Nursing Elites

1. B cells in the immune system are responsible for:

• A. Directly attacking and engulfing pathogens
• B. Producing antibodies specific to a pathogen
• C. Destroying infected body cells
• D. All of the above

Correct answer: B

Rationale: B cells in the immune system are responsible for producing antibodies specific to a pathogen. This is because B cells are a type of white blood cell that play a crucial role in the adaptive immune response. When a B cell encounters a specific pathogen, it differentiates into plasma cells that produce antibodies targeted against that particular pathogen. These antibodies then tag the pathogen for destruction by other immune cells. B cells do not directly attack and engulf pathogens like phagocytes, nor do they destroy infected body cells like cytotoxic T cells. Therefore, option B is the correct answer as it accurately reflects the primary function of B cells in the immune system.

2. What is the work done by a force of 20 N acting on an object that moves 5 meters in the direction of the force?

• A. 100 Joules (J)
• B. 25 Joules (J)
• C. 4 Joules (J)
• D. Work cannot be determined without knowing the object's mass.

Correct answer: A

Rationale: Work is defined as the force applied multiplied by the distance moved in the direction of the force. Work = force x distance = 20 N x 5 m = 100 J.

3. The muscular chamber of the heart that receives blood from the body and pumps it to the lungs is the:

• A. Right atrium
• B. Left atrium
• C. Right ventricle
• D. Left ventricle

Correct answer: C

Rationale: The correct answer is C: Right ventricle. The right ventricle receives deoxygenated blood from the body and pumps it to the lungs for oxygenation. The right atrium receives deoxygenated blood from the body and passes it to the right ventricle. The left atrium receives oxygenated blood from the lungs and passes it to the left ventricle. The left ventricle then pumps oxygenated blood to the rest of the body. Understanding the flow of blood through the heart chambers is essential for grasping the functions of each chamber in the circulatory system.

4. Which of the following hormones is produced by the adrenal medulla and prepares the body for a stressful situation?

• A. Testosterone
• B. Cortisol
• C. Epinephrine (adrenaline)
• D. Growth hormone

Correct answer: C

Rationale: The correct answer is C: Epinephrine (adrenaline). Epinephrine is produced by the adrenal medulla and is responsible for preparing the body for a stressful situation, often referred to as the 'fight or flight' response. Testosterone is a hormone produced by the testes in males and in smaller amounts by the ovaries in females, responsible for male sexual characteristics. Cortisol is produced by the adrenal cortex and plays a role in regulating metabolism and immune response. Growth hormone is produced by the pituitary gland and is essential for growth, cell repair, and metabolism. Therefore, epinephrine is the hormone specifically produced by the adrenal medulla to prepare the body for stress.

5. Which of the following types of muscle tissue is found attached to bones and allows for voluntary movement?

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

Correct answer: C

Rationale: The correct answer is C: Skeletal muscle. Skeletal muscle is the type of muscle tissue that is attached to bones and allows for voluntary movement. This type of muscle is under conscious control, meaning we can choose to contract or relax these muscles to produce movement. Smooth muscle (option A) is found in the walls of internal organs and is not under voluntary control. Cardiac muscle (option B) is found in the heart and also functions involuntarily. Connective tissue (option D) primarily provides support and structure to the body but does not directly enable movement like skeletal muscle does.

6. What is the significance of the nuclear envelope breaking down during mitosis?

• A. It allows the chromosomes to condense and become visible.
• B. It allows the spindle apparatus to form and attach to the chromosomes.
• C. It allows the sister chromatids to separate.
• D. It allows the nuclear material to be evenly distributed to the daughter cells.

Correct answer: B

Rationale: Rationale: A) The breakdown of the nuclear envelope does not directly cause the chromosomes to condense and become visible. Chromosome condensation is a separate process that occurs before mitosis begins. B) The breakdown of the nuclear envelope is crucial for the formation of the spindle apparatus, a structure made of microtubules that helps separate the chromosomes during cell division. The spindle apparatus attaches to the chromosomes and helps move them to opposite poles of the cell. C) The separation of sister chromatids occurs during anaphase, which is facilitated by the spindle apparatus. The breakdown of the nuclear envelope is not directly involved in this process. D) The even distribution of nuclear material to daughter cells is achieved through the movement of chromosomes by the spindle apparatus, which is made possible by the breakdown of the nuclear envelope.

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