Nursing Elites

1. 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: 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.

2. What macromolecules are formed from amino acids, and what are their roles?

• A. Lipids; store energy
• B. Carbohydrates; provide energy
• C. Proteins; perform various functions like catalysis, transport, and structural support
• D. Nucleic acids; store genetic information

Correct answer: C

Rationale: The correct answer is C. Proteins are macromolecules formed from amino acids and have diverse roles, such as serving as enzymes, transport molecules, and providing structural support. They are essential for catalysis, cellular communication, immune response, and many other functions in living organisms. Choices A, B, and D are incorrect. Lipids are not formed from amino acids but from fatty acids and glycerol, mainly serving as energy storage molecules. Carbohydrates are composed of sugars and provide energy to the body. Nucleic acids, like DNA and RNA, are made up of nucleotides and store genetic information in cells.

3. What is the tough, fibrous tissue that connects bones at joints called?

• A. Cartilage
• B. Ligaments
• C. Tendons
• D. Fascia

Correct answer: B

Rationale: Ligaments are the tough, fibrous tissue that connects bones at joints, providing stability and support to prevent excessive movement and potential injury. Cartilage is a smooth, rubbery connective tissue that covers bone ends at joints. Tendons connect muscles to bones, enabling movement. Fascia surrounds muscles, blood vessels, and nerves, providing support and structure to these tissues. In this context, ligaments are specifically the connective tissues that bind bones together at joints, not cartilage, tendons, or fascia.

4. Which part of the neuron receives signals from other neurons?

• A. Axon
• B. Dendrite
• C. Synapse
• D. Myelin sheath

Correct answer: B

Rationale: The correct answer is B, Dendrite. Dendrites are the part of the neuron that receive signals from other neurons and transmit them to the cell body. Axons transmit signals away from the cell body, synapse is the junction between neurons where neurotransmitters are released, and myelin sheath is a fatty layer that insulates and speeds up signal conduction along the axon. Therefore, choices A, C, and D are incorrect in the context of receiving signals from other neurons.

5. Which of the following is responsible for regulating body temperature?

• A. Hypothalamus
• B. Cerebellum
• C. Pituitary gland
• D. Thyroid gland

Correct answer: A

Rationale: The correct answer is the Hypothalamus. The hypothalamus plays a crucial role in regulating body temperature, hunger, thirst, and maintaining overall homeostasis in the body. It receives input from temperature receptors in the skin and internal organs and helps initiate responses to maintain a stable internal body temperature. Acting as the body's thermostat, the hypothalamus adjusts responses to ensure the body's temperature remains within a narrow range, despite external conditions. The Cerebellum (Choice B) is primarily involved in coordinating movement and balance, not regulating body temperature. The Pituitary gland (Choice C) is responsible for producing and secreting hormones that regulate various bodily functions but not directly involved in body temperature regulation. The Thyroid gland (Choice D) plays a role in metabolism and hormone regulation but is not the primary regulator of body temperature.

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