Nursing Elites

1. What is the difference between DNA and RNA?

• A. Both are double-stranded.
• B. DNA contains deoxyribose sugar, while RNA contains ribose sugar.
• C. RNA contains the nitrogenous base uracil, while DNA contains thymine.
• D. Both are identical molecules.

Correct answer: B

Rationale: Rationale: A) Incorrect. DNA is double-stranded, but RNA is typically single-stranded. B) Correct. DNA contains deoxyribose sugar, which lacks an oxygen atom on the 2' carbon of the sugar ring, while RNA contains ribose sugar, which has an additional hydroxyl group on the 2' carbon. C) Incorrect. RNA contains the nitrogenous base uracil, while DNA contains thymine. D) Incorrect. DNA and RNA have distinct structures and functions, so they are not identical molecules.

2. Define work in physics.

• A. Force applied to an object at rest
• B. Force exerted by an object in motion
• C. Transfer of energy through motion along a direction
• D. Measure of an object's potential energy

Correct answer: c

Rationale: Work in physics is the transfer of energy when a force is applied and the object moves in the direction of the force.

3. The external body covering, providing protection and contributing to temperature regulation, is composed of:

• A. Muscle tissue
• B. Epithelial tissue (skin)
• C. Bone marrow
• D. Cartilage

Correct answer: B

Rationale: The correct answer is B: Epithelial tissue (skin). The skin is the external body covering that provides protection against physical, chemical, and biological factors. It also plays a crucial role in regulating body temperature by controlling heat exchange with the environment through processes like sweating and blood vessel constriction or dilation. Muscle tissue (option A) is responsible for movement, bone marrow (option C) produces blood cells, and cartilage (option D) is a type of connective tissue found in joints. Therefore, epithelial tissue (skin) is the most suitable option as it directly addresses the functions of the external body covering.

4. Antibodies, crucial for immune defense, are produced by:

• A. Neutrophils
• B. Lymphocytes
• C. Monocytes
• D. Basophils

Correct answer: B

Rationale: The correct answer is B: Lymphocytes. Antibodies, also known as immunoglobulins, are produced by B lymphocytes (B cells) as a key component of the adaptive immune response. These specialized cells play a crucial role in recognizing and neutralizing pathogens, thereby providing immunity against infections. Neutrophils (A) are a type of white blood cell involved in innate immunity and phagocytosis. Monocytes (C) are another type of white blood cell that can differentiate into macrophages, which are important in phagocytosis and antigen presentation. Basophils (D) are involved in allergic responses and inflammation through the release of histamine. Lymphocytes, particularly B cells, are primarily responsible for antibody production in response to pathogens and foreign substances.

5. A car is moving in a circle at constant speed. Which of the following is NOT true about its motion?

• A. It has a constant centripetal acceleration
• B. It has a constant tangential velocity
• C. It experiences a force directed towards the center of the circle
• D. It covers the same distance in equal time intervals along its circular path

Correct answer: B

Rationale: In circular motion at a constant speed, the car has a constant centripetal acceleration (choice A), experiences a force directed towards the center of the circle (choice C), and covers the same distance in equal time intervals along its circular path (choice D). However, the tangential velocity of an object in circular motion at a constant speed changes continuously as it moves around the circle, so it is not constant (choice B).

6. Which property of a substance describes how much matter is packed into a given space?

• A. Mass
• B. Volume
• C. Weight
• D. Density

Correct answer: D

Rationale: Density is the property of a substance that describes how much matter is packed into a given space. It is calculated by dividing the mass of the substance by its volume. Mass refers to the amount of matter in an object, volume is the amount of space an object occupies, and weight is the force of gravity acting on an object's mass. Density specifically relates to how tightly packed the particles of a substance are.

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