Sickle cell anemia is known to run in a family. A pedigree chart for this family is shown below. The parents are shown at the top and from left to right appear as a half-shaded circle next to a half shaded square. The two are connected by a straight line. Below the parent pair is a vertical straight line connecting the next row of circles and squares which are the offspring. Starting from the left an unshaded square, half-shaded circle, another half-shaded circle and a completely shaded square are shown. All these are also connected by a horizontal straight line. What percentage of the offspring have sickle cell anemia? 0% 25% 50% 100%

25%

Explanation:

From the description;

The parents: half shaded circle and square = heterozygous parents

The offspring:

unshaded square = homozygous normal

half shaded circle = heterozygous normal

half shaded circle = heterozygous normal

completely shaded square = affected (homozygous abnormal)

The unshaded and half shaded offspring are normal and do not have sickle cell anemia. The completely shaded square represents a male offspring with sickle cell anemia.

Out of 4 offspring, 1 is affected for sickle cell anemia. Hence the percentage of the offspring that have sickle cell anemia is 25%.

answer:   option a) glucagon was secreted by his pancreas before he ate the cookies because blood glucose was low. insulin was secreted after he ate the cookies because his blood glucose was high.

explanation: