The Punnett square for a sex-linked trait is shown. Xr is the recessive allele. Based on the Punnett square, which statement is true? Xr X
X XrX XX
Y XrY XY
A.
Female offspring have a 50 percent chance of expressing the recessive trait.
B.
Both male offspring will express the recessive trait.
C.
Both female offspring will express the recessive trait.
D.
There’s a 50 percent chance the male offspring will express the recessive trait.

Ry was studying two populations of the same species of lizards. one population lived on an island and the other lived on the mainland. both populations were affected by a hurricane that hit the island and the mainland with equal force. a year later, henry was testing the gene frequency and saw a decrease in genetic variation in the island species, but not in the mainland species. which best describes a conclusion he might have reached? gene flow greatly affects small populations, but large populations can recover. genetic drift greatly affects small populations, but large populations can recover. gene flow greatly affects large populations, but small populations can recover. genetic drift greatly affects large populations, but small populations can recover.

When does the circulatory system work with the respiratory system? a. during blood cell formation b. during cellular respiration c. during intestinal digestion d. during a viral infection

Which of the following explains why a tree is often used as a model to represent the principle of common descent