurs.
16. Development may be either direct (as in free living forms) or indirect (as in parasites). In parasites, the life cycle is usually complicated and it completes in one or several intermediate hosts.

Classification of Platyhelmanthcs:-
Phylum platyheifflinthes is. divided into three classes based on their habit and nature of digestive canal. .
1. Class: Turbellaria: eg : Planaria (Dugesia).
2. Class: Trematoda eg: Liverfluke.
3. Class: Cestoda: eg. Tapeworm.

Phylum, Aschelminthes / Nemathelminthes / Nematoda:

General characters:-
1. Nematodes are triploblastic and bilaterally symmetrical.
2. The body is long, cylindrical, unsegmented, vermiform and usually pointed at both the ends, Hence, the members are commonly described as ‘round worms’ or ‘C-bread worms’.
3. The body is protected by a thick, tough and resistant cuticle.
4. Body wall is composed of epidermis and musculature. Epidermis is a sheet of cytoplasm with many nuclei, such as multinucleated sheet of cytoplasmic layer without septa or cross walls which is known as syncytial epidermis.
5. Body cavity occurs between the body wall and alimentary canal, but it is not lined by the mesodermal (coelomic) epithelium. Such a body cavity is called ‘pseudo coelom’.
6. The digestive system is complete with a mouth and anus.
7. Respiratory system is absent and respiration occurs by a process of simple diffusion 1 through the body wall.
8. Excretory system is simple and consists of one or more longitudinal tube like canals. An excretory pore is present.
9. Nervous system consists of a nerve ring with longitudinal nerve cords. Even lateral nerves are seen.
10. Definite circulatory system is absent
1st PUC Biology Question Bank Chapter 4 Animal Kingdom
11. Reproduction is only by sexual means, pores are separate. Members exhibit sexual dimorphism4 (males and females’can be morphologically distinguished). Males are generally shorter than females.
12. Fertilization is internal.
13. Development is general indirect. However, special larval stages are absent. Growth is
usually accompanied by moulting. eg: Ascaris lumbricoides (round worm) Ancylostoma (hook worm).

Phylum Annelida:

Annelida and the remaining phyla under kingdom Animalia posses a true body cavity, hence are included under the grade eucoelomata.
A principal feature of this phylum is the division of the body into similar parts or segments or metameres, marked externally by transverse grooves and internally by septa. Each segment or metamere posses the representatives of all the organs of the body namely blood vessels, . ‘muscles, nerves, excretory and reproductive organs. This phenomenon is known as . segmentation or metamerism,

Annelids show cephalisatiqn union of a few of the anterior body segments to form a head which is specialised by the development of nervous, sensory and feeding structures.

General characters:-
1. Annelids are mostly aquatic-either marine or fresh water forms. Some are terrestrial-burrowing, free living Or sedentary forms. A few are ectoparasites.
2. Annelids are bilaterally symmetrical, triploblastic, eucoelomate and segmented animals.
3. The body is soft, cylindrical or dorsoventrally flattened, vermiform with cephalisation at the anterior end.
4. The body is protected by a thin cuticle which is secreted by the underlying epidermal cells.
5. The body wall is dermo muscular (dermis with muscle cells or .fibres), therefore can twist and turn or highly contractile in nature.
6. Body cavity is a true coelom lined by coelomic epithelium, the coelom is formed by splitting of embryonic mesoderm and hence it is described as ‘schizocoelous’ or ‘schizocoelic’ made of formation and the coelom as ‘schizocoeP.
7. Digestive system is a straight tubular structure and is complete with a mouth and anus. It
also shows regional differentiation into parts like buccal cavity, pharynx, oesophagus, gizzard, intestine and rectum. ’
The digestive system shows segmental specialisation.
8. Annelids are the first group having blood vascular system. A definite circulatory system
or blood vascular system is present which consists of blood and blood vessels. Blood flows only in definite blood vessels, hence the circulatory system is described as ‘closed type’ of circulatory system. Blood is red in colour due to the presence of haemoglobin in the plasma, *
9. Respiration occurs by simple diffusion through the body surface or through respiratory
structures called gills.
10. Excretory system consists of coiled ectodermal tubes called nephridia, though which excretion takes place.
11. The nervous system is well developed consisting of a nerve ring and a double ventral nerve cord.
12. Characteristic locomotory structures are usually present, either in the form of chitinOus setae or fleshly lateral extensions called parapodia.
13. Reproduction is usually by sexual mode. Members may be either bisexual or unisexual.
14. Development may be direct or indirect, where the larval stage present is represented by a trochophore larva.

