Nursing Elites

1. What generates action potentials, the all-or-nothing electrical signals traveling along neurons?

• A. Glucose
• B. Sodium and potassium ions
• C. Neurotransmitters
• D. Myelin

Correct answer: B

Rationale: Action potentials, the all-or-nothing electrical signals traveling along neurons, are generated by the movement of sodium and potassium ions across the neuronal membrane. This movement creates changes in the membrane potential, leading to the propagation of the electrical signal along the neuron. Glucose is a source of energy for neurons but is not directly involved in generating action potentials. Neurotransmitters are involved in communication between neurons but do not directly generate action potentials. Myelin is a fatty substance that insulates and speeds up the conduction of action potentials but does not generate them.

2. 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.

3. What is the name for the hard, protective protein that makes up hair and nails?

• A. Collagen
• B. Keratin
• C. Elastin
• D. Fibrin

Correct answer: B

Rationale: Keratin is the correct answer as it is the hard, protective protein that comprises hair and nails. Collagen is a different type of protein found in connective tissues, providing structure and support. Elastin imparts elasticity to tissues, allowing them to stretch and recoil. Fibrin is a protein involved in the blood clotting process and is not related to the structure of hair and nails. Therefore, choices A, C, and D are incorrect in the context of the question.

4. What potential consequences can chromosomal nondisjunction have on offspring?

• A. Down syndrome, caused by an extra copy of chromosome 21.
• B. Turner syndrome, characterized by the absence of one X chromosome in females.
• C. Klinefelter syndrome, featuring one or more extra X chromosomes in males.
• D. All of the above.

Correct answer: D

Rationale: - Chromosomal nondisjunction is the failure of homologous chromosomes or sister chromatids to separate properly during cell division, leading to an abnormal number of chromosomes in the resulting cells. - Down syndrome is caused by an extra copy of chromosome 21, resulting from nondisjunction during meiosis. Individuals with Down syndrome have three copies of chromosome 21 instead of the usual two. - Turner syndrome is characterized by the absence of one X chromosome in females, leading to a variety of physical and developmental features. - Klinefelter syndrome features one or more extra X chromosomes in males, typically resulting in infertility and other physical characteristics. Therefore, chromosomal nondisjunction can lead to various genetic disorders such as Down syndrome, Turner syndrome, and Klinefelter syndrome, making option D the correct answer.

5. What protein complex controls the progression of mitosis through its activation and degradation?

• A. Ribosome
• B. Cyclin-dependent kinase (CDK)
• C. Centriole
• D. Microtubule

Correct answer: B

Rationale: A) Ribosome: Ribosomes are cellular organelles responsible for protein synthesis and are not directly involved in controlling the progression of mitosis. B) Cyclin-dependent kinase (CDK): CDKs are a family of protein kinases that regulate the cell cycle, including the progression of mitosis. CDK activity is controlled by cyclins, which bind to CDKs to activate them at specific points in the cell cycle. The activation and degradation of cyclins regulate the activity of CDKs, which in turn control the progression of mitosis. C) Centriole: Centrioles are involved in organizing the microtubules of the mitotic spindle but do not directly control the progression of mitosis. D) Microtubule: Microtubules are structural components of the cytoskeleton and are involved in various cellular processes, including mitosis, but they do not control

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