If a starfish possesses six arms instead of five,what is this an example of?

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

Sex-influenced characters are due to

Differences in twins suggest

Choose the correct sequence of True $(T)$ and False $(F)$ statements:
$(i)$ Queen Elizabeth shows a number of haemophilic descendants.
$(ii)$ Variation in blood group prevalences is due to incomplete dominance.
$(iii)$ Drosophila has three pairs of autosomal chromosomes.
$(iv)$ In birds,the female is heterozygous.

Choose the correct option regarding genetic disorders and inheritance patterns.