Classification: .
The phylum Annelida is divided into 3 classes:-
1. Class : Polychaeta : (Poly : many ; chaeta : hair) eg : Nereis.
2. Class : Oligochaeta : (Oligo: few ; chaeta: bristles) eg. : Earthworm.
3. Class : Hirudinea : eg: Hirudinaria granulosa (Indian cattle leech), Hirudo medicinales (British medicinal leech).

Phylum Arthropoda:

The phylum Arthropoda is the largest phylum of the animal kingdom. It includes more than 80% of all. the known animals. They are found in marine, terrestrial and aerial habitats. They are the only major invertebrates adapted to live on dry land. Insects among arthropods are the only invertebrates capable of flight. More than about 10,00,000 species of arthropods have been described so far.

General characters:
1. Arthropods are bilaterally symmetrical, triploblastic, metamerically segmented and eucoelomates.
2. Segmentation of the body is less apparent and the number of segments is fewer in number.
3. They show the highest degree of cephalisation, that is formation of a well developed head.
Head is usually formed by the fusion of six body segments. Following the head region is the trunk which is usually divisible into an anterior thorax and a posterior abdomen.
4. Their body segment usually bears paired lateral and jointed appendages. A segment of the appendage is known as podomere. The appendages are variously modified in different groups and even in different parts of the same animal.
A few appendages close to the mouth are modified into jaws and are helpful in feeding. A few appendages are sensory in function .
Some appendages helpjri locomotion. Due to the presence of jointed appendages or legs for locomotion, the phylum gets the name Arthropoda, which means jointed feet.
5. Their body is covered externally by an exoskeleton made up of chitinous cuticle. In each segment, the chitinous cuticle forms a dorsal convex tergum, a ventral sternum and two lateral pleura.
6. The exoskeleton is periodically cast off, and regrown at regular intervals. This is redundant. This periodic casting off of the exoskeleton is known as ecdysis or moulting.
The presence of chitinous exoskeleton does not permit free growth of the animal, to over come this problem, the exoskeleton is periodically cast off.
The stages between the series of moults are called instars. The animal grows during intervals between successive moults.
7. Muscles are present, which are segmentally arranged in bundles.
8. The body cavity is filed with blood and such a cavity or coelom is known as a hemocoel.
The hemocoel doesn’t bear the lining of coelomic epithelium.. The true coelom is reduced and is confined to the spaces of excretory and genital organs. ,
9. The digestive system is well developed and is complete with a mouth and a posterior anus. Mouth parts trophi surrounding the mouth are used in feeding.
10. The circulatory system is of open type, where the blood flows through a system of ill defined channels or sinuses. The various organs are indeed bathed in blood. Hemocoel is a part of open circulatory system. A dorsal pulsatile heart is present.

1st PUC Biology Question Bank Chapter 4 Animal Kingdom

11. Respiration is either through body surface through gills or through trachea or book lungs.
12. Excretion takes place through green glands [coelomic duct] or by malpighian tubules. The nitrogenous waste products are excreted “4n the form of uric acid.
13. Nervous system consists of paired dorsal cerebral ganglia forming brain and a double ventral nerve cord with segmental ganglia.
14. Sense organs comprise of simple eyes or compound eyes with mosaic vision, chemoreceptors and tactile sense organs.
15. In some forms, the endocrine glands are well developed. Even moulting is under the control of a hormone called ecdysone, secreted by the endocrine glands.
16. Sexes are usually separate and a few exhibit sexual dimorphism. Fertilised eggs are yolky enclosed in a shell. Fertilisation is generally internal.
17. Development may be direct or indirect. When indirect, the larval forms undergo varying degrees of metamorphosis to become adult ones.
18. Majority of the forms are oviparous.

