Nursing Elites

1. Which of the following is NOT a source of genetic variation in a population?

• A. Mutations in genes
• B. Genetic drift (random fluctuations in allele frequencies)
• C. Gene flow (movement of genes between populations)
• D. Blending inheritance (traits of parents are averaged in offspring)

Correct answer: D

Rationale: Rationale: A) Mutations in genes: Mutations are changes in the DNA sequence that can introduce new alleles into a population, leading to genetic variation. B) Genetic drift (random fluctuations in allele frequencies): Genetic drift refers to random changes in allele frequencies in a population, which can lead to genetic variation through chance events. C) Gene flow (movement of genes between populations): Gene flow occurs when individuals move between populations, bringing new alleles with them and increasing genetic variation within populations. D) Blending inheritance (traits of parents are averaged in offspring): Blending inheritance was a historical theory that suggested offspring inherit a blend of traits from their parents, leading to a reduction in genetic variation over time. However, this concept has been disproven by the understanding of Mendelian genetics, where traits are inherited independently and do not blend together. Therefore, blending inheritance does not contribute

2. Which of the following conditions is characterized by a wasting or decrease in muscle mass?

• A. Hypertrophy
• B. Atrophy
• C. Spasticity
• D. Myopathy

Correct answer: B

Rationale: Atrophy is the correct answer as it is characterized by a wasting or decrease in muscle mass. Hypertrophy, on the other hand, refers to an increase in muscle size. Spasticity is associated with increased muscle tone due to continuous contraction of muscles. Myopathy, on the other hand, is a broad term used to describe various muscle diseases affecting muscle tissue, which may or may not involve muscle wasting.

3. Which of these organs is NOT involved in the production of digestive enzymes?

• A. Mouth
• B. Stomach
• C. Pancreas
• D. Small intestine

Correct answer: A

Rationale: A) Mouth: The mouth is involved in the mechanical breakdown of food through chewing and the initiation of carbohydrate digestion by the enzyme amylase in saliva, but it does not produce digestive enzymes. The salivary amylase in the mouth helps in breaking down carbohydrates. However, it is not an organ that produces digestive enzymes. B) Stomach: The stomach produces gastric juices containing enzymes like pepsin that help break down proteins. C) Pancreas: The pancreas produces various digestive enzymes such as amylase, lipase, and proteases that aid in the digestion of carbohydrates, fats, and proteins. D) Small intestine: The small intestine produces enzymes such as peptidases, sucrase, lactase, and maltase that further break down proteins, carbohydrates, and fats for absorption. Therefore, the mouth is the organ that is NOT involved in the production of digestive enzymes.

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 function do ribosomes serve within the cell?

• A. Ribosomes are responsible for cell movement.
• B. Ribosomes aid in protein synthesis.
• C. Ribosomes help protect the cell from its environment.
• D. Ribosomes have enzymes that help with digestion.

Correct answer: B

Rationale: Ribosomes serve a crucial role in protein synthesis by translating mRNA into proteins. They are not involved in cell movement, protecting the cell from the environment, or aiding in digestion. Choice A is incorrect because ribosomes are not responsible for cell movement. Choice C is incorrect because ribosomes do not primarily protect the cell from its environment. Choice D is incorrect because ribosomes do not have enzymes that aid in digestion.

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