With independent assortment, the ratio of phenotypes in the f2 generation of a cross between true-breeding strains (aa bb x aa bb) can be described as 9: 3: 3: 1 when a and b are dominant over a and b. to what phenotype does the "9" in the ratio refer?

a. recessive for both traits
b. dominant for one trait and recessive for the other
c. dominant for the a trait and recessive for the b trait
d. dominant for both traits

What happens when the cell copies its chromosomes

Imagine a self-reactive t cell that has not undergone clonal deletion in the thymus (that is to say, it has escaped central tolerance). if it encounters self antigen in the absence of an infection or inflammation, what will happen to this self-reactive t cell? (select two answers) (a) the t cell undergoes clonal expansion. (b) the t cell gains effector functions. (c) the t cell undergoes apoptosis. (d) the t cell becomes activated. (e) the t cell becomes anergic.

Which is abiotic? a. tree sap b. insect c. sunlight d. wood table