Classifications:
Phylum Arthropods is divided into the following classes:-
1. Class: Crustacea: [crusta – hard shell], eg: Prawn, lobsters, crab etc.
2. Class: Insects or Hexapoda [Insecterm – cut into], eg: Butterfly, honey bee etc.
3. Class: Diplopoda [Diplos – double, podos – feet], eg: Julus (millipede).
4. Class: Chilopoda. eg: Centipede.
5. Class: Arachnids, eg: Scorpion, spider etc.
6. Class: Onychophora. eg: Peripatus.

Phylum Mollusca:

The phylum mollusca includes a wide variety of with unsegmented animals soft bodies. The phylum includes about 1,00,000 species and is the second largest phylum. Nearly half of the species are now extinct.
General characters:-
1. Members are mostly aquatic either marine or fresh water forms. A few are amphibious,
and some are terrestrial.
2. Mollusca are bilaterally symmetrical, triploblastic, unsegmented and soft bodied, eucolemate animals.
3. The body consists of a head, foot, visceral mass, and a mantle.
4. The head bears eyes, tentacles, and other simple sense organs.
5. The foot is ventral. It is thick, muscular, and locomotor in function. ’
6. The body is covered by a thick fold of skin called mantle or pallium which arises from the
body wall. Mantle encloses a triangle mantle cavity which houses the gills, nephridiophores, gonopores and anus.
7. Most molluscs possess a shell which is secreted by the mantle. It is made up of CaCO3.
The shell may be external, internal totally absent or may be reduced in size. The shell may be of various sizes, shapes, and colours. It protects the soft inner body.
8. The coelom is reduced, and is confined to the cavities surrounding the heart, kidneys, gonads, and parts of intestine.
9. The digestive system is complete, and in a few forms, a grasping organ called radula is
present in the buccal cavity. Usually a digestive gland (hepato pancreas) is associated with the digestive system.
10. Respiration takes place through mantle, and ctenidia (gills) in aquatic forms, and through pulmonary chamber (primitive lung) in terrestrial forms.
11. The circulatory system is of open type (except in cephalopods), and consists of a heart, and an elaborate system of ill defined channels or sinuses forming haemocoel.
12. Excretion takes place through one or two pairs of metanephridia.
13. The nervous system consists of pairs of ganglia is a sense connected by commissures.
14. Sense organs include eyes, statocysts (organs of equilibrium), chemoreceptors (osphradia) and tentacles.
15. Most of the members are: dioecious (unisexual), and some are monoecious (bisexual).
Fertilisation may be internal or external.
16. Development is direct or indirect with larval stages,
(a) Glochidium larvae.
(a) Trochophore larva, and Veliger larva.

Classifications:-
1. Class: Monoplacophora
eg: Neopalina galatheca.
2. Class: Amphineura
eg: Chiton, Chaetaderma.
3. Class: Scaphopoda
eg: Dentalium (Elephant tusk shell).
4. Class: Gastropoda .
eg: Pila (Apple snail), Patella, Turbo Helix.
5. Class Pelecypoda (Bivalvia)
eg: Unio (mussel), Oyster, Mytilus.
6. Class: Cephalopoda .
eg: Octopus (Devil fish), Sepia (Cuttle fish).

1st PUC Biology Question Bank Chapter 4 Animal Kingdom

Phylum Echinodermata:

Echinodermata comprises of animals with a spiny skin. About 6000 species of echinoderms have been described.

