"The chromosome number of the sexually reproducing parents and their offspring is the same." Justify this statement.

Which of the following pairs of organs are $NOT$ homologous organs?

Study the following cross and the self-pollination in $F_1$. Fill in the blank and answer the question that follows:
Parents: $RRYY \times rryy$
(Round,yellow) (Wrinkled,green)
$F_1$: $RrYy \times$ ?
(Round,yellow)
What are the combinations of characters in the $F_2$ progeny? What are their ratios?

What is micro-evolution? Does it explain speciation?

$(a)$ When a pesticide is sprayed on a population of insects,all insects do not get killed but few of them survive. Give reason.
$(b)$ When is a recessive trait capable of expressing itself? Write its expression with respect to the height of a plant (genotype).

Select the incorrect statement.