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: 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. What is an example of a fibrous protein?

• A. Insulin
• B. Keratin
• C. Hemoglobin
• D. Collagen

Correct answer: D

Rationale: Rationale: A) Insulin is a hormone, not a fibrous protein. Insulin is produced in the pancreas and is involved in regulating blood sugar levels. B) Keratin is a fibrous structural protein found in hair, nails, and the outer layer of skin. It provides strength and protection. C) Hemoglobin is a globular protein found in red blood cells that is responsible for carrying oxygen from the lungs to the rest of the body. It is not a fibrous protein. D) Collagen is a fibrous protein that is the main component of connective tissues such as tendons, ligaments, and skin. It provides strength and structure to these tissues.

3. A person pushes a box across a floor with a constant force. The box eventually comes to a stop due to friction. What happens to the work done by the person?

• A. It increases as the box moves further.
• B. It decreases as the box slows down.
• C. It remains constant throughout the motion.
• D. It becomes zero once the box stops.

Correct answer: C

Rationale: Work is defined as force multiplied by distance, and as long as the force remains constant, the work done increases proportionally to the distance moved, even if the box slows down due to friction.

4. Which process involves the body's natural defense against inhaled dust and allergens?

• A. Cellular respiration
• B. Gas exchange
• C. Ciliary action
• D. Bronchoconstriction

Correct answer: C

Rationale: The correct answer is C: Ciliary action. Cilia are tiny hair-like structures lining the respiratory tract that help trap and remove inhaled dust and allergens. When these particles are trapped in the mucus produced by the cilia, the cilia beat in a coordinated fashion to move the mucus and its trapped particles out of the respiratory system, preventing them from reaching the lungs. Cellular respiration (A) is the process by which cells generate energy from nutrients, not a defense mechanism. Gas exchange (B) refers to the exchange of oxygen and carbon dioxide in the lungs, not a defense mechanism. Bronchoconstriction (D) is the narrowing of the airways, often in response to triggers like allergens, but it is not the body's natural defense mechanism against inhaled dust and allergens.

5. Which sentence uses the passive voice correctly?

• A. The letter was written by Mary.
• B. John built the house.
• C. She gave the flowers to him.
• D. They were eating dinner.

Correct answer: A

Rationale: Option a clearly identifies the object (letter) acted upon and the agent (Mary) performing the action in the passive voice.

6. Aromatic compounds

• A. Contain a ring structure with alternating single and double bonds
• B. Readily undergo addition reactions
• C. Are easily broken down by water
• D. Do not contain any pi (Ï€) bonds

Correct answer: A

Rationale: The correct answer is A: 'Aromatic compounds contain a ring structure with alternating single and double bonds.' Aromatic compounds exhibit a special stability due to the delocalization of pi electrons within the ring, known as resonance. This resonance occurs because of the alternating single and double bonds in the ring structure, making them less reactive towards addition reactions compared to alkenes, which have only double bonds. This stability also makes aromatic compounds less likely to be easily broken down by water, as they are relatively inert in many chemical reactions. Therefore, aromatic compounds do contain pi (π) bonds due to the presence of the alternating single and double bonds in their ring structure.

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