Nursing Elites

1. After exposure to a pathogen, the immune system develops memory. What type of immune cell is responsible for this immunological memory?

• A. B cells
• B. T cells (specifically memory T cells)
• C. Phagocytes
• D. Natural killer cells

Correct answer: A

Rationale: B cells are responsible for immunological memory. Memory B cells, a type of B cells, retain a 'memory' of specific pathogens, enabling them to rapidly produce antibodies upon re-exposure. This rapid antibody production facilitates a quicker and more effective immune response. Although memory T cells also contribute to immunological memory by mounting a swift and robust immune response upon re-exposure to the pathogen, it is primarily memory B cells that play a crucial role in producing antibodies. Phagocytes are important immune cells involved in engulfing and digesting pathogens, while natural killer cells are primarily responsible for recognizing and eliminating abnormal cells, such as virus-infected cells or tumor cells. However, when it comes to immunological memory and antibody production, B cells are key players.

2. What happens when a protein unfolds?

• A. Activation
• B. Denaturation
• C. Renaturation
• D. Folding

Correct answer: B

Rationale: - Activation (Option A) refers to the process of initiating or increasing the activity of a molecule, such as an enzyme. Protein unfolding does not involve activation. - Denaturation (Option B) is the correct answer. Denaturation refers to the process by which a protein loses its three-dimensional structure, leading to the disruption of its function. This can be caused by factors such as heat, pH changes, or chemicals. - Renaturation (Option C) is the process by which a denatured protein regains its native structure and function. Protein unfolding is the opposite of renaturation. - Folding (Option D) is the process by which a protein assumes its functional three-dimensional structure. Unfolding is the reverse process of folding, not folding itself.

3. Which structure do cells rely on for movement?

• A. Flagellum
• B. Microtubule
• C. Pili
• D. Vesicle

Correct answer: A

Rationale: The correct answer is A: Flagellum. Cells rely on flagella for movement, which are whip-like structures that propel the cell forward through their whipping motion. Flagella provide motility to single-celled organisms and certain cells in multicellular organisms. Microtubules, on the other hand, provide structural support to the cell and play a role in intracellular transport. Pili are short, hair-like structures used for attachment to surfaces or other cells, not for movement. Vesicles are membrane-bound sacs involved in intracellular transport, aiding in the movement of substances within the cell, but not in the movement of the cell itself.

4. Which type of joint allows for the widest range of motion, similar to the shoulder joint?

• A. Hinge joint
• B. Ball-and-socket joint
• C. Gliding joint
• D. Fixed joint

Correct answer: B

Rationale: The correct answer is B: Ball-and-socket joint. Ball-and-socket joints, like the shoulder joint, allow for the widest range of motion in multiple directions. This type of joint consists of a rounded bone (the 'ball') fitting into a cup-like socket, enabling movements such as flexion, extension, abduction, adduction, and rotation. Choice A, Hinge joint, allows movement in one plane, like a door hinge, and does not offer the same range of motion as a ball-and-socket joint. Choice C, Gliding joint, permits limited motion in various directions but not as wide as a ball-and-socket joint. Choice D, Fixed joint, does not allow any motion as it is immovable, unlike the shoulder joint which is highly mobile.

5. What is the building block of RNA?

• A. Amino acid
• B. Nucleotide
• C. Protein
• D. Fatty acid

Correct answer: B

Rationale: Nucleotide: Nucleotides are the building blocks of RNA. A nucleotide consists of a nitrogenous base (adenine, guanine, cytosine, or uracil in RNA), a sugar (ribose in RNA), and a phosphate group. A) Amino acid: Amino acids are the building blocks of proteins, not RNA. C) Protein: Proteins are made up of amino acids, not nucleotides. D) Fatty acid: Fatty acids are components of lipids, not RNA.

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