NEET Practice Questions (MCQs) with Answers & Solutions

According to Hardy- Weinberg equation,

P² + 2PQ + Q² = 1

Where P = dominant allele frequency

          Q = Recessive allele frequency

          P² = Homozygous dominant genotype

          2PQ = Heterozygous genotype 

          Q² = Homozygous recessive genotype 

here p = 0.6 and Q= 0.4

therefore, 2PQ = 2 $\times$ 0.6 $\times$ 0.4 = 0.48

(b) Speciation of sympatric species is the formation of species within a single population without geographic isolation. Thus the subpopulation becomes reproductive isolated in the midst of its parent population.

Flame cells are the excretory organs in member of phylum-Platyhelminthes. Which are commonly called as helminths and Malpighian tubules are the excretory organs in member of phylum-Arthropda along with other insect.

Tendrils in plants are an example of divergent evolution because tendril is a modified axillary branch which modifies itself to support the plant. 

Nucleic acids (DNA and RNA) rich in carbon, hydrogen, oxygen, nitrogen and phosphorus are only capable of reproduction at their own, therefore considered as basic of life.

Mutations were referred to as 'Saltations' or sports by Hugo de Vries. Therefore, theory of mutation is also called 'theory of saltation'.

(d) According to Hardy-Weinberg equilibrium, the balance in the relative numbers of alleles that is maintained within a large population over a period of time assuming that; mating is random, there is no natural selection, there is no migration, there is no mutation.

Hardy-Weinberg equation is

             p² + 2pq + q² = 1

Vestigial organs are present in an organism in a diminished size but are no longer useful.

The two critical steps in the evolution of humans were the evolution of bipedalism (walking on two feet) and the enlargement of the brain. The earliest hominoid and the direct ancestors of humans belong to the genus-Australopithecus.

NCERT page number 127,Para-1

7.1 Origin of Life