Which of the following hormones is responsible for both contraction of the uterus and milk production in lactating women?

A. Oogenesis is the process of egg cell (ovum) formation in females and is responsible for producing gametes, not somatic cells.

B. Spermatogenesis is the process of sperm cell formation in males, also producing gametes, not somatic cells.

C. Mitosis is the process that produces somatic cells. It is a type of cell division that results in two genetically identical daughter cells, each with the same number of chromosomes as the parent cell. Somatic cells are all body cells except for gametes.

D. Meiosis is the process that forms gametes (sperm and eggs), reducing the chromosome number by half to ensure sexual reproduction results in a normal chromosome count. It does not form somatic cells.

A. In a hypertonic solution, water moves out of the cell into the surrounding fluid, causing the cell to shrink. Therefore, the volume of the cell does not increase.

B. A hypertonic solution has a higher concentration of solutes than the inside of the red blood cell. As a result, water moves out of the cell, causing it to shrink or decrease in volume.

C. The permeability of the cell membrane is not directly affected by the tonicity of the solution. The change in cell volume is due to the movement of water, not a change in membrane permeability.

D. The permeability of the cell membrane is not typically affected by a hypertonic solution, but rather the osmotic pressure that drives water movement across the membrane. The main effect is on the cell's volume, not its membrane permeability.