Class 11th | Zoology Viva-Voce Question Answers

Q. 1. What are the functions of tentacles in Hydra?

Ans. They help in locomotion and capturing the prey

.

Q.2. What is the significance of moist skin to the

 frog ?

Ans. Moist skin helps in respiration (cutaneous respiration).

Q.3. What is a hermaphrodite animal ?

Ans. The animal that has both male and female sex organs in itself called hermaphrodite animal

Q.4. Why are earth worms called farmer's friend ?

Ans. Because the earth worms plough the soil by making burrows.

Q.5. Give two most important characters of phylum Arthropoda.

Ans. Arthropods have jointed legs and non- living chitinous exoskeleton.

Q.6. Why do frogs undergo hibernation during winters and aestivation during summerss?

Ans. Frog is a cold blooded animal, which does not have constant body temperature. Its body

temperature fluctuates with the environment. Therefore, frog get buried in the soil for hibernatior

during winter and for aestivation during summer.

Q.7. What are metazoan  animals ?

Ans. Multicellular animals are called metazoan animals.

Q.8. Give three most important characteristics of class insecta.

Ans. Insects are invertebrates with jointed legs, have three pairs of legs and body is divisible irn

head, thorax and abdomen.

Q.9. What is pigeon milk ?

Ans. It is a creamy fluid secreted by the crop of female pigeon during the breeding season.

Q.10. What do you mean by compound eye ?

Ans. A compound eye is a group of simple eye called ommatidia.

Q.11. What is the food of earth-worms?

Ans. Soil rich in organic matter.

Q.12. What are three basic characters of chordata?

Ans. (i) Presence of notochord (ii) presence of dorsal hollow nerve cord (ii) presence of paire gill

slits on the sides of pharynx.

Q. 13. What are triploblastic animals?

Ans. Animals developing from three germinal layers i.e., ectoderm, mesoderm and endoder

called triploblastic animals.

Q.14. What is autotomy ?

Ans. On approach of enemy, lizard cuts its tail itself. This is known as autotomy.

Q 15. What is a compound eye?

Ans. Acompound eye is a group of simple eyes (called omatidia,) in which each simple eye forms an image of a part of the object, giving a mosaic vision.

16. Are wings of a bat same as that of bird ?

Ans Wings of a bat are formed of a membrance stretched between the digits of forelimbs while in birds, the forelimbs are completely modified into with no fingers and claws.

Q.17. Bones are hollow in birds. Why?

Ans. Bones are hollow and are filled with air hence the body weight becomes less which is helpful in flying.

Q18. Inspite of poor eye-sight, how are bats able to locate the objects?

Ans. Bats give out ultrasonic sound (waves) by the powerful larynK and muscles. The vibirations are

deflected back after striking an object and are picked up by the ears of bat.The bat can locate rhe object by the time taken by the waves to reach the bat.

Q19. Frogs have webbed hind feet which are longer than fore feet, Why?

Ans. Webbed and longer hind limbs of frogs help in swimming and jumping

Q20. Why is nictitating membrane present in frog?

Ans. Nictitating membrane is a thin membrane which protect the eyes when it is in water.

Q.21 Bow a vertebrate can be distinguished from an invertebrate by external apppearanee?

Ans. Invertebrates do not have backbone, so are soft bodied. Vertebrates have bacebone arnd so are strongly build.

Q.22. Give zoological names of the following animals:                                                                             (a) Earthworm, b) Cockroach

(c) Frog, (d) Rat.

Ans. (a) Pheretima posthuma, (b) Periplaneta americana, (c) Rana tigrina, (d) Rattus rattus

Q23. State difference between the following : (a) Peristomium and Prostomium, (b) Labrum

and Labium, (e) Sternum and Tergum.

Ans. (a) Peristomium is first segment of earthworm where mouth is present and prostomium is the

sensory lobe in front of it. (b) Labrum forms roof of mouth cavity 1ike upper lip. Labium forms

the lower lip (c) Sternum forms dorsal plate the tergum the ventral plate of the segments in

cockroach.

Q24. Name the following : (a) Locomotory organs of earth worm, (b) Pores from which the        

fluid containing sperms comes out, (o) Band of rings used in formation of egg cases

d) A nocturnal insect, (e) The three partas of thorax of cockroach, (f) A gnawing

herbivore.

Ans. a) Setae, (b) Spermiducal aperture, (c) Citellum, (d) Cockroach, (e) Prothorax, mesothoraX,

Detathorax, (f) Rat.

Q.25. How does earth worm keep its body moist ?

Ans. It produces coelomic fluid and mucous from skin to keep body moist

Q.26. What is the role of clitellum is Pheretima posthuma ? On which segments is it

present ?

Ans. Citellum occurs in 14th, 15th, and 16th segtnent and is used in egg case formation as a result o

sexual reproduction.

Q.27. What is the role of spermatheca in earthworm ?

Ans. Spermatheca stores sperms collccted from other earthworm after sexual reproduction.

Q28. Explain the following in a single sentence : (a) Ocillar spot, (b) Hypopharynx

(c) Elytra, (d) Somites, (e) Tympanum, (f) Diastema

Ans (a) Representative of simple eye, (b) Tongue of cockroach, (c) Leathery, protective forewing of

cockroach, (d) Body segments of cockroach, (e) Ear of frog, (f) Gap between the teeth due to

absence of canines and premolars.

Q29What type of head the cockroach has ?Name its mouth parts.

Ans Triangular hanging at rignt angle to body. Mouth parts are: (i) Labrum, (ii) hypopharynx

(iii) mandibles, (iv) maxilla and (v) labium

Q30.How a male cockroach can be distinguished from a female cockroach ?

Ans. Male cockroach has anal styles which are absent in female.