What can cause extinction of a species

How does the study of genetic disorders such as pku biologists understand normal alleles?

In a classic experiment using pea shape, mendel conducted two separate genetic crosses. in the first cross the parent plants were “true breeding” for pea shape; one had round peas ( r )and the other had wrinkled (r). the first cross produced a filial 1 generation of all round peas. in the second cross, mendel bred plants from the filial 1 generation. this cross produced different results. out of approximately 1000 plants, about 75% were round and 25% were wrinkled.

Jasmine, at 33 months of age, is able to engage in some self-care behaviors but still has trouble with tasks such as putting on socks. a few months later, she accomplishes this same task relatively easily. the change in abilities is most likely due to