Nursing Elites

1. Are red hair and a height of six feet part of an individual's genotype or phenotype?

• A. Red hair is part of the phenotype; height is part of the genotype.
• B. Red hair is part of the genotype; height is part of the phenotype.
• C. Both characteristics describe his genotype.
• D. Both characteristics describe his phenotype.

Correct answer: D

Rationale: In the context of genetics, genotype refers to an individual's genetic makeup, while phenotype refers to the observable characteristics resulting from the interaction of the genotype with the environment. Red hair and a height of six feet are observable characteristics, making them part of the individual's phenotype. Therefore, both red hair and height are aspects of the individual's phenotype. Choices A and B are incorrect as they incorrectly assign one characteristic to the genotype and the other to the phenotype, which is not accurate. Choice C is incorrect as it states that both characteristics describe the genotype, which is inaccurate as they are observable traits. The correct answer is D, as both red hair and height are observable traits or characteristics, falling under the definition of phenotype in genetics.

2. What is the primary function of ribosomes in the cell?

• A. To synthesize lipids and other cellular components
• B. To package and transport proteins
• C. To break down macromolecules
• D. To translate mRNA into proteins

Correct answer: D

Rationale: Ribosomes are cellular organelles responsible for protein synthesis. They read the genetic information encoded in messenger RNA (mRNA) and use this information to assemble amino acids into a specific sequence, forming a protein. This process is known as translation and is essential for the production of proteins that carry out various functions in the cell. Options A, B, and C are incorrect as they do not accurately describe the primary function of ribosomes. Choice A is incorrect because the synthesis of lipids and other cellular components is not the primary function of ribosomes. Choice B is incorrect as packaging and transporting proteins are functions typically associated with the endoplasmic reticulum and Golgi apparatus. Choice C is incorrect because ribosomes do not break down macromolecules; instead, they are involved in building proteins from amino acids.

3. What is the balanced chemical equation for the reaction between sulfuric acid (H2SO4) and potassium hydroxide (KOH)?

• A. H2SO4 + KOH → K2SO4 + H2O
• B. 2H2SO4 + 2KOH → 2K2SO4 + 2H2O
• C. H2SO4 + 2KOH → K2SO4 + 2H2O
• D. H2SO4 + 2KOH → K2SO4 + H2O

Correct answer: C

Rationale: When sulfuric acid (H2SO4) reacts with potassium hydroxide (KOH), it forms potassium sulfate (K2SO4) and water (H2O). To balance the equation, 2 KOH molecules are required to react with 1 H2SO4 molecule, resulting in 1 K2SO4 molecule and 2 H2O molecules. Therefore, the balanced chemical equation is H2SO4 + 2KOH → K2SO4 + 2H2O, which corresponds to option C. Choice A is incorrect because it does not account for the correct stoichiometry between the reactants and products. Choice B incorrectly doubles all the molecules in the reaction, leading to an unbalanced equation. Choice D incorrectly balances the equation with 1 KOH molecule instead of the required 2 KOH molecules, making it unbalanced. Thus, option C is the correct balanced chemical equation for the reaction between sulfuric acid and potassium hydroxide.

4. What phenomenon occurs when two identical waves are perfectly aligned and reinforce each other?

• A. Refraction
• B. Reflection
• C. Diffraction
• D. Constructive interference

Correct answer: D

Rationale: Constructive interference occurs when two identical waves are perfectly aligned and reinforce each other. This results in an increase in the overall amplitude of the wave. Refraction refers to the bending of waves as they pass from one medium to another, reflection is the bouncing back of waves when they encounter a boundary, and diffraction is the bending of waves around obstacles and openings. In this scenario, the waves are not changing direction or bending but rather combining to produce a wave with a larger amplitude, which is characteristic of constructive interference.

5. Myelin sheath is a fatty substance that insulates and protects the long extensions of some nerve cells. It is produced by:

• A. Schwann cells
• B. Astrocytes
• C. Neurons
• D. Oligodendrocytes

Correct answer: A

Rationale: Schwann cells are indeed responsible for producing the myelin sheath in the peripheral nervous system. These cells wrap around axons to form the myelin sheath, which enhances the speed of nerve impulse conduction. In the central nervous system, oligodendrocytes are responsible for producing the myelin sheath. Astrocytes provide support and maintenance functions for neurons, while neurons are the nerve cells themselves and do not produce myelin. Therefore, the correct answer is Schwann cells as they are specifically involved in myelin production in the peripheral nervous system.

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