1. Which hormone, produced by the thyroid gland, regulates calcium levels in the blood by enhancing calcium absorption in the intestines and reducing calcium loss in the kidneys?

A. Calcitonin
B. Parathyroid hormone (PTH)
C. Thyroxine
D. Insulin

Correct answer: a

Rationale: The correct answer is A: Calcitonin. Calcitonin is a hormone produced by the thyroid gland that plays a crucial role in regulating calcium levels in the blood. It works by enhancing calcium absorption in the intestines and reducing calcium loss in the kidneys. This helps to maintain the proper balance of calcium in the body. Parathyroid hormone (PTH) works in the opposite way, increasing calcium levels in the blood when they are low. Thyroxine is a hormone produced by the thyroid gland that regulates metabolism and growth, not calcium levels. Insulin is a hormone produced by the pancreas that regulates blood sugar levels, not calcium levels. Therefore, the correct hormone in this case is Calcitonin.

2. What is a contraceptive method that uses hormones to prevent ovulation?

A. Spermicide
B. Barrier method (condom, diaphragm)
C. Combined oral contraceptive pill
D. Intrauterine device (IUD)

Correct answer: C

Rationale: The correct answer is C: Combined oral contraceptive pill. This method uses hormones, such as estrogen and progestin, to prevent ovulation, thicken cervical mucus to block sperm, and thin the uterine lining to prevent implantation of a fertilized egg. Spermicide (A) is a chemical that kills sperm but does not prevent ovulation. Barrier methods (B) like condoms and diaphragms physically block sperm from reaching the egg. Intrauterine devices (IUDs) (D) are inserted into the uterus and work by either releasing hormones or creating a barrier to prevent fertilization, but they do not specifically target ovulation.

3. Which of the following is NOT a risk factor for developing atherosclerosis?

A. High blood pressure
B. High levels of LDL cholesterol
C. Regular physical activity
D. Smoking

Correct answer: C

Rationale: Regular physical activity is NOT a risk factor for developing atherosclerosis. In fact, engaging in regular physical activity can help reduce the risk of developing atherosclerosis by improving cardiovascular health, lowering blood pressure, and reducing LDL cholesterol levels. High blood pressure, high levels of LDL cholesterol, and smoking are all known risk factors for atherosclerosis. High blood pressure can damage blood vessels, making them more susceptible to plaque buildup. High levels of LDL cholesterol can lead to the accumulation of plaque in the arteries, narrowing the passageways and increasing the risk of atherosclerosis. Smoking is harmful to blood vessels, promoting inflammation and the formation of plaque. Therefore, regular physical activity is actually a protective factor against atherosclerosis rather than a risk factor.

4. The sentence "The audience was captivated by the speaker's compelling story" implies that the audience:

A. Was bored and disinterested.
B. Found the story confusing.
C. Was completely absorbed and engaged.
D. Disagreed with the speaker's message.

Correct answer: C

Rationale: "Captivated" suggests the audience was completely held by the speaker's story.

5. The stratum corneum, the outermost layer of the epidermis, is primarily composed of:

A. Keratinized dead cells
B. Melanocytes
C. Langerhans cells
D. Merkel cells

Correct answer: A

Rationale: The correct answer is A: 'Keratinized dead cells.' The stratum corneum is the outermost layer of the epidermis and is mainly composed of keratinized dead cells. These cells are flattened, fully keratinized, and provide a protective barrier for the skin against environmental factors such as pathogens, UV radiation, and water loss. Melanocytes (Option B), Langerhans cells (Option C), and Merkel cells (Option D) are all important components of the epidermis but are not the primary constituents of the stratum corneum. Melanocytes produce melanin, Langerhans cells are involved in the immune response, and Merkel cells are associated with the sense of touch.

6. Which of the following is NOT a function of the skeletal system?

A. Support and structure
B. Production of red blood cells
C. Storage of minerals like calcium
D. Insulation of the body

Correct answer: A

Rationale: The correct answer is A. The skeletal system provides support and structure to the body, allowing for movement and protecting internal organs. The production of red blood cells occurs in the bone marrow, which is a function of the skeletal system. Additionally, the skeletal system stores minerals like calcium, which play a crucial role in bone health and overall bodily functions. Insulation of the body is not a primary function of the skeletal system but is rather a function of adipose tissue and the integumentary system. Therefore, option A is the correct answer as it does not align with the functions of the skeletal system.