Nursing Elites

1. 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.

2. What is the endoplasmic reticulum?

• A. A network of tubules that transport proteins and lipids throughout the cell
• B. A sac-like structure that stores water and nutrients
• C. The site of protein synthesis
• D. The site of cellular respiration

Correct answer: A

Rationale: Rationale: A) The endoplasmic reticulum (ER) is a network of tubules that are involved in the transport of proteins and lipids throughout the cell. It plays a crucial role in protein synthesis, folding, and transport within the cell. The ER can be further divided into rough ER, which has ribosomes attached to its surface and is involved in protein synthesis, and smooth ER, which is involved in lipid metabolism and detoxification. Therefore, option A is the most accurate description of the endoplasmic reticulum compared to the other options provided. B) A sac-like structure that stores water and nutrients does not accurately describe the endoplasmic reticulum. While some organelles like vacuoles or vesicles may store water and nutrients, the ER's primary function is not storage. C) The site of protein synthesis is partially

3. What is the common name for the organic compound CH₃OH?

• A. Methane
• B. Ethanol
• C. Methanol
• D. Butanol

Correct answer: C

Rationale: CH₃OH is commonly known as methanol. The other choices represent different organic compounds.

4. Which type of cell division is responsible for sexual reproduction?

• A. Mitosis
• B. Meiosis
• C. Amitosis
• D. Cytokinesis

Correct answer: B

Rationale: Rationale: Meiosis is the type of cell division responsible for sexual reproduction. During meiosis, a single cell undergoes two rounds of division to produce four daughter cells, each with half the number of chromosomes as the parent cell. This reduction in chromosome number is essential for sexual reproduction, as it ensures that when two gametes (sperm and egg) combine during fertilization, the resulting zygote will have the correct number of chromosomes. Mitosis, on the other hand, is a type of cell division that produces two daughter cells with the same number of chromosomes as the parent cell and is involved in growth, repair, and asexual reproduction. Amitosis is a rare form of cell division that does not involve the typical processes of mitosis or meiosis. Cytokinesis is the process of dividing the cytoplasm of a cell after mitosis or meiosis.

5. Which of the following terms refers to a muscle that lengthens while another muscle contracts to produce movement?

• A. Synergist
• B. Agonist
• C. Antagonist
• D. Flexor

Correct answer: C

Rationale: The correct answer is C: Antagonist. In muscle physiology, an antagonist refers to a muscle that lengthens while another muscle contracts to produce movement. This relationship allows for smooth and coordinated movement by controlling the action of the agonist muscle. For example, when you bend your arm, the biceps muscle (agonist) contracts to flex the arm while the triceps muscle (antagonist) lengthens to allow for this movement. Synergists assist the agonist muscle in performing a movement, while flexors are a type of muscle that decreases the angle between bones at a joint. Therefore, the antagonist best fits the description of a muscle that lengthens while another muscle contracts.

6. Which type of muscle is characterized by voluntary control and is responsible for body movement?

• A. Cardiac muscle
• B. Smooth muscle
• C. Skeletal muscle
• D. Connective tissue

Correct answer: c

Rationale: The correct answer is C: Skeletal muscle. Skeletal muscles are characterized by voluntary control, meaning they are under conscious control, allowing us to move our body parts as desired. These muscles are attached to bones and are responsible for movements such as walking, running, and lifting objects. Cardiac muscle (A) is found in the heart and is involuntary, while smooth muscle (B) is found in internal organs and is also involuntary. Connective tissue (D) provides support and structure to the body but is not responsible for body movements.

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