Nursing Elites

1. What is the fatty substance that coats axons to insulate, protect, and speed up impulses?

• A. Myelin
• B. Dendrite
• C. Neuron
• D. Synapse

Correct answer: A

Rationale: The correct answer is 'Myelin.' Myelin is a fatty substance that functions as an insulator for axons, providing protection and enhancing the speed of electrical impulses along neurons. This insulation is essential for ensuring efficient and rapid communication within the nervous system. Choices B, C, and D are incorrect. Dendrites are branched extensions of a neuron that receive signals, neurons are the basic building blocks of the nervous system that transmit information, and synapses are the junctions between neurons where communication occurs.

2. What is the main function of the endoplasmic reticulum (ER) in the cell?

• A. To synthesize and transport proteins and lipids
• B. To package and transport proteins
• C. To break down macromolecules
• D. To store genetic material

Correct answer: A

Rationale: The endoplasmic reticulum (ER) is a network of membranes within the cell that plays a crucial role in protein and lipid synthesis. It consists of two types: rough ER, which is studded with ribosomes and involved in protein synthesis, and smooth ER, which is involved in lipid synthesis and detoxification. The ER's main function is to synthesize proteins and lipids, not just package and transport them. While the ER is involved in transporting these synthesized proteins and lipids to other parts of the cell or outside the cell, its primary role is in their synthesis. Breaking down macromolecules is primarily the function of lysosomes, which are membrane-bound organelles containing enzymes for digestion. Storing genetic material is the function of the nucleus, which houses the cell's DNA. The ER is not involved in storing genetic material.

3. What are the fluid-filled sacs that cushion the brain within the skull called?

• A. Meninges
• B. Cerebrospinal fluid
• C. Dura mater
• D. Arachnoid mater

Correct answer: B

Rationale: The correct answer is B, cerebrospinal fluid. Cerebrospinal fluid acts as a shock absorber, protecting the brain from impact and providing nutrients to brain cells. Meninges are the three protective layers of tissue that surround the brain and spinal cord. Dura mater and arachnoid mater are specific layers of the meninges, not the fluid-filled sacs that cushion the brain.

4. What is the basic structure of an atom?

• A. Protons, neutrons, electrons
• B. Protons, electrons, ions
• C. Neutrons, electrons, ions
• D. Protons, ions, molecules

Correct answer: A

Rationale: The basic structure of an atom consists of protons and neutrons located in the nucleus, with electrons orbiting around the nucleus in specific energy levels or shells. Protons carry a positive charge, neutrons carry no charge, and electrons carry a negative charge. This arrangement maintains the overall neutrality of the atom, with the number of protons equaling the number of electrons. Therefore, the correct answer is 'Protons, neutrons, electrons.' Choices B, C, and D are incorrect as they do not accurately represent the fundamental components of an atom. Choice B includes 'ions,' which are charged particles, not fundamental components of an atom. Choice C includes 'ions' and lacks protons. Choice D includes 'ions' and 'molecules,' which are not part of the basic structure of an atom.

5. 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.

Similar Questions