Nursing Elites

1. How does the structure of centromeres contribute to chromosome movement during mitosis?

• A. The centromere provides a binding site for spindle fibers, allowing chromosomes to be attached and manipulated.
• B. The centromere serves as a dividing point between sister chromatids, ensuring their separation during anaphase.
• C. The centromere maintains chromosome stability by preventing chromosomal breaks and rearrangements.
• D. The centromere plays a role in DNA replication, ensuring accurate copying of the genetic material.

Correct answer: A

Rationale: A) The centromere provides a binding site for spindle fibers, which are microtubules that help move chromosomes during cell division. This attachment allows the chromosomes to be pulled towards opposite poles of the cell during mitosis. Therefore, the structure of centromeres directly contributes to chromosome movement during mitosis by facilitating the attachment and manipulation of chromosomes by the spindle fibers. B) While the centromere does serve as a dividing point between sister chromatids, ensuring their separation during anaphase, this function is more related to the segregation of chromosomes rather than their movement. C) The centromere does play a role in maintaining chromosome stability by ensuring proper chromosome segregation, but it is not primarily responsible for preventing chromosomal breaks and rearrangements. D) The centromere is not directly involved in DNA replication. Its main function is

2. Which structure contains the genetic material (DNA) of the cell?

• A. Cytoplasm
• B. Nucleus
• C. Cell wall (only present in plant cells)
• D. Golgi apparatus

Correct answer: B

Rationale: The nucleus is the organelle that contains the genetic material (DNA) of the cell. It acts as the control center of the cell, regulating gene expression and coordinating cellular activities. The cytoplasm is the fluid-filled space within the cell where organelles are suspended, but it does not contain the genetic material. The cell wall is a rigid structure found in plant cells that provides support and protection, but it does not house the DNA. The Golgi apparatus is involved in processing and packaging proteins for secretion, but it does not contain the genetic material of the cell.

3. What causes stretch marks?

• A. The epidermis layer becomes inflamed
• B. The dermis layer becomes inflamed
• C. The dermis layer tears due to rapid stretching
• D. Sebaceous glands become clogged

Correct answer: C

Rationale: Stretch marks occur when the dermis layer tears due to rapid stretching of the skin. This tearing leads to the appearance of stretch marks, which are often red or purple at first and then fade to a silvery-white color over time. Inflammation of the dermis or clogging of sebaceous glands are not directly related to the formation of stretch marks. Therefore, choices A, B, and D are incorrect as they do not describe the actual cause of stretch marks.

4. Which law of motion explains the behavior of rockets in space?

• A. Newton's First Law
• B. Newton's Second Law
• C. Newton's Third Law
• D. None of the above

Correct answer: C

Rationale: The correct answer is Newton's Third Law. Newton's Third Law states that for every action, there is an equal and opposite reaction. In the case of rockets in space, the action is the expulsion of gas from the rocket engines, and the reaction is the forward motion of the rocket. This law explains how rockets are able to propel themselves forward in the vacuum of space. Choices A and B are incorrect because Newton's First Law (inertia) and Second Law (F=ma) do not directly explain the behavior of rockets in space. Choice D is incorrect as Newton's Third Law specifically addresses the principle behind rockets' motion in space.

5. Which of the following organs is part of the central nervous system?

• A. Heart
• B. Brain
• C. Liver
• D. Lungs

Correct answer: B

Rationale: The correct answer is B: Brain. The brain is a vital organ that is part of the central nervous system, along with the spinal cord. It plays a crucial role in processing information, controlling body functions, and coordinating responses to stimuli. The heart, liver, and lungs are not part of the central nervous system; they belong to the cardiovascular and respiratory systems, respectively. The heart is part of the cardiovascular system, responsible for pumping blood throughout the body. The liver is part of the digestive system, involved in processes like detoxification and metabolism. The lungs are part of the respiratory system, facilitating the exchange of oxygen and carbon dioxide during breathing.

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