Nursing Elites

1. Which of the following is NOT a primary producer in an ecosystem?

• A. Grass
• B. Deer
• C. Algae
• D. Mushroom

Correct answer: B

Rationale: Rationale: - A) Grass: Grass is a primary producer because it can photosynthesize and convert sunlight into energy, making it the base of the food chain. - B) Deer: Deer are consumers that feed on primary producers like grass, so they are not primary producers themselves. - C) Algae: Algae are primary producers that can photosynthesize and produce energy from sunlight. - D) Mushroom: Mushrooms are decomposers that break down organic matter, so they are not primary producers.

2. 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.

3. When ice melts, it undergoes a…

• A. Chemical change
• B. Physical change
• C. Nuclear change
• D. Radioactive decay

Correct answer: B

Rationale: Melting is a change in physical state, not a change in the chemical composition of the ice.

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 hormone, produced by the adrenal glands, is essential for the regulation of electrolyte balance, particularly sodium and potassium, in the body?

• A. Aldosterone
• B. Epinephrine
• C. Cortisol
• D. Insulin

Correct answer: A

Rationale: The correct answer is A: Aldosterone. Aldosterone is a hormone produced by the adrenal glands that plays a crucial role in regulating electrolyte balance, especially sodium and potassium levels in the body. It acts on the kidneys to increase the reabsorption of sodium and excretion of potassium, which helps to maintain proper fluid balance and blood pressure. Epinephrine (B) is involved in the 'fight or flight' response, cortisol (C) is a stress hormone, and insulin (D) regulates blood sugar levels, but neither of these hormones primarily regulates electrolyte balance like aldosterone does.

6. Which of the following is NOT a mechanism that can directly cause evolution by natural selection?

• A. Mutations in genes
• B. Differential survival and reproduction based on traits
• C. Inheritance of acquired characteristics (like strong muscles from working out)
• D. Competition for resources in an environment

Correct answer: C

Rationale: Rationale: A) Mutations in genes can introduce new genetic variations into a population, which can be acted upon by natural selection. B) Differential survival and reproduction based on traits is a key component of natural selection, as individuals with advantageous traits are more likely to survive and pass on their genes to the next generation. C) Inheritance of acquired characteristics, also known as Lamarckism, is not a mechanism of evolution by natural selection. Traits acquired during an individual's lifetime (such as strong muscles from working out) are not passed on to offspring. D) Competition for resources in an environment can drive natural selection by favoring individuals with traits that help them better compete for limited resources. Therefore, the correct answer is C) Inheritance of acquired characteristics (like strong muscles from working out), as it is not a mechanism that can directly cause evolution by natural selection.

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