General characters:-
1. They are exclusively marine.
2. Echinoderms are rounded, cylindrical or star shaped , organisms.
3. The body is triploblastic, eucoelomate, and unsegmented with radial symmetry. (But larvae are bilaterally symmetrical).
4. Body is generally covered by skin or exoskeleton supported by an endoskeleton made up of calcareous plates/ossicles. From these plates spines may arise which project through the epidermis (skin).
5. Head is absent, and the body is distinguishable into oral, and aboral surfaces.
6. Coelom is extensive, enterocoelous filled with coelomic fluid, and amoebocytes.
7. They possess a characteristic Ambulacral or water vascular system.
It consists of a system of tubes which emerge as a series of pouch like projections from the body surface as body appendages / podia / tube feet, and help in locomotion, food capture, and respiration.
8. Alimentary canal (Digestive system) is complete with mouth on the oral surface and anus
on an aboral surface.
9. Circulatory system is primitive, and reduced. It is haemal, lacular or coelomic channels. (Thus- it is an open type of circulatory system).
10. Respiration may be by minute gills called dermal branchiae or papullae (star-fishes) or by
tube feet, or by genital bursae (brittle star) or by peristomial gills (sea urchin) or by cloacal respiratory trees (cucumaria).
11. Excretory system is absent. Excretory product is ammonia, which is eliminated by amoebocytes of the coelomic fluid.
12. Nervous system is primitive, and consists of 3 nerve rings, and radial nerves.
13. Sensory system is poorly developed. It comprises of simple eyes, and chemoreceptors.
14. Sexes are separate with large gonads, and simple ducts.
15. Fertilisation is external.
16. Development is indirect with free swimming ciliated larval stages.
17. Regeneration of lost parts takes place.
18. They exhibit autotomy i.e., self amputation of body parts to escape from enemy.

1st PUC Biology Question Bank Chapter 4 Animal Kingdom

Classification:
The phylum Echinodermata is divided into two sub phyla.
1. Pelmetazoa – Echinoderms attached through out or part of their life to a substratum by means of a stalk.
2. Eleutherozoa – Devoid of stalk, and are free living forms.
Sub phylum Pelmetazoa comprises of only one class, namely Crinoidea.
eg: Antedon (sea lily), Pentacrinus

Sub phylum Eleutherozoa comprises of 4 classes:-
1. Class: Asteroidea. eg: Asterias (Star fish), Astropecten (Sea star), Solastar.
2. Class: Ophuroidea. eg: Ophiothrix (Brittle star), Ophioderma.
3. Class: Echinoidea. eg: Echinocardium (Heart urchin) Salmacis (Sea urchin).
4. Class: Holothuroidea. eg: Cucumaria, Holothuria (Sea cucumber).

Phylum Hemichordata:

General characters:-
1. This phylum connects invertebrates with chordates. Earlier it was considered as a subphylum under phylum chordata.
2. It consists of wormlike marine animals.
3. They possess an organ system level of body organisation.
4. Organisms are bilaterally symmetrical, triploblastic and coelomate animals.
5. Animal body is cylindrical, and composed of anterior proboscis, a collar and a long trunk.
6. Nutrition is holozoic. Digestive system is complete.
7. Circulatory system is of open type.
8. Respiration takes plaqe through glands.
9. Sexes are separate. Fertilisation is external. Development is indirect, eg: Balanoglossus and Saccoglossus.

Phylum Chordata:

The Phylum Chordata comprises of animals with amazing diversity of habits, form and structure. It includes protochoirdates and vertebrates. There are more than 60,000 species of animals under this phylum.
Characteristics of Chordates:
The chordates are distinguished from all other nonchordates by the following three diagnostic characters:
(1) Presence of Notochord (or Chorda dorsalis): This is a dorsal skeleton rod, which is present either in the embryo, in larva or in the adult stage. It is located above the alimentary canal, and below the dorsal tubular nerve cord.
(2) Presence of a dorsal hollow nerve cord: This occurs in all chordates either in the embryonic, larval or adult stages. It is situated along the mid dorsal line, above the notochord.
(3) Presence of pharyngeal clefts (or gill clefts or visceral clefts or gill slits): The gill slits are paired openings through the lateral wall of the phyarynx, leading from the pharynx to the exterior.

1st PUC Biology Question Bank Chapter 4 Animal Kingdom

Characters:
The chordate characteristics which are common with non-chordates are as follows:
(1) Triploblastic condition.
(2) Presence of a coleom.
(3) Bilateral symmetry.
(4) Metamerism.
(5) Cephalization.
(6) A living endoskeleton.
(7) A’post – anal tail.
(8) Only two paired appendages.
(9) A closed circulatory system.

