Mendel selected garden peas as his experimental material because
(i) Pea plants possess a number of well defined contrasting characters.
(ii) Pea plants contain unisexual flowers.
(iii) Pea plants have perfect bisexual flowers.
 (iv) These are annual plants.

Two species of hen $X$ and $Y$ breed in the month of April and November respectively. They cannot interbreed due to………….

Refer to the given figure. It shows bones of wings of two animals $X$ and $Y$. These wings are $Z$ structures.

Select the option that correctly identifies $X, Y$ and $Z$.

Pure breeding pea plants with green pods are crossed with pure breeding pea plants with yellow pods. All the $F_1$ generation plants have green pods. Plants from the $F_1$ generation are allowed to be interbred. What colour of pods will be observed in $F_2$ generation plants?

The given figure shows undisturbed sedimentary strata at the bottom of an ocean. The fossil found in layer Y resembles the fossil found in layer X. This similarity most likely suggests that