Question

Match List I with List II and select the correct option.

List I	List II
A. Darwin	I. Mutation theory
B. Hugo de Vries	II. Theory of inheritance of acquired characters
C. Lamarck	III. Natural selection theory

• A. A - I, B - III, C- II
• B. A - II, B - I, C- III
• C. A - III, B - I, C- II
• D. A - III, B - II, C- I

Answer 1

The correct option is C A - III, B - I, C- II

Hugo de Vries, based on his work on Oenothera lamarckiana or evening primrose, proposed the mutation theory. In this theory he explained that new species evolve by sudden and distinct heritable changes called mutations.

These mutations can occur at any time, hence are random and can be useful, harmful or have no effects at all on the organisms, hence are directionless. As the mutations are produced occasionally without prior precedent, they are termed as discontinuous heritable changes in the genetic material that result in the expression of observable characters which are extremely different from each other without having any intermediate form.

On the other hand, Darwin’s theory of natural selection states that new variations appear in every generation. Such small variations accumulate over several generations by natural selection until the offspring become significantly different, thus evolving into a new species. Thus, Darwinian variations were considered directional.

Lamarck, a French biologist, believed that new characters are acquired by the organisms in order to adapt to the changes in the environment. The changes in the environment of an organism creates new needs in behaviour or structure in the organism that would help it to adapt better to the changing environment. This leads to the development of new characters which involve the greater use of some organs keeping it functional while disuse of certain organs leads to their size reduction and loss of functionality.