Which of the following describes oviparity?

Correct Answer: D

Rationale: Oviparity refers to the reproductive mode where organisms lay eggs that hatch outside the body. Choice D is correct as it describes frogs hatching from shell-covered fertilized eggs within the female's body. This is because frogs lay eggs externally after fertilization, and the eggs hatch into tadpoles outside the female's body. Choices A and B are incorrect as they describe viviparity, where offspring are fully developed at birth and young mammals obtain nourishment from the mother's placenta, respectively. Choice C is incorrect as it describes ovoviviparity, where embryos develop inside eggs within the mother's body but are born live.

Correct Answer: C

Rationale: The correct answer is C: gastrula. During the gastrula stage of embryonic development, the blastula undergoes a process called gastrulation, where the three primary germ layers - ectoderm, mesoderm, and endoderm - are formed. The ectoderm gives rise to the nervous system and skin, the mesoderm forms muscles and organs, and the endoderm develops into the lining of the digestive tract and respiratory system. Morula (A) is an earlier stage where the zygote divides into multiple cells. Blastula (B) is the stage before gastrula where a hollow ball of cells is formed. Neurula (D) is a stage specific to vertebrate embryos where the neural tube begins to form.

Correct Answer: C

Rationale: The correct answer is C: Epithelial hyperplasia. Fibrocytic disease involves nonproliferative and proliferative fibrocystic changes in the breast tissue. Epithelial hyperplasia is a common proliferative change seen in fibrocystic disease, characterized by increased number of epithelial cells in the ducts and lobules. Apocrine metaplasia, choice A, is another common change in fibrocystic disease but is not specific to morphology. Proliferation of ductules, choice B, is not a characteristic feature of fibrocystic disease. Giant cells, choice D, are not typically associated with fibrocystic changes.

Correct Answer: B

Rationale: The correct answer is B: Increased size of the uterus. In a 72-year-old woman, an increased size of the uterus can indicate potential issues such as fibroids or endometrial hyperplasia, which may require further investigation. Thinning of pubic hair (A) is a common age-related change. Decreased size of the clitoris (C) and loss of tone of the pelvic ligaments (D) can also occur with aging but are not typically concerning findings during a routine physical exam in this age group.

Correct Answer: C

Rationale: The correct answer is C: ampulla. The ampulla is a dilated portion at the end of the vas deferens where it joins with the duct of the seminal vesicle to form the ejaculatory duct. This structure serves as a storage and mixing area for sperm and seminal fluid before ejaculation. The other choices, A: ductus deferens, is another name for the vas deferens itself; B: seminal vesicle is a gland that produces seminal fluid but is not the dilated sac at the end of the vas deferens; D: ejaculatory duct is formed by the union of the vas deferens and the duct of the seminal vesicle, it is not the dilated sac itself.