Nursing Elites

1. What is the small repeating unit in the contractile apparatus of skeletal muscle?

• A. Myofibril
• B. Actin
• C. Sarcomere
• D. Myosin

Correct answer: C

Rationale: The correct answer is 'Sarcomere.' The sarcomere is the smallest repeating unit within myofibrils and is responsible for muscle contraction in skeletal muscle. It consists of overlapping actin and myosin filaments arranged in a highly organized structure that allows for the sliding of filaments during muscle contraction. 'Myofibril' (choice A) is incorrect because it is a larger structure composed of sarcomeres. 'Actin' (choice B) and 'Myosin' (choice D) are incorrect as they are individual proteins that are components of the sarcomere, not the smallest repeating unit itself.

2. Which of the following situations represents work being done on an object?

• A. Pushing against a wall without moving it
• B. Carrying a heavy object without lifting it
• C. Lifting a box to place it on a shelf
• D. Holding a book stationary in your hand

Correct answer: C

Rationale: Work is defined as the product of the force applied to an object and the distance over which the force is applied. In the situation of lifting a box to place it on a shelf, work is being done on the object. This is because lifting the box involves applying a force over a distance (the height of the shelf). The force applied to lift the box results in work being done on the object by raising it against the force of gravity. Choices A, B, and D do not involve work being done on the object as they either do not involve movement against a force (A, D) or do not cover distance against a force (B).

3. A symbiotic relationship where one organism benefits and the other is not harmed is called:

• A. Mutualism
• B. Commensalism
• C. Parasitism
• D. Predation

Correct answer: B

Rationale: B) Commensalism: In commensalism, one organism benefits while the other is neither helped nor harmed. This is the relationship described in the question. The correct answer is Commensalism because it specifically fits the scenario where one organism benefits without affecting the other. A) Mutualism: In mutualism, both organisms involved benefit from the relationship. C) Parasitism: In parasitism, one organism benefits at the expense of the other organism, which is harmed. D) Predation: In predation, one organism (predator) kills and consumes another organism (prey) for food.

4. What is a condition characterized by an overactive thyroid gland and excessive production of thyroid hormones called?

• A. Diabetes mellitus
• B. Hyperthyroidism
• C. Hypothyroidism
• D. Cushing's syndrome

Correct answer: B

Rationale: Hyperthyroidism is a condition where the thyroid gland is overactive and produces an excessive amount of thyroid hormones. This can lead to symptoms such as weight loss, rapid heartbeat, sweating, and nervousness. Diabetes mellitus is a condition characterized by high blood sugar levels due to either insufficient insulin production or the body's inability to respond to insulin. Hypothyroidism is the opposite of hyperthyroidism, where the thyroid gland is underactive and produces insufficient thyroid hormones. Cushing's syndrome is a disorder that occurs when the body has a high level of the hormone cortisol for a long time.

5. How many neutrons are in an atom of the following element with a mass number of 50?

• A. 38
• B. 88
• C. 50
• D. 126

Correct answer: C

Rationale: Neutrons are found in the nucleus of an atom along with protons. To determine the number of neutrons in an atom, subtract the atomic number (number of protons) from the mass number. In this case, the mass number given is 50. Since the atomic number is not specified, we can infer it from the choices provided. The mass number of an element represents the total sum of protons and neutrons in the nucleus. Therefore, the number of neutrons in this atom would also be 50, as the mass number is equivalent to the combined number of protons and neutrons, making choice C the correct answer. Choices A, B, and D are incorrect as they do not match the given mass number of 50.

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