Master control genes, or Hox genes affect evolution

A.

by causing mutations in other genes within the genome.

B.

through small changes during embryonic development that lead to different body plans.

C.

through the coevolution of species.

D.

by leading to convergent evolution.

Give an example of a trait that is controlled by more than one gene.

Ivan is looking at a cross section of a stem taken from a vascular plant. he sees two different types of vascular tissue: the xylem, which is closer to the center of the stem, and the phloem, located around the xylem, closer to the outside of the stem. how do these two structures work together in a living plant?

Define the apical impulse and describe its normal location, size, and duration. which abnormal conditions may affect the location of the apical impulse? explain the mechanism producing normal first and second heart sounds. describe the effect of respiration on the heart sounds. describe the characteristics of the first heart sound and its intensity at the apex of the heart and at the base. describe the characteristics of the second heart sound and its intensity at the apex of the heart and at the base.