STD 12 - 7. human health and disease — NEET STD 11 Science — Question

Which one occurs in mollouscs but not in echinoderms

Ensheathing of muscles is called

Choose correct option for given statements :
(i) In a given population frequency of alleles of a gene or a locus is supposed to remain fixed through generations if population present in equilibrium.
(ii) Directional selection known to affect Hardy Weinberg equilibrium.
(iii) If migration occurs by chance, it is called genetic drift.
(iv) Sometimes the change in allele frequency is so different in the new sample of population that they become a different species.
(v) The original drifted population becomes founders of life in a new area and the effect is called founder effect.
(vi) Natural selection can lead to directional if more individuals acquire mean character value of the distribution curve.

When an electric shock is given to the leg of a pithed frog it

Seminiferous tubules open into

Bilaterally symmetrical but acoelomate animal is

The number of floating ribs in human body is