Nursing Elites

1. What is a monohybrid cross, and what is the ratio of dominant to recessive gene manifestation?

• A. A cross involving two traits, 9:3:3:1
• B. A cross involving one trait, 3:1
• C. A cross involving two traits, 1:2:1
• D. A cross involving one trait, 1:1

Correct answer: B

Rationale: A monohybrid cross is a genetic cross involving one trait. The ratio of dominant to recessive gene manifestation in the offspring is typically 3:1 when both parents are heterozygous. This ratio is the genotypic ratio, not just the phenotype ratio, where the dominant allele is present in 3 out of 4 offspring, and the recessive allele is present in 1 out of 4 offspring. Choice A is incorrect because it describes a dihybrid cross ratio. Choice C is incorrect as it represents the genotypic ratio for a monohybrid cross involving incomplete dominance. Choice D is incorrect as it does not reflect the typical ratio for a monohybrid cross.

2. Which of the following best describes a chemical change?

• A. Melting ice to form water
• B. Dissolving sugar in water
• C. Burning wood to produce ash
• D. Crushing a can to reduce its size

Correct answer: C

Rationale: A chemical change involves a chemical reaction where new substances are formed. Burning wood to produce ash is an example of a chemical change because the wood undergoes a chemical reaction to form a new substance (ash). In this process, the chemical composition of wood changes to produce ash, which is a new substance. On the other hand, melting ice to form water, dissolving sugar in water, and crushing a can to reduce its size are examples of physical changes. In these instances, the substances may change their physical state or appearance but do not undergo a chemical reaction to form new substances. Therefore, choice C is the correct answer as it represents a chemical change, while choices A, B, and D represent physical changes.

3. 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.

4. What is the process of breaking down fatty acids into acetyl-CoA, a key molecule in cellular respiration, called?

• A. Beta-oxidation
• B. Lipolysis
• C. Carbohydrate catabolism
• D. Nucleic acid catabolism

Correct answer: A

Rationale: Beta-oxidation is the correct term for the process of breaking down fatty acids into acetyl-CoA molecules. This essential process takes place in the mitochondria and is a pivotal step in fatty acid metabolism for energy production. Lipolysis, however, refers to the breakdown of fats into fatty acids and glycerol but does not specifically involve the conversion of fatty acids into acetyl-CoA. Carbohydrate catabolism focuses on breaking down carbohydrates into glucose for energy production and is not directly linked to the conversion of fatty acids into acetyl-CoA. Nucleic acid catabolism involves the breakdown of nucleic acids into nucleotides and is not associated with the conversion of fatty acids into acetyl-CoA.

5. What occurs in each of the three phases of the uterine cycle?

• A. Proliferative: uterine lining thickens
• B. Secretory: ovulation occurs
• C. Menstrual: uterine lining sheds
• D. Proliferative: uterine lining thickens

Correct answer: D

Rationale: The correct answer is D. In the proliferative phase of the uterine cycle, the uterine lining thickens in preparation for a possible pregnancy. Ovulation occurs around day 14 of the cycle. The menstrual phase is when the uterine lining sheds if pregnancy has not occurred. Choice A is a duplicate of the correct answer. Choice B is incorrect as ovulation occurs during the mid-cycle, which is the ovulatory phase, not the secretory phase. Choice C is incorrect because the uterine lining sheds during the menstrual phase, not the secretory phase.

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