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

Select the statements that describe characteristics of genes

i. genes are specific sequence of bases in a DNA molecule

ii. a gene does not code for proteins

iii. in individuals of a given species, a specific gene is located on a particular chromosome

iv. each chromosome has only one gene

In peas, a pure tall plant (TT) is crossed with a short plant (tt). The ratio of pure tall plants to short plants in F2 is

The theory of evolution of species by natural selection was given by

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