1. The primary function of the placenta during pregnancy is to:

A. Produce insulin
B. Facilitate gas exchange between mother and fetus
C. Excrete waste products from the fetus
D. All of the above

Correct answer: D

Rationale: The correct answer is D, 'All of the above.' The placenta serves multiple crucial functions during pregnancy. It facilitates gas exchange between the mother and fetus, ensuring the transfer of oxygen and nutrients while removing carbon dioxide and waste products. Additionally, the placenta produces hormones like insulin that help regulate the mother's metabolism and support the development of the fetus. Therefore, the placenta plays a vital role in maintaining a healthy environment for the growing fetus by providing essential nutrients, removing waste, and regulating hormonal balance.

2. Fingernails and toenails are made primarily of:

A. Collagen (Collagen is found in the dermis)
B. Keratin
C. Melanin (Melanin provides pigment, not structure)
D. Sebum (Sebum is an oily substance)

Correct answer: B

Rationale: The correct answer is B: Keratin. Fingernails and toenails are primarily made of a tough protein called keratin. Keratin is a fibrous structural protein that also makes up hair and the outer layer of skin. Collagen, as mentioned in option A, is found in the dermis of the skin and is responsible for providing strength and elasticity to the skin. Melanin, as in option C, is a pigment that gives color to the skin, hair, and eyes, but it does not contribute to the structure of nails. Sebum, as in option D, is an oily substance produced by the sebaceous glands in the skin to moisturize and protect the skin, but it is not a component of nails.

3. The formula for calculating ideal body weight (IBW) for men is IBW (kg) = 50 + 2.3 * (height in cm - 150). If a man is 180cm tall, what is his ideal body weight?

A. 68kg
B. 71kg
C. 74kg
D. 77kg

Correct answer: C

Rationale: Substitute the man's height (180cm) into the formula: IBW = 50 + 2.3 * (180 - 150) = 74kg.

4. A scientist observes a new species of plant with unusual leaves. They hypothesize that the leaves help capture more sunlight. Which observation would LEAST support this hypothesis?

A. The plant grows in shady environments.
B. The leaves have a large surface area.
C. The leaves contain high levels of chlorophyll.
D. The plant has shallow roots.

Correct answer: A

Rationale: If the plant thrives in shade, it suggests the leaves may have adapted for other purposes than maximizing sunlight capture.

5. Which element is a critical component of DNA and RNA, essential for storing and transmitting genetic information?

A. Oxygen
B. Carbon
C. Nitrogen
D. Hydrogen

Correct answer: B

Rationale: Carbon's ability to form diverse bonds makes it the backbone of genetic molecules, enabling efficient information storage and transmission

6. Locate the heart within the human body cavities.

A. Dorsal cavity
B. Ventral cavity
C. Thoracic cavity
D. Abdominal cavity

Correct answer: C

Rationale: Rationale: The heart is located within the thoracic cavity, specifically in the mediastinum, which is the central compartment of the thoracic cavity. The thoracic cavity is part of the ventral cavity, which also includes the abdominal cavity. The dorsal cavity refers to the posterior side of the body and does not contain the heart. The heart is situated in the thoracic cavity between the lungs and above the diaphragm, making option C the correct choice.