Hybrid vigour is due to

Read all the given statements carefully and determine the number of correct statements.
$(1)$ Mutations are not hereditary.
$(2)$ Male $Drosophila$ flies do not show crossing over.
$(3)$ In honeybees,the male bee is diploid.
$(4)$ In a frame-shift mutation,one nitrogen base is replaced by another nitrogen base at a specific position.
$(5)$ Genes are responsible for inheritance.

When an $F_1$ individual is crossed with either of the two parents,it is known as:

If a modified allele produces a non-functional enzyme or no enzyme,then the phenotype will not be affected in which of the following cases?

Which gene is lethal in maize?

In a dihybrid cross,when one pair of alleles shows incomplete dominance,the resulting genotypic ratio will be ....