Classification:
The large phylum chordata is divided into two groups as follows:
Group 1:Acrania or Protochordates: This includes: lower chordates or prevertebrates which lack cranium or skull. This group is divided into two sub-phyla as follows:
Subphylum 1:
UroChordata or Tunicata: This includes marine, solitary and colonial tunicates, whose body is enclosed within a cellulose tunic or test Nerver cord are confined to the tail in the free swimming larva. Example: Herdmania.
Subphylum 2: Cephalochordata.
This includes lancelets, Marine, fish-like, burrowing animals with segmented body muscles. Notocord extends to the tip of the snout and persists throughout life. Ciliary filter feeder. Example: Amphioxiis.
Subphylum 3: Vertebrata (or Craniata): These are vertebrates with definite head and trunk, supported by a series of cartilaginous or bony skeletal structures called vertebrae.

Classification.
The subphylum vertebrata is divided into two divisions: Agnatha, and Gnathostomata. Division 1: Agnatha: This includes the earliest fish-like vertebrates without jaws, paired apendages and with a single median nostril.
Class 1: Cyclostomata: This includes lamprey eels and hag-fishes, having jawless circular mouth and round gill pouches.
Examples: Petromyzon.
Division II: Gnathostomata: This includes advance vertebrates possessing a pair of true jaws, paired nostrils and paired appendages. It comprises of two superclasses: Pisces and Tetrapoda. –
Super class l:Pisces (Fishes): This comprises two living classes: Chondrichthyes and Osteichthyes.
Super class II : Tetrapoda: This comprises of four classes : Amphibia, Reptilia, Aves and Mammalia.

Super Class : Pisces

This super class includes the fishes, which are exclusively aquatic vertebrates. About 30,000 species of fishes are known so far.
1. Fishes are exclusively aquatic, either freshwater or marine.
2. They are poikilotherms (i.e. cold blooded animals).
3. The body is generally streamlined or spindle shaped but in some it is elongated and snake like. A few have dorsoventrally flattened ones.
4. Appendages in the form of paired and unpaired fins, are seen which are supported by cartilagnous or bony fin rays.

1st PUC Biology Question Bank Chapter 4 Animal Kingdom

5. Usually dorsal, caudal and anal fins are unpaired, while the pectoral and pelvic ones are paired.
6. Tail is muscular, and used for propulsion.
7. An exoskeleton of dermal scales is always present.
8. Body is- usually divided into head, trunk, and tail.
9. Eyes – one pair with movable eyelids, and nictitating membrane.
10. Nostrils are-paired but do not open into pharynx. They are olfactory in function.
11. Lateral line sense organs are seal.
12. Organs of respiration are gills (but accessory respiratory organs might be seen).
13. Gill slits are usually less than 7 pairs (usually 4 or 5).
14. Alimentary canal is specialized with a distinct stomach, and a well defined pancreas.
15. Heart is two chambered with an auricle, and a ventricle. The heart is a venous, since it receives and pumps only the deoxygenated blood.
16. Excretory organs are in the form of paired mesonephron kidneys.
17. Nervous system comprises of brain, and 10 pair of cranial nerves.
18. Sexes are separate, and development may be direct or indirect, and gonads are usually paired.
19. Eggs are not protected by calcareous shells. Therefore they are non cleidoic, and cannot be laid on land.

Pisces are divided into two classes:
1. Chondrichthyes (cartilaginous fishes).
2. Osteichthyes (bony fishes).

Chondrichthyes Osteichthyes
• Skeleton is made up of cartilage. • Skeleton is made up of bones.
• Exclusively marine. • Both marine and fresh water forms are seen.
• They possess placoid scales. • Possess cycloid or ctenoid scales.
• Mouth and nostrils are situated on ventral side of the body. • Mouth and nostril are terminal in their position.
• Passes 5 pairs of gill slits. • Possess 4 pairs of. gill slits which are covered by operculum.
• Tail is heterocercal. • Tail is homocercal.
• Devoid of air bladders. • Possess air bladders.
• Males usually possess a pair of claspers.
eg: Scliodon (Shark)
Narcine (Electric ray)
Trygon (Sting ray).
• Claspers are absent.
eg: Anguilla (Fresh water Eel)
Clarias (Cat fish)
Hippocampus (Sea horse).

Super Class : Tetrapoda
Class Amphibia:

The class amphibian (“amphi-both” bian-life) includes cold blooded vertebrates adapted to both land and water, as such they have made a “compromise between the two environments”.
1. Amphibians are cold blooded (poikilotherms) aquatic or terrestrial vertebrates with limbs, and lungs.
2. Body is divided into head, and trunk (but in few forms it is divided into head, neck, trunk, and tail).
3. The skin is smooth without scales, and is always moist (due to the presence of glands). It is highly vascularised, thus cutaneous respiration is seen in an amphibian.
4. The paired fins of fishes are modified into limbs in amphibia. Two pairs of limbs (fore limbs, and hind limbs) are present which are pentadactyl.
5. At the head region a pair of eyes, a pair of external nostrils, mouth and a pair of eardrums are present.
6. Mouth is provided with teeth on one or both the jaws, and a movable tongue.
7. Eyes are often provided with a well-developed nictitating membrane.
8. Amphibians are devoid of exoskeleton, but they possess a large bony endoskeleton.
9. Digestive system is well developed.
10. Respiration is by gills, book lungs and skin or by the lining of the buccal cavity.
11. The circulatory system comprises of a three – chambered heart and veins. Heart has double circulation (i.e, system and pulmonary circulation) RBC are oval, biconcave and nucleated.

1st PUC Biology Question Bank Chapter 4 Animal Kingdom

12. The nervous system has a brain and a pair of cranial nerves.
13. Excretory system, and reproductive system are associative to form a urinogenital system. The excretory system consists of a pair of mesonephric kidneys, and a large urinary bladder. Presence of cloacae into which digestive, excretory and reproductive system sopen out, through the eloacal aperture.
14. Sexes are separate. Reproductive system comprises of paired gonads and gono ducts. Majority of them are oviparous and the eggs are noncleidoic. Fertilization is external.
15. Development is indirect. Larva is called tadpole.

Note 1: During indirect development metamorphosis takes place.
Note 2: Pedogenesis is seen in a few members like ambylystoma, where development of ova into a young one takes place.
e g: Limbless amphibians – Ichthyophis.
Tailed amphibians – Salamander, Newts and Necturus.
Tailless amphibians – Frogs, Toads (Bufo, Rana, Hyla).

Class Reptilia:

Reptilians were the dominant group of vertebrates during the Mesozoic period which was known as the ‘golden age of reptiles’. They are the first group of vertebrates to have developed completely for land life (terrestrial life).
1. Reptiles are poikilothermic (cold blooded) animals, which are completely adapted for terrestrial mode of life, but some have secondarily adapted for aquatic mode of life.
2. Body is usually divisible into head, neck, trunk and tail.
3. The skin is dry, and covered by hard, homy, epidermal scales or scutes, which protect the animal from desiccation and from predators. The epidermal scales from a sort of exoskeleton to the dry skin. Skin is devoid of skin glands.
4. The head region possesses a mouth guarded by jaws with teeth, a pair of compound eyes, a pair of external nares and a pair of external ears (tympanic membrane). In snakes the tympanic membrane is poorly developed,
5. Trunk region possesses two pairs of pentadactyl limbs, whose digits terminate with horny claws.
6. The endoskeleton is bony.
7. Digestive system is complete and it is associated with digestive glands (pancreas and liver).
8. Respiration is pulmonary. Respiratory system comprises of external nostrils, internal nares, pharynx and lungs. Gills are absent.
9. Circulatory system includes a 3 – chambered heart (4 chambered heart In crocodiles), and Mood vessels. It is a closed type circulatory system.
10. Unnogenital system comprises of paired metanephric kidneys which excrete nitrogenous waste in the form of uric acid.
11. Sexes are separate. Gonads are paired, Males have either single or double copulatory organs. Fertilization is internal. Most of the forms are oviparous, while a few are ovoviviparous.
12. Fertilized egg is cleidoic and is laid on land.
13. Development is direct.
14. Nervous system comprises of a brain, 12 pairs of cranial nerves and a peripheral nervous system.
eg: Garden lizard (calotes)
Wall lizard (gecko)
Flying lizard (Draco)
Chameleon
Snakes – Cobra, Krait, Viper etc.,

1st PUC Biology Question Bank Chapter 4 Animal Kingdom

Class Aves:

