Before intercourse, a woman irrigates her vagina with a solution that lowers the pH of the vaginal fluid to 4.5. What will be the effect on sperm cells in the vagina?

Correct Answer: B

Rationale: The correct answer is B: Rate of movement will decrease. Sperm cells require a slightly alkaline environment to maintain their motility. Lowering the pH to 4.5 will create an acidic environment, causing decreased sperm motility. Choice A is incorrect as lowering pH doesn't affect metabolic rate. Choice C is incorrect because prostaglandin E2 formation is not directly related to pH changes. Choice D is incorrect as oxygen consumption rate of sperm cells is not affected by vaginal pH.

Correct Answer: C

Rationale: The correct answer is C because semen does not contain enzymes that enhance sperm motility. Sperm motility is primarily influenced by the structure and health of the sperm themselves. Semen aids in sperm transport, provides nutrients, buffers the acidic vaginal environment, and contains antibiotics. Enzymes in semen primarily help with liquefaction of semen after ejaculation, not sperm motility. Choices A, B, and D are incorrect because semen does dilute sperm, neutralizes the acidic vaginal environment, and contains antibiotic chemicals, respectively.

Correct Answer: B

Rationale: Certainly. The correct answer is B: Testosterone. Interstitial cells of the testis, also known as Leydig cells, synthesize and secrete testosterone. Testosterone is the primary male sex hormone responsible for the development of male reproductive tissues and characteristics. Estrogen (A) is primarily produced in the ovaries in females. Human chorionic gonadotropin (hCG) (C) is produced by the placenta during pregnancy. Luteinizing hormone (LH) (D) is secreted by the anterior pituitary gland and stimulates the interstitial cells to produce testosterone.

Correct Answer: B

Rationale: The correct answer is B: Day 14. Ovulation typically occurs around day 14 of a female's menstrual cycle. This is because ovulation is triggered by a surge in luteinizing hormone (LH) which usually happens midway through the cycle. Ovulation marks the release of an egg from the ovary, making conception possible. Days 7, 21, and 24 are not typically associated with ovulation as they are either too early or too late in the menstrual cycle for the surge in LH to occur. It is important to note that the timing of ovulation can vary among individuals and cycles, but day 14 is considered the average for a 28-day menstrual cycle.

Correct Answer: D

Rationale: The correct answer is D: orchiditis. Orchiditis refers to inflammation of the testicle, which is a type of tissue found in the male reproductive system. This condition specifically affects the testicular tissue, leading to pain, swelling, and possible complications. Skeletal muscle (choice A) is not related to the testicle, phimosis (choice B) is a condition of the foreskin, and epithelial tissue (choice C) primarily covers the surface of organs, not the testicle itself. Therefore, orchiditis is the most relevant choice for a condition affecting testicular tissue.