Assertion: From an evolutionary point of view,the human gestation period is believed to be shortening.
Reason: One major evolutionary trend in humans has been the larger head undergoing a relatively faster growth rate in the foetal stage.

Scientists believe that evolution is gradual. However,extinction,which is a part of the evolutionary story,is often 'sudden' and 'abrupt' and also group-specific. Comment on whether a natural disaster can be the cause of the extinction of species.

Match the following columns:

List-$I$	List-$II$
$(a)$ Hugo de Vries	$(i)$ Natural Selection
$(b)$ Hardy-Weinberg	$(ii)$ Saltation
$(c)$ Darwin	$(iii)$ $(p+q)^2 = 1$
$(d)$ Lamarck	$(iv)$ Acquired Characters

Which two geographical regions are separated by high mountains?

Given below are four statements $(A-D)$ each with one or two blanks. Select the option which correctly fills up the blanks in two statements.
Statements:
$(A)$ Wings of butterfly and birds look alike and are the results of $ . . . . . . (i) . . . . . . $ evolution.
$(B)$ Miller showed that $CH_4, H_2, NH_3$ and $ . . . . . . (i) . . . . . . $ when exposed to electric discharge in a flask resulted in formation of $ . . . . . . (ii) . . . . . . $.
$(C)$ Vermiform appendix is a $ . . . . . . (i) . . . . . . $ organ and an $ . . . . . . (ii) . . . . . . $ evidence of evolution.
$(D)$ According to Darwin,evolution took place due to $ . . . . . . (i) . . . . . . $ and $ . . . . . . (ii) . . . . . . $ of the fittest.

The evolutionary history of a particular group of organisms is called