1. The fluid-filled, jelly-like substance within the cell that suspends the organelles is called the:

A. Nucleus
B. Cytoplasm
C. Plasma membrane
D. Golgi apparatus

Correct answer: B

Rationale: The correct answer is B: Cytoplasm. Cytoplasm is the fluid-filled, jelly-like substance within the cell that suspends the organelles. It is where many cellular processes take place, such as metabolism and protein synthesis. The nucleus (option A) is the organelle that contains the cell's genetic material, the plasma membrane (option C) is the outer boundary of the cell that regulates what enters and exits the cell, and the Golgi apparatus (option D) is involved in processing and packaging proteins. Understanding the functions of each organelle is crucial in recognizing that the cytoplasm is the correct answer in this context.

2. Eliminate the function NOT attributed to the lymphatic system.

A. Fluid drainage from tissues
B. Immune response via white blood cell production
C. Nutrient transport throughout the body
D. Waste removal through lymph nodes

Correct answer: C

Rationale: Rationale: A) Fluid drainage from tissues: This function is attributed to the lymphatic system. Lymphatic vessels collect excess fluid from tissues and return it to the bloodstream. B) Immune response via white blood cell production: The lymphatic system plays a crucial role in the body's immune response by producing and transporting white blood cells, such as lymphocytes, which help fight infections. C) Nutrient transport throughout the body: Nutrient transport is primarily carried out by the circulatory system (blood vessels), not the lymphatic system. The circulatory system transports nutrients, oxygen, and hormones to cells and removes waste products. D) Waste removal through lymph nodes: The lymphatic system helps remove waste and toxins from the body by filtering lymph through lymph nodes, where harmful substances are trapped and destroyed by immune cells. Therefore, the function NOT attributed to the lymphatic system is C) Nutrient transport throughout the body.

3. Which hormone, produced by the thyroid gland, plays a key role in regulating calcium levels in the blood by promoting calcium release from bones and increasing calcium reabsorption in the kidneys?

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

Correct answer: b

Rationale: The correct answer is B: Parathyroid hormone (PTH). PTH is produced by the parathyroid glands, not the thyroid gland. PTH plays a crucial role in regulating calcium levels in the blood by promoting calcium release from bones and increasing calcium reabsorption in the kidneys. This hormone acts in opposition to calcitonin, which is produced by the thyroid gland and works to lower blood calcium levels by promoting calcium deposition into bones. Thyroxine (C) is a thyroid hormone that regulates metabolism, not calcium levels. Insulin (D) is a hormone produced by the pancreas that regulates blood sugar levels, not calcium levels.

4. Antigenic variation, a common strategy used by some viruses, allows them to:

A. Produce toxins
B. Evade the immune system
C. Survive outside a host
D. Replicate rapidly

Correct answer: B

Rationale: Rationale: Antigenic variation is a strategy used by some viruses to evade the host's immune response. By constantly changing their surface antigens, viruses can avoid recognition and destruction by the immune system. This allows the virus to persist in the host and continue replicating, leading to prolonged infection and potential transmission to other hosts. Antigenic variation does not directly involve the production of toxins, survival outside a host, or rapid replication, making options A, C, and D incorrect in this context.

5. What kind of lens focuses parallel light rays to a single point?

A. Concave lens
B. Convex lens
C. Cylindrical lens
D. Plano lens

Correct answer: B

Rationale: Convex lenses (converging lenses) bend incoming light rays inwards, focusing them to a point called the focal point.

6. Which division of the nervous system is responsible for involuntary functions such as heart rate, digestion, and respiratory rate?

A. Somatic nervous system
B. Autonomic nervous system
C. Peripheral nervous system
D. Central nervous system

Correct answer: b

Rationale: The correct answer is B: Autonomic nervous system. The autonomic nervous system is responsible for regulating involuntary functions in the body, such as heart rate, digestion, respiratory rate, and other automatic processes. The somatic nervous system (A) controls voluntary muscle movements, the peripheral nervous system (C) consists of nerves outside the brain and spinal cord, and the central nervous system (D) includes the brain and spinal cord. Understanding the functions and divisions of the nervous system is crucial for grasping how different bodily processes are controlled and regulated.