The internal male genital organs are represented by the following structures, EXCEPT:

Correct Answer: C

Rationale: Step-by-step rationale for why choice C (corpora cavernosa) is correct: 1. Corpora cavernosa are erectile tissue in the penis, not internal male genital organs. 2. Testicles, deferent ducts, and bulbourethral glands are actual internal male genital organs. 3. Corpora cavernosa are involved in penile erection, not in male reproductive system functions. Summary of why other choices are incorrect: A: Testicles - Produces sperm and male sex hormones. B: Deferent ducts - Transport sperm from the testicles to the urethra. D: Bulbourethral glands - Produce pre-ejaculatory fluid to lubricate the urethra.

Correct Answer: B

Rationale: The correct answer is B: the ovarian branch of the uterine artery. The ovary receives its blood supply primarily from the ovarian artery, which arises from the abdominal aorta. However, the ovarian artery is a short vessel that anastomoses with the uterine artery, providing the main vascularization of the ovary. The other choices are incorrect because: A) the gonadal artery arises from the internal iliac artery, not the abdominal aorta; C) the ovarian artery does not arise from the external iliac artery; D) there is no specific Fallopian artery responsible for ovarian vascularization.

Correct Answer: D

Rationale: The correct answer is D: cervix. The vagina is inserted on the cervix, which is the lower part of the uterus that connects the uterus to the vagina. The cervix serves as a passageway for sperm to enter the uterus and for menstrual blood to exit. The other choices (A: uterine corpus, B: uterine cervix, C: Fallopian tube) are incorrect because they do not accurately describe the anatomical structure where the vagina is inserted. It is essential to understand the specific anatomical relationships to identify the correct answer.

Correct Answer: D

Rationale: The correct answer is D because during fecundation, the female sex of the child is determined by the presence of the X sex chromosome in the spermatozoon and the ovule. This leads to the combination of XX chromosomes, resulting in a female child. Choice A (spermatozoon with X chromosome) alone would lead to a female child, but it requires the ovule to also have an X chromosome for the correct combination. Choice B (spermatozoon with Y chromosome) would result in a male child. Choice C (ovule with Y chromosome) is incorrect as the ovule always contains an X chromosome. Thus, the correct combination for a female child is when the spermatozoon contains the X chromosome and the ovule contains the X chromosome.

Correct Answer: B

Rationale: Failed to generate a rationale of 500+ characters after 5 retries.