Nursing Elites

1. During which phase of meiosis do chiasmata structures form?

• A. Prophase I
• B. Prophase II
• C. Metaphase I
• D. Metaphase II

Correct answer: A

Rationale: Chiasmata structures, where crossing over occurs, form during Prophase I of meiosis. This phase is characterized by homologous chromosomes pairing up and crossing over, leading to the exchange of genetic material between non-sister chromatids. Chiasmata are visible points of contact where genetic material has been exchanged, and they play a critical role in genetic diversity. Prophase II is the phase where chromosomes condense again in the second meiotic division, but chiasmata formation occurs in Prophase I. Metaphase I is the phase where homologous chromosomes align at the metaphase plate, not where chiasmata form. Metaphase II is the phase where replicated chromosomes align at the metaphase plate in the second meiotic division, but chiasmata formation occurs earlier in Prophase I.

2. Which type of immune cell does the human immunodeficiency virus (HIV) target and destroy?

• A. Neutrophils
• B. Macrophages
• C. Helper T cells
• D. Memory B cells

Correct answer: C

Rationale: HIV targets and destroys Helper T cells, which are vital for coordinating the immune response against infections. The destruction of Helper T cells weakens the immune system, leading to acquired immunodeficiency syndrome (AIDS). Neutrophils (Choice A) are primarily involved in acute inflammatory responses and fighting bacterial infections. Macrophages (Choice B) play a role in phagocytosis and antigen presentation but are not the primary target of HIV. Memory B cells (Choice D) are responsible for mounting a quicker and more robust antibody response upon re-exposure to a pathogen, but they are not the main target of HIV infection.

3. Which hormone is released by the adrenal glands in response to stress?

• A. Insulin
• B. Cortisol
• C. Adrenaline
• D. Glucagon

Correct answer: C

Rationale: Adrenaline is the correct answer. It is released by the adrenal glands in response to stress to prepare the body for the 'fight or flight' response. Adrenaline increases heart rate, dilates airways, and mobilizes energy stores to help the body deal with the perceived threat. Insulin (Choice A) is produced by the pancreas to regulate blood sugar levels, not in response to stress. Cortisol (Choice B) is another hormone released by the adrenal glands in response to stress, but it primarily helps regulate metabolism and immune response. Glucagon (Choice D) is also produced by the pancreas to increase blood sugar levels when they are low, not by the adrenal glands in response to stress.

4. At the peak of a baseball's trajectory, which of the following forces is acting on the ball?

• A. Only gravitational force
• B. Only the force of air resistance
• C. Both gravitational force and the force of air resistance
• D. Neither gravitational force nor the force of air resistance

Correct answer: A

Rationale: At the peak of a baseball's trajectory, the ball momentarily stops moving upwards before it starts to fall back down. During this moment of temporary rest, the only force acting on the ball is the gravitational force pulling it downward towards the Earth. The force of air resistance is negligible at this point because the ball is momentarily stationary, and air resistance requires motion to be significant. Therefore, the correct answer is that only the gravitational force is acting on the ball at the peak of its trajectory. Choices B, C, and D are incorrect because air resistance does not have a significant effect when the ball is at its peak and momentarily stationary.

5. How does the Pauli exclusion principle relate to the structure of the atom?

• A. It defines the maximum number of electrons allowed in each energy level.
• B. It explains why oppositely charged particles attract each other.
• C. It describes the wave-particle duality of electrons.
• D. It determines the arrangement of protons and neutrons in the nucleus.

Correct answer: A

Rationale: The Pauli exclusion principle states that no two electrons in an atom can have the same set of quantum numbers. This principle directly influences the structure of the atom by defining the maximum number of electrons allowed in each energy level. As a result, it helps determine the electron configuration and the arrangement of electrons in different orbitals within an atom. Choices B, C, and D are incorrect as they do not directly relate to the Pauli exclusion principle's specific impact on the electron distribution within an atom.

Similar Questions