The number of pair$(s)$ of sex chromosomes in the zygote of humans is

Name any five vegetables generated from a common ancestor through artificial selection rather than natural selection. Also,mention the features for which each vegetable is selected.

$A$ child who inherits an $Y$-chromosome from her father will be a girl.

An individual can pass on to its progeny the experiences of its lifetime.

$A$ woman having blood group $B$ marries a man having blood group $A$ and they have four offspring. Two children have blood group $O$,one has blood group $B$,and one has blood group $AB$. Now,answer the following:
$(i)$ Which blood group is dominant?
$(ii)$ Which blood group is recessive?
$(iii)$ What are the genotypes of the parents?
$(iv)$ Show the possible genotypes and phenotypes of the offspring.

With the help of suitable examples,explain why certain traits cannot be passed on to the next generation. What are such traits called?