Nursing Elites

1. Which statement accurately describes cytokinesis in animal cells?

• A. Which statement accurately describes cytokinesis in animal cells?
• B. A cell plate forms in the center of the dividing cell, eventually separating the cytoplasm into two daughter cells.
• C. A cell plate forms in the center of the dividing cell, eventually separating the cytoplasm into two daughter cells.
• D. The nucleus elongates and pulls apart, physically dividing the cytoplasm into two.

Correct answer: B

Rationale: Rationale: A) This statement is a duplicate of option C and does not accurately describe cytokinesis in animal cells. B) In animal cells, during cytokinesis, a cleavage furrow forms in the center of the dividing cell. This furrow deepens and eventually pinches the cytoplasm into two daughter cells. This process is distinct from plant cells, where a cell plate forms. C) This statement is a duplicate of option A and does not accurately describe cytokinesis in animal cells. D) This statement describes the process of nuclear division (mitosis) rather than cytokinesis, which is the division of the cytoplasm.

2. Peppered moths in England came in two color variations – light and dark. After the Industrial Revolution, the population shifted towards more dark moths. This is an example of:

• A. Artificial selection (humans breeding for desired traits)
• B. Natural selection acting on pre-existing variation
• C. Punctuated equilibrium (rapid bursts of evolution)
• D. Lamarckism (inheritance of acquired characteristics)

Correct answer: B

Rationale: Rationale: The phenomenon of peppered moths in England shifting towards more dark moths after the Industrial Revolution is a classic example of natural selection acting on pre-existing variation. Before the Industrial Revolution, light-colored moths were better camouflaged against lichen-covered tree trunks, which were common in the environment. However, with the increase in industrial pollution, the tree trunks became darker due to soot, making dark-colored moths better camouflaged and less likely to be eaten by predators. As a result, the population shifted towards more dark moths over time. This change in the moth population was driven by the selective pressure of predation, demonstrating the process of natural selection favoring individuals with traits that provide a survival advantage in a changing environment.

3. What is the difference between exhalation (expiration) and inhalation (inspiration)?

• A. Exhalation involves active muscle contraction, while inhalation is passive.
• B. Inhalation brings in oxygen-rich air, while exhalation releases oxygen-depleted air.
• C. Exhalation occurs through the nose only, while inhalation can occur through the nose or mouth.
• D. Inhalation warms and humidifies air, while exhalation cools and dries air.

Correct answer: B

Rationale: Option B is the correct answer because inhalation is the process of breathing in, where the diaphragm and intercostal muscles contract to expand the chest cavity, allowing air to enter the lungs. This air is rich in oxygen, which is essential for cellular respiration. On the other hand, exhalation is the process of breathing out, where the diaphragm and intercostal muscles relax, causing the chest cavity to decrease in size and air to be expelled from the lungs. This air is depleted of oxygen as it has been used up during cellular respiration. Understanding the difference between inhaling oxygen-rich air and exhaling oxygen-depleted air is crucial for comprehending the respiratory system's function and the exchange of gases in the body.

4. Which of the following phases of mitosis is characterized by the separation of sister chromatids and their movement to opposite poles?

• A. Metaphase
• B. Anaphase
• C. Anaphase
• D. Cytokinesis

Correct answer: B

Rationale: Rationale: During anaphase of mitosis, the sister chromatids, which are duplicated copies of a chromosome, separate and move towards opposite poles of the cell. This movement is facilitated by the shortening of microtubules attached to the chromatids. As a result, each pole of the cell receives a complete set of chromosomes, ensuring that the daughter cells produced after cell division will have the correct number of chromosomes. Metaphase is characterized by the alignment of chromosomes at the cell's equator, not their separation. Telophase is the phase following anaphase, where the separated chromatids reach the opposite poles and nuclear envelopes start to form around them. Cytokinesis is the final stage of cell division, where the cytoplasm is divided to form two separate daughter cells.

5. What are the differences between RNA and DNA?

• A. Both have the same structure and function.
• B. RNA is single-stranded, while DNA is double-stranded.
• C. RNA contains ribose sugar, while DNA contains deoxyribose sugar.
• D. RNA has adenine and guanine, while DNA has thymine and cytosine.

Correct answer: B

Rationale: Rationale: A) This statement is incorrect. RNA and DNA have different structures and functions. RNA is involved in protein synthesis and other cellular processes, while DNA stores genetic information. B) This statement is correct. RNA is typically single-stranded, while DNA is double-stranded, forming a double helix structure. C) This statement is correct. RNA contains ribose sugar in its backbone, while DNA contains deoxyribose sugar. D) This statement is incorrect. RNA contains adenine, guanine, cytosine, and uracil, while DNA contains adenine, guanine, cytosine, and thymine.

6. What is the relationship between force and acceleration according to Newton's second law?

• A. Force is directly proportional to acceleration
• B. orce is inversely proportional to acceleration
• C. Force has no relation to acceleration
• D. Force causes deceleration, not acceleration

Correct answer: A

Rationale: According to Newton's second law of motion, the acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass. This relationship is mathematically expressed as F = ma, where F represents force, m represents mass, and a represents acceleration. Therefore, an increase in force will result in a proportional increase in acceleration, supporting the statement that force is directly proportional to acceleration.

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