An egg that has been fertilized by a sperm is called a _______________.

Correct Answer: B

Rationale: The correct answer is B: zygote. After fertilization, when the sperm and egg unite, they form a zygote. This is the initial stage of a new organism's development. Implantation (A) occurs when the embryo attaches to the uterus. Embryo (C) is the term for the developing organism after the zygote stage. Breast (D) is not related to the fertilization process. In this context, zygote is the most appropriate term as it specifically refers to the newly formed cell after fertilization.

Correct Answer: A

Rationale: The correct answer is A because the arterial vascularization of the testicle is indeed provided by the gonadal artery, which is a branch off the abdominal aorta. This is anatomically accurate as the gonadal artery supplies blood to the testicles. Choice B is incorrect because the venous drainage of the testicle is to the testicular vein, which drains into the inferior vena cava, not the internal iliac vein as stated in option B. Choice C is incorrect because the testicular artery, not the internal iliac artery, is responsible for the arterial supply to the testicle. Choice D is incorrect because the venous drainage of the testicle is not tributary to the inferior vena cava; instead, it drains into the left renal vein.

Correct Answer: A

Rationale: Correct Answer: A Rationale: Spermatogenesis is a complex process involving several stages such as mitosis, meiosis, and maturation. It starts with the division of spermatogonia through mitosis, followed by meiosis I and II to form haploid spermatids. These spermatids then undergo maturation to become spermatozoa. Therefore, spermatogenesis occurs in several stages, making choice A the correct answer. Summary of Incorrect Choices: B: While spermatogenesis does involve meiosis, it includes both meiosis I and II, not just meiosis I. C: Spermatogenesis includes both meiosis I and II, not just meiosis II. D: Spermatogenesis is primarily regulated by hormones such as testosterone and LH, not FSH.

Correct Answer: D

Rationale: The correct answer is D because the ovary is not located in the right flank; it is located in the lower abdomen. A: The ovary is a pair organ, as there are two ovaries in the female reproductive system. B: The ovary is a gland with mixed roles, producing hormones and releasing eggs. C: The ovary is oval-shaped, which is anatomically correct. Therefore, choice D is incorrect as the ovary is not located in the right flank.

Correct Answer: D

Rationale: The correct answer is D: internal iliac vein. The veins of the ovary drain into the ovarian veins, which then connect to the pampiniform plexus, ultimately draining into the internal iliac vein. This pathway allows for the blood from the ovary to be carried back to the heart. The other choices (A, B, C) are incorrect as the ovarian veins do not typically open into the inferior vena cava, uterine vein, or renal vein.