Page 83 - Biology - XII

Body of animal

(a) Man (b) Cheetah (c) Whale (d) Bat

Humerus

Skeletal structure
of limbs Ulna
Radius

Carpals
Metacarpals

Phalanges

Fig. 15.4: Homologous organs in animals

VIVA VOCE

Q1. Is there a purpose behind the study of homologous and analogous organs?
Ans. Yes, the study of these organs give us concrete evidence, supporting evolution process. They also
prove the ability of all the living beings to be able to survive by adaptation and modifi cation.

Q2. Give one example of homology as observed in plants and animals.
Ans. Plants: Thorns of Bougainvillea and tendrils of Cucurbita
Animals: Forelimbs of whales and bats

Q3. Fins of fi sh and fl ippers of whale or seal is homologous or analogous organs?
Ans. Analogous organ

Q4. Give one example of analogous organs each for a plant and an animal.
Ans. Plant: Sweet potato (root modifi cation) and potato (stem modifi cation)
Animal: Flippers of penguins and dolphins.

Q5. Name few organs of diff erent animals which have the same basic structural organisation.
Ans. The forelimbs of frog, lizard, bat, and mammal have similar bones in their forelimbs. These show
little modifi cation in their structures depending on what function they have taken up to perform.

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