Question 1

Which of the following theories of evolution was proposed by Jean-Baptiste Lamarck?

Accepted Answer

Jean-Baptiste Lamarck proposed the theory of Inheritance of Acquired Characters, also known as Lamarckism. According to this theory, traits acquired by organisms during their lifetime can be passed on to their offspring, driven by a 'internal vital force' and the effects of use and disuse of organs.

Question 2

Who formulated the theory of natural selection independently of Charles Darwin?

Accepted Answer

Alfred Russel Wallace, a naturalist working in the Malay Archipelago, independently arrived at the conclusion of natural selection through the mechanism of survival of the fittest, prompting Darwin to publish his own work.

Question 3

Which of the following pairs of organs are considered homologous?

Accepted Answer

Homologous organs are those that have the same fundamental structure and embryonic origin, but may perform different functions. The forelimbs of a whale and the forelimbs of a human share a common anatomical skeletal plan despite being adapted for swimming and grasping respectively.

Question 4

Wings of butterflies and birds are an example of:

Accepted Answer

Analogous organs are those that have different embryonic origins and internal anatomies, but perform similar functions due to adaptation to similar environmental conditions, representing convergent evolution.

Question 5

Which of the following is an example of a vestigial organ in humans?

Accepted Answer

The vermiform appendix is a narrow, blind-ended tube connected to the cecum, which was functional in herbivorous ancestors for cellulose digestion but is largely reduced and non-functional in humans today.

Evolution — NCERT Class 12 Biology Important Questions & Revision Notes