Nursing Elites

1. How many pairs of homologous chromosomes do humans have?

• A. 13
• B. 23
• C. 26
• D. 46

Correct answer: D

Rationale: The correct answer is D: 46. Humans have 23 pairs of chromosomes, which include 22 pairs of autosomes and 1 pair of sex chromosomes. Homologous chromosomes are pairs of chromosomes that contain the same genes, one from each parent. Therefore, humans have a total of 46 chromosomes, with 23 pairs of homologous chromosomes. Choices A, B, and C are incorrect as they do not represent the total number of chromosomes in humans or the number of pairs of homologous chromosomes.

2. How should a researcher test the hypothesis that eating chocolate leads to acne in teenagers?

• A. Take 100 teenagers and feed each one a different amount of chocolate daily for 60 days; then test for acne.
• B. Take 100 teenagers and feed 50 two bars of chocolate daily for 60 days while the other 50 eat no chocolate; then test for acne.
• C. Take 1 teenager and feed him or her two bars of chocolate for 30 days and no chocolate for 30 days; then test for acne.
• D. Take 100 teenagers and feed them no chocolate for 30 days and two bars of chocolate apiece for 30 days; then test for acne.

Correct answer: B

Rationale: Option B is the correct approach to test the hypothesis that eating chocolate leads to acne in teenagers. This method involves having a control group (50 teenagers not consuming chocolate) and an experimental group (50 teenagers consuming two bars of chocolate daily), which allows for comparison. By having two distinct groups, researchers can assess the impact of chocolate consumption on acne development. Option A lacks a control group for comparison, making it harder to attribute any observed effects specifically to chocolate consumption. Option C only involves a single subject, which limits the generalizability of the results. Option D, where all teenagers experience both conditions, does not allow for a direct comparison between chocolate consumption and acne development, as all subjects are exposed to both conditions.

3. A student was asked to count birds in a given location over a 24-hour period. Which count would make their data most valid?

• A. Count birds at one feeder every 6 hours.
• B. Count birds at three feeders at noon and 6:00 P.M.
• C. Count birds at one feeder at noon and 6:00 P.M.
• D. Count birds at three feeders every 6 hours.

Correct answer: C

Rationale: Counting birds at one feeder at consistent time intervals (noon and 6:00 P.M.) over a 24-hour period ensures that the data collected are evenly distributed and provide a more accurate representation of the bird population in that location throughout the day. This method allows for observations during different times of the day, capturing potential variations in bird activity and distribution. Choice A is not as effective as it lacks observations at different times of the day, potentially missing variations in bird behavior. Choice B involves multiple locations and times, which could introduce more variables and make it harder to analyze the data accurately. Choice D, counting birds at three feeders every 6 hours, may provide too frequent data points and not cover all significant time intervals for observing bird activity.

4. What is the main function of the cell membrane?

• A. Energy production
• B. Communication
• C. Protein synthesis
• D. Waste removal

Correct answer: B

Rationale: The main function of the cell membrane is communication. It acts as a barrier that regulates the passage of substances in and out of the cell, maintaining cellular homeostasis. Choices A, C, and D are incorrect because energy production occurs in the mitochondria, protein synthesis takes place in the ribosomes, and waste removal is primarily handled by the lysosomes and other organelles within the cell.

5. Which of the following molecules is an important component of the plasma membrane?

• A. Phospholipids
• B. Steroids
• C. Sugars
• D. Amino acids

Correct answer: A

Rationale: Phospholipids are indeed a crucial component of the plasma membrane. They have a unique structure with hydrophilic heads and hydrophobic tails, which allows them to form the lipid bilayer of the membrane. Steroids, sugars, and amino acids are not primary components of the plasma membrane. Steroids are a different type of lipid, sugars are often found in glycoproteins on the membrane surface, and amino acids are the building blocks of proteins, some of which are membrane proteins, but not the membrane itself.

Similar Questions