1. Which blood vessels are responsible for carrying oxygenated blood away from the heart to the rest of the body?

A. Veins
B. Arteries
C. Capillaries
D. Venules

Correct answer: B

Rationale: The correct answer is B: Arteries. Arteries are blood vessels that carry oxygenated blood away from the heart to the rest of the body. They have thick and elastic walls to withstand the high pressure generated by the pumping action of the heart. Veins, on the other hand, carry deoxygenated blood back to the heart, while capillaries are tiny blood vessels where the exchange of oxygen and nutrients occurs. Venules are small veins that collect blood from capillaries and transport it to larger veins. Therefore, arteries are specifically designed to transport oxygenated blood away from the heart, making them the correct choice in this question.

2. Which of the following is the primary function of the ovaries in the female reproductive system?

A. Transport sperm to the uterus
B. Produce milk for feeding offspring
C. Produce eggs (ova)
D. Regulate urination

Correct answer: C

Rationale: The primary function of the ovaries in the female reproductive system is to produce eggs (ova). Ovaries are responsible for the production and release of eggs during the menstrual cycle, which can be fertilized by sperm to form a zygote. This process is essential for reproduction and the continuation of the species. Options A, B, and D are incorrect as transporting sperm to the uterus is the role of the fallopian tubes, producing milk for feeding offspring is the function of the mammary glands, and regulating urination is controlled by the bladder and associated muscles, not the ovaries.

3. Bone is a type of

A. Epithelial tissue
B. Connective tissue
C. Hard connective tissue
D. Muscle tissue

Correct answer: C

Rationale: The correct answer is C: "Hard connective tissue." Bone is classified as hard connective tissue because it is composed of cells embedded in a matrix of mineralized collagen fibers, providing support and protection to the body. Epithelial tissue (A) covers body surfaces and lines cavities, while connective tissue (B) includes bone, cartilage, and blood. Muscle tissue (D) is responsible for movement and is not the same as bone tissue.

4. Which of the following is NOT a function of the muscular system?

A. Movement
B. Maintaining posture
C. Generating heat
D. Regulating blood sugar levels

Correct answer: D

Rationale: The correct answer is D: "Regulating blood sugar levels." The muscular system primarily functions in movement, maintaining posture, and generating heat. Muscles contract and relax to allow movement and help us stay upright. They also produce heat through muscle contractions to maintain body temperature. Regulating blood sugar levels is primarily controlled by the endocrine system, specifically the pancreas and hormones like insulin and glucagon. Therefore, this function is not directly related to the muscular system.

5. What is the main reason why elements in Group 18 (Noble gases) are generally unreactive?

A. They have high atomic masses
B. They lack valence electrons
C. Their outermost electron shells are completely filled
D. They exist as single atoms, not molecules

Correct answer: C

Rationale: Noble gases have their outermost electron shells filled with 8 electrons, achieving a stable configuration with minimal urge to gain or lose electrons, making them less prone to chemical reactions.

6. Which hormone primarily triggers ovulation in the female menstrual cycle?

A. Estrogen
B. Progesterone
C. Luteinizing hormone (LH)
D. Follicle-stimulating hormone (FSH)

Correct answer: C

Rationale: The correct answer is C: Luteinizing hormone (LH). LH is the hormone responsible for triggering ovulation in the female menstrual cycle. During the menstrual cycle, LH surge occurs around day 14, which stimulates the release of a mature egg from the ovary. This surge in LH is crucial for the rupture of the mature follicle and the release of the egg, marking the onset of ovulation. Estrogen and progesterone play important roles in regulating the menstrual cycle, but LH specifically triggers ovulation by signaling the release of the egg from the ovary.