Nursing Elites

1. A keystone species plays a critical role in an ecosystem because its removal would:

• A. Lead to a decrease in competition among other species
• B. Cause a slight increase in primary productivity
• C. Have a minimal impact on the overall ecosystem structure
• D. Disrupt the food web and cause cascading effects on other populations

Correct answer: D

Rationale: Rationale: Keystone species are species that have a disproportionately large effect on their environment relative to their abundance. They play a critical role in maintaining the structure and function of an ecosystem. If a keystone species is removed from an ecosystem, it can disrupt the food web by causing imbalances in predator-prey relationships. This disruption can lead to cascading effects on other populations within the ecosystem, potentially causing population declines or even extinctions. Therefore, the removal of a keystone species would have significant impacts on the overall ecosystem structure, making option D the correct answer.

2. The endocrine system communicates through chemical messengers called:

• A. Enzymes
• B. Hormones
• C. Antibodies
• D. Neurons

Correct answer: B

Rationale: The correct answer is B: Hormones. The endocrine system communicates through hormones, which are chemical messengers produced by various glands in the body. These hormones are released into the bloodstream and travel to target organs or tissues to regulate a wide range of bodily functions. Enzymes (A) are biological molecules that catalyze chemical reactions, not chemical messengers for communication within the body. Antibodies (C) are involved in the immune system's response to foreign substances. Neurons (D) are part of the nervous system and communicate through electrical impulses rather than chemical messengers like hormones.

3. What is the function of the pituitary gland?

• A. Produces hormones that regulate growth and metabolism
• B. Filters blood and removes waste products
• C. Stores and releases bile
• D. Produces red blood cells

Correct answer: A

Rationale: The pituitary gland is often referred to as the "master gland" because it controls the activity of many other endocrine glands in the body. It is located at the base of the brain and produces a variety of hormones that regulate various bodily functions, including growth, metabolism, reproduction, and blood pressure.

4. Which test is commonly used to assess kidney function?

• A. Complete blood count (CBC)
• B. Blood sugar test
• C. Urinalysis
• D. Creatinine clearance test

Correct answer: D

Rationale: The correct answer is D: Creatinine clearance test. This test is commonly used to assess kidney function by measuring how well the kidneys are filtering waste products like creatinine from the blood. Creatinine is a waste product produced by muscles and is normally filtered out by the kidneys. A high level of creatinine in the blood can indicate reduced kidney function. Options A, B, and C are not specifically used to assess kidney function. A complete blood count (CBC) measures different components of the blood like red blood cells, white blood cells, and platelets. A blood sugar test is used to measure glucose levels in the blood. Urinalysis is a test that analyzes the urine for various substances like proteins, glucose, and blood cells, but it is not the primary test for assessing kidney function.

5. When an atom gains or loses electrons, it becomes a(n):

• A. Molecule
• B. Isotope
• C. Ion
• D. Compound

Correct answer: C

Rationale: Gaining or losing electrons alters the atom's electron count and charge, creating a positively or negatively charged ion.

6. A bag contains 5 red marbles and 7 blue marbles. If you draw a marble without looking, what is the probability it will be red?

• A. 1/4
• B. 1/3
• C. 1/2
• D. 2/3

Correct answer: A

Rationale: Divide the number of red marbles (5) by the total number of marbles (12) to get 1/3 probability.

Similar Questions