Nursing Elites

1. In an SN2 reaction, the rate of the reaction is affected by

• A. Only the concentration of the nucleophile
• B. Only the concentration of the electrophile
• C. Neither the concentration of the nucleophile nor the electrophile
• D. Both the concentration of the nucleophile and the electrophile

Correct answer: D

Rationale: In an SN2 reaction, the rate of the reaction is affected by both the concentration of the nucleophile and the electrophile. This is because in an SN2 reaction, the nucleophile directly attacks the electrophilic center, leading to the formation of the product. A higher concentration of nucleophile increases the chances of successful collisions with the electrophile, thereby increasing the reaction rate. Similarly, a higher concentration of the electrophile provides more reaction sites for the nucleophile to attack, also increasing the rate of the reaction. Therefore, both the nucleophile and electrophile concentrations play crucial roles in determining the rate of an SN2 reaction.

2. What is the meaning of the idiom "to bite off more than one can chew"?

• A. To be overly confident
• B. To take on more than one can handle
• C. To be easily discouraged
• D. To be meticulous in planning

Correct answer: B

Rationale: The idiom warns against undertaking a task exceeding one's capabilities.

3. What does the term "terminal velocity" refer to in physics?

• A. Maximum velocity reached by an object in free fall
• B. Velocity when the object is at rest
• C. nstantaneous velocity of an object
• D. Velocity only reached by heavy objects

Correct answer: a

Rationale: Terminal velocity is the constant velocity achieved by an object falling through the atmosphere when the force of air resistance equals the force of gravity.

4. The WBC (white blood cell) type responsible for the initial attack on pathogens is:

• A. Red blood cells
• B. Platelets
• C. Phagocytes
• D. Lymphocytes

Correct answer: C

Rationale: The correct answer is C: Phagocytes. Phagocytes are a type of white blood cell that plays a crucial role in the immune response by engulfing and destroying pathogens. They are the first line of defense against invading microorganisms, initiating the initial attack on pathogens. Red blood cells (option A) are responsible for carrying oxygen, not for immune responses. Platelets (option B) are involved in blood clotting. Lymphocytes (option D) are another type of white blood cell but are mainly responsible for specific immune responses rather than the initial attack on pathogens.

5. In the cardiovascular system, what is the primary function of red blood cells?

• A. To transport oxygen throughout the body.
• B. To fight infection and disease.
• C. To help regulate blood clotting.
• D. To remove waste products from the body.

Correct answer: A

Rationale: The correct answer is A: 'To transport oxygen throughout the body.' Red blood cells contain hemoglobin, a protein that binds to oxygen in the lungs and carries it to tissues throughout the body. This process is essential for cellular respiration, where oxygen is used to produce energy. Red blood cells do not fight infection (B), regulate blood clotting (C), or remove waste products (D); those functions are carried out by other components of the immune and circulatory systems.

6. The hormone responsible for milk production in the breasts after childbirth is:

• A. Estrogen
• B. Prolactin
• C. Oxytocin
• D. Relaxin

Correct answer: B

Rationale: The correct answer is B: Prolactin. Prolactin is the hormone responsible for milk production in the breasts after childbirth. It is produced by the pituitary gland and stimulates the alveoli in the breasts to produce milk. Estrogen plays a role in breast development during pregnancy but is not responsible for milk production. Oxytocin is responsible for the ejection of milk from the breasts during breastfeeding. Relaxin is a hormone that helps prepare the body for childbirth by relaxing the ligaments in the pelvis. Therefore, the hormone directly responsible for milk production after childbirth is prolactin.

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