Why is photosynthesis vital for life?

a.

photosynthesis maintain atmospheric levels of oxygen and carbon dioxide.

b.

photosynthesis is a direct means of energy production for many organisms.

c.

photosynthesis is an indirect means of energy production for many organisms.

d.

all of the above

Punnett squares are used to show possible combinations of alleles or to predict the probability of a trait occurring in offspring. an incomplete dominance cross is performed between a bird that is homozygous for red feathers and a bird that is homozygous for blue feathers. purple offspring result. then, two of the purple offspring are crossed. according to the punnett square for this cross, how many of the offspring from the second cross will have a feather color that results from incomplete dominance? 1 in 4 2 in 4 3 in 4 4 in 4