What is the probability percentage of a zygote developing into a male or female offspring in humans?

Some dinosaurs had feathers although they could not fly,but birds have feathers that help them to fly. In the context of evolution,this means that:

$A$ basket of vegetables contains carrot, potato, radish and tomato. Which of them represent the correct homologous structures?

In pea plants, which trait is dominant between height and dwarfness?

The differences observed among individuals are known as...

$A$ guinea pig having black color,when crossed with a guinea pig having the same color,produced $80$ offspring,out of which $60$ were black and $20$ were white. Now,find out:
$(i)$ What is the possible genotype of the guinea pig?
$(ii)$ Which trait is dominant and which trait is recessive?
$(iii)$ What is this cross called,and what is its phenotypic ratio?