Class 12th Biology 2016 Set2 Delhi Board Paper Solution

Question 26

(a) Differentiate between analogy and homology giving one example each of plant and animal respectively.

(b) How are they considered as an evidence in support of evolution ?

Answer

(a) Homology : Those structure which have similar anatomy but perform different functions shows homology.

Example: Thorns of bougainvilleas and tendrils of cucurbits and forelimbs of whale and bats.

Analogy : Those structure which have similar functions but different anatomy shows analogy .

Example: Eye of octopus and mammals etc. Sweet potato and potato tuber.

(b) These structures are considered as an evidence in support of evolution because:

1) Homology points to development of a similar structure in different directions. So it follows different divergent evolution.

2) Analogy points to different structures evolving for the same function indicating convergent evolution.