$A$ : $A$ single large mutation called saltation can produce new species.
$R$ : Mutations are directional
Assertion and Reason both are correct and also correct explanation.
Assertion and Reason both are correct but not explanation of assertion.
Assertion is correct, but Reason is incorrect.
Both Assertion and Reason are incorrect.
Assertion : Natural selection is the outcome of difference in survival and reproduction among individuals that show variation in one or more traits.
Reason : Adaptive forms of a given trait tend to become more common; less adaptive ones become less common or disappear.
Match the columns :
Column - $I$ | Column - $II$ |
$(1)$ Mutation | $(a)$ Change in population allele frequencies due to chance alone. |
$(2)$ Gene flow | $(b)$ Difference insurvival and reproduction |
$(3)$ Natural selection | $(c)$ Immigration, emigration change allele frequencies. |
$(4)$ Genetic drift | $(d)$ Source of new alleles. |
How do you express the meaning of words like race, breed, cultivars or variety ?
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 andare the results of ___$(i)$___ evolution.
$(B)$ Miller showed that $CH_4 , H_2 , NH_3$ and ___$(i)$___ when exposed to electric discharge in a flaskresulted in formation of ___$(ii)$___ .
$(C)$ Vermiform appendix is a ___$(i)$___ organ and an ___$(ii)$___ evidence of evolution.
$(D)$ According to Darwin evolution took placedue to ___$(i)$___ and ___$(ii)$___ of the fittest.
Definitions / Explanation : Recapitulation theory or Biogenetic law & Palaeontology