Nursing Elites

1. What is the structure of DNA?

• A. Single-stranded, linear
• B. Double-stranded, linear
• C. Double-stranded, helix
• D. Single-stranded, helix

Correct answer: C

Rationale: The correct answer is C: Double-stranded, helix. DNA is structured as a double helix formed by two strands of nucleotides. The nucleotides are paired with complementary bases (A-T and C-G) in the center, held together by hydrogen bonds. This double-stranded helical structure is a fundamental characteristic of DNA and essential for its function in storing genetic information. Choices A, B, and D are incorrect because DNA is not single-stranded; it consists of two strands that run antiparallel to each other and are connected via hydrogen bonds. Additionally, DNA does not have a linear structure but rather a helical one, providing stability and protection to the genetic information it carries.

2. Two objects with equal masses collide head-on, both initially moving at the same speed. After the collision, they stick together. What is their final velocity?

• A. Zero
• B. Half their initial velocity
• C. Their initial velocity
• D. Twice their initial velocity

Correct answer: C

Rationale: In an inelastic collision where two objects stick together after colliding, momentum is conserved. Since the two objects have equal masses and equal initial velocities but opposite directions, their momenta cancel out. Therefore, after the collision, the combined mass will move at the same speed as the initial velocity, but in the direction of one of the objects. Choice A ('Zero') is incorrect because momentum is conserved, and the objects must move after the collision. Choice B ('Half their initial velocity') is incorrect as the final velocity is the same as the initial velocity due to momentum conservation. Choice D ('Twice their initial velocity') is incorrect as the final velocity cannot be twice the initial velocity based on the conservation of momentum principle.

3. What is the involuntary muscle tissue found in the walls of blood vessels and organs like the stomach and intestines?

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

Correct answer: C

Rationale: Smooth muscle is the correct answer. It is the involuntary muscle tissue found in the walls of blood vessels and organs like the stomach and intestines. Smooth muscle is responsible for various involuntary movements in the body, such as peristalsis in the digestive system and regulating blood flow in blood vessels. Skeletal muscle is voluntary and attached to bones for movement. Cardiac muscle is specific to the heart and not found in blood vessel walls or organs like the stomach and intestines. Striated muscle refers to both skeletal and cardiac muscle due to their striped appearance under a microscope, but it does not specifically describe the involuntary muscle tissue in the walls of blood vessels and organs as asked in the question.

4. Which of the following joints is an example of a hinge joint?

• A. Hip joint
• B. Elbow joint
• C. Shoulder joint
• D. Knee joint

Correct answer: B

Rationale: The correct answer is B: Elbow joint. A hinge joint allows movement primarily in one plane, enabling bending and straightening actions. The elbow joint specifically functions as a hinge joint, facilitating the bending and straightening of the arm. The other options, such as the hip joint (A), shoulder joint (C), and knee joint (D), are not examples of hinge joints as they allow movement in multiple planes with more complex motions.

5. Which of the following is NOT a function of the endocrine system?

• A. Regulating growth and development
• B. Maintaining blood sugar levels
• C. Controlling mood and emotions
• D. Facilitating digestion through muscle contractions

Correct answer: D

Rationale: The endocrine system is responsible for producing hormones that regulate various bodily functions such as growth, metabolism, mood, and more. Facilitating digestion through muscle contractions is primarily the role of the muscular and nervous systems, not the endocrine system. Therefore, option D is the correct answer as it does not align with the functions typically attributed to the endocrine system. Choices A, B, and C are functions that are indeed associated with the endocrine system, making them incorrect answers in the context of this question.

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