Correct Answer: A

Rationale: The correct answer is A: Transitional epithelium. The urinary bladder is lined with transitional epithelium, a specialized type of epithelial tissue that can stretch and recoil to accommodate changes in volume as the bladder fills and empties. Stratified epithelium (choice B) is not the main lining of the urinary bladder and is found in other areas like the skin. Glandular tissue (choice C) is responsible for producing secretions and is not typically found lining the urinary bladder. Endometrium (choice D) is the inner lining of the uterus and is not present in the urinary bladder.

Correct Answer: C

Rationale: A morula is a stage in embryonic development where a solid ball of 12-16 cells is formed after several rounds of mitotic division following fertilization. The zygote is the initial cell formed by the fusion of sperm and egg. Blastomere refers to individual cells in a developing embryo. A blastocyst is a later stage where a fluid-filled cavity forms within the embryo. Therefore, the correct answer is 'Morula.'

Correct Answer: C

Rationale: The correct answer is C: Pudendal arteries. The pudendal arteries are responsible for supplying blood to the external genitalia. These arteries specifically provide blood flow to the perineum, including the external genitalia. Choice A, Femoral arteries, are not primarily responsible for supplying blood to the external genitalia. Choice B, Inguinal arteries, do not supply blood directly to the external genitalia. Choice D, Internal iliac arteries, are not the main suppliers of blood to the external genitalia.

Correct Answer: B

Rationale: Herpes simplex type 2 (HSV-2) typically causes genital herpes, not cold sores on the lips. Cold sores on the lips are commonly caused by herpes simplex type 1 (HSV-1). Therefore, the statement that HSV-2 causes cold sores of the lips is incorrect. Choice B, 'False,' is the correct answer. Choice A is incorrect because HSV-2 does not cause cold sores on the lips. Choice C, 'Depends on the person,' is incorrect as the cause of cold sores is predominantly linked to HSV-1. Choice D, 'Not enough information,' is also incorrect as this information is well-established in medical knowledge.

Correct Answer: B

Rationale: Threatening abortion is characterized by a firm contracted uterus with an open os. This presentation indicates a risk of miscarriage. Choice A ('Os open') is not specific enough and does not fully describe the condition. Choices C ('Heavy bleeding') and D ('Severe cramping') can also be present in threatening abortion, but the primary characteristic is a firm contracted uterus with an open os.