Nursing Elites

1. Which type of cells make up the myelin sheaths?

• A. Glial cells.
• B. Dendrites.
• C. Melanocytes.
• D. Squamous cells.

Correct answer: A

Rationale: The correct answer is A: Glial cells. Glial cells are responsible for producing the myelin sheaths that surround and insulate nerve cells in the central and peripheral nervous systems. Schwann cells in the peripheral nervous system and oligodendrocytes in the central nervous system are types of glial cells that form the myelin sheaths. Choice B, dendrites, are not involved in forming myelin sheaths; they are extensions of neurons that receive signals. Choice C, melanocytes, are cells responsible for producing melanin, not myelin. Choice D, squamous cells, are flat epithelial cells found in various tissues but are not involved in myelin sheath formation.

2. When a blockage forms in a coronary artery, reducing blood flow to the heart muscle, this condition is called:

• A. Atherosclerosis
• B. Myocardial infarction
• C. Angina pectoris
• D. Heart murmur

Correct answer: B

Rationale: A myocardial infarction, commonly known as a heart attack, occurs when a blockage forms in a coronary artery, leading to reduced blood flow to the heart muscle. Atherosclerosis refers to the buildup of plaque in the arteries, which can lead to blockages but is not the name for this specific condition. Angina pectoris is chest pain or discomfort due to inadequate blood supply to the heart muscle, which is a precursor to a heart attack but not the name for this condition. A heart murmur is an abnormal sound heard during a heartbeat, often due to turbulent blood flow, and is not related to a blockage in a coronary artery.

3. What is the relationship between the frequency and period of a wave?

• A. They are unrelated
• B. Frequency = Period
• C. Frequency = 1/Period
• D. Period = 1/Frequency

Correct answer: D

Rationale: The correct relationship between frequency and period of a wave is that Period = 1/Frequency. This relationship indicates that the period of a wave is the reciprocal of its frequency. Frequency refers to the number of complete cycles of a wave occurring in a unit of time, while the period is the time taken for one complete cycle of the wave to occur. As frequency and period are inversely related, the correct formula to express this relationship is Period = 1/Frequency. Choice A is incorrect as frequency and period are related. Choice B is incorrect as frequency and period are not equal. Choice C is incorrect as it suggests that frequency is directly proportional to period, which is not the case.

4. What is the product of the complete combustion of propane (C3H8)?

• A. CO2
• B. CO
• C. CH4
• D. C

Correct answer: A

Rationale: The complete combustion of propane (C3H8) results in the production of carbon dioxide (CO2) and water. When a hydrocarbon such as propane undergoes complete combustion, the carbon atoms combine with oxygen to form CO2. This makes choice A, CO2, the correct answer. Choices B, C, and D are incorrect as CO is carbon monoxide, CH4 is methane, and C is elemental carbon, none of which are the primary product of the complete combustion of propane.

5. Differentiate between genotype and phenotype in the context of gene expression.

• A. Genotype refers to the physical manifestation of a trait, while phenotype represents its underlying genetic makeup.
• B. Genotype encompasses the spectrum of possible traits encoded by an organism's genes, while phenotype signifies the specific trait observed.
• C. Genotype denotes the presence of dominant alleles, while phenotype reflects the influence of recessive alleles.
• D. There is no distinction; both terms are interchangeable.

Correct answer: B

Rationale: - Genotype refers to the genetic makeup of an organism, including all the genes and alleles it possesses. - Phenotype, on the other hand, refers to the observable physical characteristics or traits of an organism, which result from the interaction between its genotype and the environment. - While genotype represents the genetic potential or range of traits that an organism can express, phenotype reflects the actual expression of specific traits. - Therefore, option B correctly captures the distinction between genotype and phenotype in the context of gene expression.

Similar Questions