The basic function of the kidneys is to filter waste products from the blood plasma and secrete them as urine. It accomplishes this via three main processes that occur in a structure known as the nephron. In , plasma filters from the capillaries into Bowman's capsule of the nephron. This is the first step in urine formation. In , excess waste substances not secreted into Bowman's capsule move from the capillary plasma into the tubules. In , substances of value move from the tubules back into the capillary plasma.

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