Nursing Elites

1. What is the difference between a homozygous recessive genotype and a homozygous dominant genotype?

• A. Both have the same phenotype, but different genotypes.
• B. Both have the same genotype, but different phenotypes.
• C. Homozygous recessive has two dominant alleles, while homozygous dominant has two recessive alleles.
• D. Homozygous recessive has two identical recessive alleles, while homozygous dominant has two identical dominant alleles.

Correct answer: D

Rationale: - Homozygous recessive genotype refers to an individual having two identical recessive alleles for a particular gene (e.g., rr for a trait where r represents the recessive allele). - Homozygous dominant genotype refers to an individual having two identical dominant alleles for a particular gene (e.g., RR for a trait where R represents the dominant allele). - The difference between the two genotypes lies in the specific alleles present in each case, with homozygous recessive having two recessive alleles and homozygous dominant having two dominant alleles. - This genetic difference results in different phenotypes being expressed, as the dominant allele typically masks the expression of the recessive allele in heterozygous individuals.

2. What are the phases of bacterial growth and infection?

• A. Lag, exponential, stationary, death
• B. Exponential, stationary, lag, death
• C. Stationary, exponential, lag, death
• D. Lag, stationary, exponential, death

Correct answer: A

Rationale: The correct answer is A: Lag, exponential, stationary, death. The phases of bacterial growth start with the lag phase where bacteria acclimate to their environment, followed by the exponential phase characterized by rapid growth. This is then followed by the stationary phase where growth slows as resources deplete, and finally, the death phase where the population declines. Choice B is incorrect as it has the order of phases mixed up. Choice C is incorrect as it also has the order of phases mixed up. Choice D is incorrect as it has the stationary phase occurring before the exponential phase, which is inaccurate.

3. When animals eat, insulin is released from the pancreas, stimulating glucose uptake by the liver. When glucose levels drop, the pancreas reduces insulin release. This is an example of which mechanism for maintaining homeostasis?

• A. Negative feedback.
• B. Positive feedback.
• C. Stress response.
• D. Parasympathetic regulation.

Correct answer: A

Rationale: This mechanism is an example of negative feedback. Negative feedback systems work to counteract changes in the body and maintain a stable internal environment (homeostasis). In this case, the release of insulin in response to high glucose levels is followed by a reduction in insulin release when glucose levels drop. This response helps regulate glucose levels and return them to a normal range, demonstrating the characteristic of negative feedback where the body's response opposes the initial stimulus to maintain equilibrium. Positive feedback would amplify the initial change rather than counteract it, so it is not the correct choice. Stress response and parasympathetic regulation are not directly involved in this glucose regulation process, making them incorrect choices.

4. Which gas is the most abundant in Earth's atmosphere?

• A. Nitrogen
• B. Oxygen
• C. Carbon dioxide
• D. Argon

Correct answer: A

Rationale: Nitrogen is the most abundant gas in Earth's atmosphere, constituting approximately 78% of the air we breathe. It is essential for various biological processes, including plant growth and nitrogen fixation. Moreover, nitrogen is a key component of the greenhouse effect, playing a crucial role in regulating the planet's temperature. Oxygen, while important for respiration, comprises about 21% of the atmosphere. Carbon dioxide, though vital for photosynthesis and a greenhouse gas, is present in much lower concentrations than nitrogen. Argon, an inert gas, is a minor component of the atmosphere.

5. Which property of a substance remains constant regardless of changes in its shape or size?

• A. Mass
• B. Weight
• C. Volume
• D. Density

Correct answer: A

Rationale: The correct answer is 'Mass.' Mass is a measure of the amount of matter in an object and remains constant regardless of changes in its shape or size. Weight, volume, and density can all change depending on the conditions, but mass remains the same. Weight is the force exerted on an object due to gravity, which can change based on the gravitational pull. Volume is the amount of space an object occupies, which can change if the shape or size of the object changes. Density is the mass of a substance per unit volume, which can change if either the mass or volume changes. Therefore, in this scenario, mass is the property that remains constant regardless of changes in shape or size.

Similar Questions