1. The protective fluid surrounding the brain and spinal cord is called:

A. Blood
B. Cerebrospinal fluid
C. Plasma
D. Myelin

Correct answer: B

Rationale: The correct answer is B: Cerebrospinal fluid. Cerebrospinal fluid is a clear, colorless liquid that surrounds the brain and spinal cord, providing cushioning and protection against physical impact. It also helps to maintain a stable environment for the central nervous system by regulating pressure and removing waste products. Blood (option A) is not the fluid that directly surrounds the brain and spinal cord. Plasma (option C) is the liquid component of blood and is not specific to the central nervous system. Myelin (option D) is a fatty substance that forms a protective sheath around nerve fibers but is not the fluid surrounding the brain and spinal cord.

2. Osteoporosis is a condition leading to weakened bones and increased risk of fractures. Which hormone plays a key role in bone health and is often affected in osteoporosis?

A. Estrogen
B. Testosterone
C. Thyroid hormone
D. Insulin

Correct answer: A

Rationale: Estrogen plays a crucial role in bone health by promoting the activity of bone-forming cells and inhibiting bone breakdown. In women, estrogen levels decrease significantly during menopause, leading to a higher risk of osteoporosis. This hormone helps maintain bone density and strength, making it essential for preventing bone loss and fractures. Testosterone, while important for overall health, does not have as significant of an impact on bone health as estrogen does. Thyroid hormone and insulin also have roles in the body, but they are not as directly linked to bone health as estrogen. Therefore, the correct answer is A: Estrogen.

3. What is the neurotransmitter involved in muscle movement?

A. Dopamine
B. Acetylcholine
C. Serotonin
D. GABA

Correct answer: B

Rationale: The correct answer is B: Acetylcholine. Acetylcholine is the neurotransmitter involved in muscle movement. It is released by motor neurons at the neuromuscular junction to stimulate muscle contraction. Dopamine is involved in reward and pleasure pathways in the brain, serotonin plays a role in mood regulation, and GABA is an inhibitory neurotransmitter that helps to reduce neural activity. Understanding the specific roles of neurotransmitters is crucial in grasping their functions in the nervous system.

4. What is the role of DNA in heredity?

A. Provides energy for the cell
B. Determines the structure and function of proteins
C. Stores and transmits genetic information
D. Controls cell division

Correct answer: C

Rationale: Rationale: DNA (deoxyribonucleic acid) is a molecule that carries the genetic instructions used in the growth, development, functioning, and reproduction of all living organisms. It stores genetic information in the form of a code made up of four chemical bases: adenine (A), thymine (T), cytosine (C), and guanine (G). This genetic information is passed down from parents to offspring and is responsible for determining an organism's traits and characteristics. DNA does not provide energy for the cell (option A), determine the structure and function of proteins (option B), or control cell division (option D).

5. What type of energy is possessed by an object due to its position or configuration?

A. Kinetic energy
B. Thermal energy
C. Potential energy
D. Electrical energy

Correct answer: c

Rationale: Potential energy is the energy possessed by an object due to its position or state.

6. Which structure helps regulate body temperature by constricting or dilating in response to temperature changes?

A. Sebaceous glands
B. Hair follicles
C. Sweat glands
D. Langerhans cells

Correct answer: C

Rationale: The correct answer is C: Sweat glands. Sweat glands play a crucial role in regulating body temperature by producing sweat that evaporates from the skin surface, cooling the body when it's hot. Sweat glands can constrict to reduce sweating in cooler temperatures and dilate to increase sweating when the body needs to cool down. Sebaceous glands are responsible for producing oil to lubricate the skin and hair follicles help in hair growth. Langerhans cells are immune cells in the skin. Therefore, sweat glands are the structure specifically involved in regulating body temperature through constriction and dilation in response to temperature changes.