Which of the following pairs is $wrongly$ matched?

Genes that are similar in phenotypic effect when present separately,but together interact to produce a different trait and the ratio is $9:7$ in the $F_2$ generation. What are such genes known as?

Variation refers to .......

Match the following pairs based on the sex determination mechanism shown in the table:

	Male $(♂)$	Female $(♀)$
$x$	$XY$	$XX$
$y$	$ZZ$	$ZW$

Which of the following statements are false?
$I.$ $A$ dominant allele determines the phenotype when paired with a recessive allele.
$II.$ $A$ recessive allele is weaker than a dominant allele.
$III.$ $A$ recessive allele does not show its effects when paired with a dominant allele.
$IV.$ $A$ dominant allele is always better for an organism.

The number of chromosomes present in a gorilla is: