Nursing Elites

1. Which type of transport allows for the movement of large molecules, such as proteins and polysaccharides, across the cell membrane?

• A. Endocytosis
• B. Exocytosis
• C. Active transport
• D. Facilitated diffusion

Correct answer: A

Rationale: Rationale: A) Endocytosis is the process by which cells engulf large molecules or particles by wrapping the cell membrane around them to form a vesicle that is brought into the cell. This mechanism allows for the movement of large molecules, such as proteins and polysaccharides, across the cell membrane. B) Exocytosis is the opposite process of endocytosis, where cells release large molecules or particles by fusing vesicles with the cell membrane to expel their contents out of the cell. C) Active transport is a process that requires energy to move molecules across the cell membrane against their concentration gradient. While active transport can move large molecules, it is not specifically designed for the transport of proteins and polysaccharides. D) Facilitated diffusion is a type of passive transport that involves the movement of molecules across the cell membrane with the help of transport proteins. While facilitated diffusion can assist in the movement of

2. Which type of muscle tissue has a unique branching network and is found in the heart?

• A. Skeletal muscle
• B. Cardiac muscle
• C. Smooth muscle
• D. Multifidus muscle

Correct answer: B

Rationale: The correct answer is B - Cardiac muscle. Cardiac muscle is the type of muscle tissue that has a unique branching network and is specifically found in the heart. Unlike skeletal muscle, which is attached to bones and allows for voluntary movement, cardiac muscle is involuntary and contracts to pump blood throughout the body. Smooth muscle is found in organs like the intestines and blood vessels, while the multifidus muscle is a specific muscle in the back. Therefore, cardiac muscle is the appropriate choice in this scenario.

3. 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.

4. Half-life refers to the characteristic time it takes for:

• A. Radioactive intensity to completely disappear
• B. The number of neutrons in a nucleus to double
• C. The number of protons in a nucleus to change
• D. An isotope to decay by half of its initial quantity

Correct answer: D

Rationale: The correct answer is D: An isotope to decay by half of its initial quantity. The half-life of a substance is the time it takes for half of the initial quantity of radioactive atoms to decay. This is a characteristic property of each radioactive isotope and is used to determine the rate of decay of a substance. Option A is incorrect because radioactive intensity does not completely disappear in half-life, it only decreases by half. Options B and C are unrelated to the concept of half-life and do not accurately describe its definition.

5. The muscular sac that stores urine until it is released from the body is called the:

• A. Urethra
• B. Bladder
• C. Ureter
• D. Nephron

Correct answer: B

Rationale: The correct answer is B: Bladder. The bladder is a muscular sac that stores urine until it is ready to be released from the body through the urethra. The urethra is the tube that carries urine from the bladder out of the body. Ureters are tubes that carry urine from the kidneys to the bladder. Nephrons are the functional units of the kidneys responsible for filtering the blood and producing urine. Therefore, the bladder is the specific organ responsible for storing urine until it is expelled from the body, making it the correct answer.

6. What happens when a protein unfolds?

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

Correct answer: B

Rationale: 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.

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