Nursing Elites

1. What is the primary function of the myelin sheath that surrounds some axons in the nervous system?

• A. To initiate nerve impulses
• B. To transmit sensory information
• C. To speed up the transmission of nerve impulses
• D. To connect neurons at synapses

Correct answer: C

Rationale: The primary function of the myelin sheath is to speed up the transmission of nerve impulses. The myelin sheath acts as an insulating layer around the axon, allowing for faster conduction of electrical impulses along the nerve fiber. This insulation prevents the electrical signal from dissipating or 'leaking' out, which helps in the rapid and efficient transmission of nerve impulses along the axon. Choice A is incorrect because the myelin sheath does not initiate nerve impulses; it helps in conducting them. Choice B is incorrect as the myelin sheath's main role is not in transmitting sensory information but rather in facilitating the transmission of nerve impulses. Choice D is incorrect because the myelin sheath's function is not to connect neurons at synapses; instead, it is primarily involved in enhancing the speed of nerve impulse transmission.

2. Which of the following terms means close to the trunk of the body?

• A. Superficial
• B. Sagittal
• C. Proximal
• D. Distal

Correct answer: C

Rationale: The term 'proximal' means situated close to the point of attachment or the center of the body, such as close to the trunk. In anatomical terms, proximal is used to describe locations that are closer to the body's center or point of reference. 'Superficial' refers to something situated near the surface, 'sagittal' refers to a plane that divides the body into left and right portions, and 'distal' refers to a position away from the center or point of reference. Therefore, 'proximal' is the correct term to indicate a position close to the trunk of the body.

3. Deuterium, a stable isotope of hydrogen, has a nucleus containing:

• A. A single proton
• B. A proton and a neutron
• C. Two protons and an electron
• D. Two neutrons

Correct answer: B

Rationale: Deuterium, as an isotope of hydrogen, has an atomic number of 1 and a mass number of 2. The nucleus of deuterium contains one proton (as in all hydrogen atoms) and one neutron, totaling 2 nucleons in the nucleus. Therefore, the correct answer is that deuterium's nucleus contains a proton and a neutron. Choices A, C, and D are incorrect. Deuterium is not just a single proton (A), doesn't have two protons and an electron (C), and doesn't contain two neutrons (D). The correct composition of deuterium's nucleus is one proton and one neutron.

4. 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.

5. In a scientific investigation, what is the first step?

• A. Analysis of results
• B. Drawing conclusions
• C. Formation of hypothesis
• D. Performing the experiment

Correct answer: C

Rationale: The correct answer is C: Formation of hypothesis. In a scientific investigation, forming a hypothesis is the initial step. A hypothesis is an educated guess or prediction based on existing knowledge and observations. It helps guide the experiment and provides a direction for the research process. Without a hypothesis, there is no specific aim or goal for the experiment. Choices A, B, and D are incorrect because they occur after the formation of a hypothesis. Analysis of results and drawing conclusions typically come after the experiment has been conducted, while performing the experiment is done to test the hypothesis formed at the beginning of the investigation.

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