Nursing Elites

1. Passive transport does not require energy input from the cell. Which of the following is an example of passive transport?

• A. Active transport of ions across a membrane
• B. Diffusion of small molecules across a concentration gradient
• C. Movement of large molecules using vesicles
• D. Endocytosis of particles into the cell

Correct answer: B

Rationale: Passive transport refers to the movement of molecules across a cell membrane without the input of energy. Diffusion of small molecules across a concentration gradient is a classic example of passive transport, as it occurs spontaneously from an area of high concentration to an area of low concentration. Active transport (option A) requires energy input in the form of ATP to move substances against their concentration gradient. Movement of large molecules using vesicles (option C) involves processes like endocytosis and exocytosis that require energy in the form of ATP. Endocytosis of particles into the cell (option D) is an active process that requires energy expenditure by the cell to engulf and internalize extracellular substances.

2. Which statement accurately describes cytokinesis in animal cells?

• A. Which statement accurately describes cytokinesis in animal cells?
• B. A cell plate forms in the center of the dividing cell, eventually separating the cytoplasm into two daughter cells.
• C. A cell plate forms in the center of the dividing cell, eventually separating the cytoplasm into two daughter cells.
• D. The nucleus elongates and pulls apart, physically dividing the cytoplasm into two.

Correct answer: B

Rationale: A) This statement is a duplicate of option C and does not accurately describe cytokinesis in animal cells. B) In animal cells, during cytokinesis, a cleavage furrow forms in the center of the dividing cell. This furrow deepens and eventually pinches the cytoplasm into two daughter cells. This process is distinct from plant cells, where a cell plate forms. C) This statement is a duplicate of option A and does not accurately describe cytokinesis in animal cells. D) This statement describes the process of nuclear division (mitosis) rather than cytokinesis, which is the division of the cytoplasm.

3. How do killer T cells recognize infected cells?

• A. The B cells flag the infected cells with amino acids.
• B. Tiny bits of the virus's RNA are left around the cell.
• C. Macrophages show up to help consume the infected cell.
• D. The T cells have receptors that recognize the proteins the virus leaves on the surface of the cell.

Correct answer: D

Rationale: Killer T cells recognize infected cells by detecting viral proteins displayed on the surface of these cells. The T cells possess receptors specifically designed to identify these viral proteins, allowing them to target and eliminate the infected cells. Choice A is incorrect because B cells are not directly involved in the recognition process of infected cells by killer T cells. Choice B is incorrect because tiny bits of the virus's RNA being left around the cell is not how killer T cells primarily recognize infected cells. Choice C is incorrect because while macrophages play a role in immune responses, they do not directly assist in the recognition of infected cells by killer T cells.

4. What is the primary function of platelets in the blood?

• A. To carry oxygen
• B. To clot blood
• C. To fight infection
• D. To transport nutrients

Correct answer: B

Rationale: The correct answer is B: 'To clot blood.' Platelets play a crucial role in the clotting process, forming a plug at the site of blood vessel injury to prevent excessive bleeding. While red blood cells carry oxygen, white blood cells fight infection, and nutrients are transported by plasma, platelets are specifically responsible for blood clotting. Choice A is incorrect because red blood cells are responsible for carrying oxygen. Choice C is incorrect because white blood cells are primarily involved in fighting infection. Choice D is incorrect as the transport of nutrients is mainly carried out by plasma, not platelets.

5. Which part of the spinal cord is responsible for transmitting sensory information from the body to the brain?

• A. Dorsal root
• B. Ventral root
• C. Gray matter
• D. White matter

Correct answer: A

Rationale: The correct answer is the dorsal root. The dorsal root of the spinal cord contains sensory nerve fibers that transmit sensory information from the body to the brain. This information includes touch, pain, temperature, and proprioception. The ventral root, on the other hand, contains motor nerve fibers responsible for carrying signals from the brain to the muscles and glands, controlling movement and glandular functions. Gray matter, consisting mainly of cell bodies, is involved in processing and integrating sensory and motor information within the spinal cord. White matter is primarily composed of myelinated axons that facilitate communication between different regions of the nervous system, allowing signals to travel efficiently within the spinal cord and between the brain and other parts of the body. Therefore, the dorsal root is specifically associated with transmitting sensory information, making it the correct answer in this context.

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