Most scientific investigations use some form of the scientific method. Find out more about the scientific method. Science as defined above is sometimes called pure science to differentiate it from applied science, which is the application of research to human needs.
There are 13 chromosomes in a frog gamete and 26 in a frog body cell.
Here, females carry two X chromosomes (XX) and only produce gametes with X chromosomes. Males, on the other hand, carry only one X chromosome (XO) and produce some gametes with X chromosomes and some gametes with no sex chromosomes at all (Figure 5). Figure 5: Sex determination in insects.