Nursing Elites

1. Which of the following is an example of stabilizing selection?

• A. Selection that favors extreme traits in a population
• B. Selection that removes individuals with extreme traits
• C. Selection that maintains the current average trait in a population
• D. Selection that favors one specific trait over all others

Correct answer: C

Rationale: - Stabilizing selection is a type of natural selection that favors the intermediate variants in a population, while selecting against the extreme traits. This results in the maintenance of the current average trait in the population. - Option A is incorrect because stabilizing selection does not favor extreme traits; instead, it favors the average trait. - Option B is incorrect because stabilizing selection does not remove individuals with extreme traits; it acts against extreme traits by favoring the intermediate variants. - Option D is incorrect because stabilizing selection does not favor one specific trait over all others; it favors the average trait by selecting against extreme traits.

2. Which type of bond is exemplified by KCl?

• A. Ionic bond
• B. Covalent bond
• C. Hydrogen bond
• D. Polar covalent bond

Correct answer: A

Rationale: KCl exemplifies an ionic bond. In an ionic bond, electrons are transferred between atoms, resulting in the formation of ions. In the case of KCl, potassium (K) donates an electron to chlorine (Cl), leading to the creation of K+ and Cl- ions, which are held together by electrostatic forces of attraction. Choice B, covalent bond, is incorrect because covalent bonds involve the sharing of electrons between atoms, not the transfer of electrons as seen in KCl. Choice C, hydrogen bond, is incorrect as hydrogen bonds are a type of intermolecular force, not a bond formed by the transfer or sharing of electrons between atoms. Choice D, polar covalent bond, is also incorrect because although it involves the sharing of electrons with an unequal distribution of charge, KCl is a clear example of ionic bonding where electrons are completely transferred.

3. A routine urinalysis is a common diagnostic test. What does a urinalysis typically evaluate?

• A. Blood sugar levels
• B. Presence of white blood cells (indicating possible infection)
• C. Kidney function
• D. All of the above

Correct answer: D

Rationale: A routine urinalysis evaluates multiple components of urine, including blood sugar levels, the presence of white blood cells indicating a possible infection, and kidney function. Blood sugar levels are assessed to monitor for conditions like diabetes. The presence of white blood cells is checked to detect possible urinary tract infections. Kidney function is evaluated by assessing markers like creatinine and protein levels. Therefore, all of the above options are typically evaluated in a urinalysis, making choice D the correct answer.

4. Which type of blood cell is primarily responsible for fighting infections?

• A. Red blood cell
• B. White blood cell
• C. Platelet
• D. Plasma

Correct answer: B

Rationale: The correct answer is B: White blood cell. White blood cells are the primary cells responsible for fighting infections and foreign invaders in the body. Red blood cells carry oxygen to tissues, platelets help in blood clotting to prevent excessive bleeding, and plasma is the liquid component of blood that carries cells and nutrients. White blood cells, also known as leukocytes, play a crucial role in the immune system by identifying and destroying pathogens, such as bacteria, viruses, and other harmful substances. Therefore, they are the key players in the body's defense against infections, making them the correct answer in this scenario. While red blood cells, platelets, and plasma have essential functions in the body, they are not primarily responsible for combating infections like white blood cells.

5. Which neurotransmitter is associated with pleasure, reward, and motivation, and is often implicated in conditions such as addiction?

• A. Acetylcholine
• B. Dopamine
• C. Serotonin
• D. GABA (Gamma-aminobutyric acid)

Correct answer: B

Rationale: Dopamine is the neurotransmitter associated with pleasure, reward, and motivation. It plays a crucial role in the brain's reward system and is often implicated in conditions such as addiction. Acetylcholine is involved in muscle movement and memory, serotonin is linked to mood regulation, and GABA is an inhibitory neurotransmitter that helps reduce neuronal excitability. Therefore, the correct answer is dopamine as it aligns with the neurotransmitter functions related to pleasure, reward, and motivation, distinct from the roles of acetylcholine, serotonin, and GABA.

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