Birds (Aves) are warm-blooded vertebrates with a constant body temperature, and with an exoskeleton of feathers. Feathers are nothing but completely modified epidermal scales (of reptiles). Aves resemble reptiles, and at the same time, they are extremely modified, and superior to them. Hence birds are also known as “Glorified Reptiles”.
1. Birds are homeothermic (warm blooded) animals.
2. Body is boat shaped and is adapted in such a way as to offer the least resistance while flying.
3. Body is differentiated into a head, long neck, a trunk and a short tail.
4. Body is covered by feathers, which provide insulation.
5. Forelimbs are modified into wings for flight. Wings are provided with feathers, which are bad conductors of heat.
6. The hind limbs are shifted forwards to balance the body while walking. They are variously modified for perching, walking, running, swimming etc.,
7. Hind limbs have 4 toes, and are covered with epidermal scales.
8. Endoskeleton is fully ossified (bony). Bones are tubular and hollow fond have air cavities or air sacs (pneumatic bones).
9. Bones of the skull are fused. ,
10. Jaws are devoid of teeth but covered by homy sheaths and are modified to form a beak.
11. Beak is variously modified to suit the individual food habits.
12. Vertebrae of the neck region are usuallyheterocoelous.
13. Ribs are small, and are fused to form a composite bony plate called the synsacrum (14 vertebrae fuse).
14. The last few caudal vertebrae fuse, to form the pygostyle.
15. Digestive system is complete.
16. Respiration takes place with the help of lungs, which are spongy.
17. There is a voice box or syrinx near the junction of trachea and bronchi, which is responsible for the production of sound.
18. Nervous system is well developed with 12 pairs of cranial naves.
19. Heart is completely four chambered. There is a separation of pure and impure blood, RBC are nucleated.
20. There a pair of metanephric kidneys. There is no urinary bladder. Aves excrete nitrogenous wastes in the form of uric acid.
21. Sexes are separate, testes are paired. In female only the left ovary, and oviduct is present.
22. Fertilization is internal.
23. Eggs are large, and contain a large amount of yolk. Eggs are chleidoic.
24. Development is direct.
25. During development, embryos are surrounded by amnion, allantois, yolk sac, and chorion
(extra embryonic membranes).
eg: Flightless birds – Kiwi, Penguin, Emus and Ostriches.
Capable of flight – Stork bird. Swans, Goose and Ducks.

1st PUC Biology Question Bank Chapter 4 Animal Kingdom

Class Mammalia:

1. Class Mammalia includes warm blooded and highly organized animals possessing mammary (milk glands for suckling their young ones. They live almost in all the environments of the world, and undergo secondary adaptation to suit their habitats. They are also known as hair quadrupeds.
2. Mammals are all homoeothermic (warm blooded) animals.
3. The body shape varies, and it is covered by hairs.
4. Body is divisible into head, neck, trunk and tail.
5. Skin is glandular and includes sebaceous, and sweat glands in both the sexes, and mammary glands in the females.
6. Head region possesses a pair of eyes protected by eyelids and eyelashes, a pair of external ears or pinnae, and a pair of external nares.
7. They possess two pairs of pentadactyl legs, which are variously modified to perform different functions [like walking, running, climbing, swimming, burrowing and flying. Digits bear homy claws, nails or hoofs.
8. Teeth are placed in sockets [Thecodont]. Teeth are heterodont [different types of teeth
i. e, all are not of the same morphology], and diphyodont’ [i.e, 2 sets of teeth milk teeth and permanent teeth].
9. There is well-developed voice apparatus, the larynx.
10. There is a muscular diaphragm separating the thorax, and abdomen.
11. Respiration is by lungs.
12. Circulatory system consists of a four- chambered heart, which maintains complete double circulation. RBC’s are non-nucleated.
13. Nervous system is well developed. Brain consists of a large cerebrum, cerebellum, and cerebral cortex. There are 12 pairs of cranial nerves.
14. Excretory organs comprise of a pair of metanephric bean shaped kidneys and a coronary bladder. Nitrogenous water products are excreted in the form of urea (present in urine fluid).
15. Sexes are separate, and sexual dimorphism is seen.
16. Fertilization is internal.
17. Majority are viviparous. Viviparity is common except in the egg laying mammal called platypus.
eg: Lion, Tiger, Cat, Dog.

1st PUC Biology Question Bank with Answers

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