Nursing Elites

1. The Hardy-Weinberg equilibrium describes a population that is:

• A. Undergoing rapid evolution due to strong directional selection.
• B. Not evolving and at genetic equilibrium with stable allele frequencies.
• C. Experiencing a founder effect leading to a reduction in genetic diversity.
• D. Dominated by a single homozygous genotype that eliminates all variation.

Correct answer: B

Rationale: Rationale: The Hardy-Weinberg equilibrium describes a theoretical population in which allele frequencies remain constant from generation to generation, indicating that the population is not evolving. This equilibrium occurs under specific conditions: no mutation, no gene flow, random mating, a large population size, and no natural selection. In this scenario, all genotypes are in proportion to the allele frequencies, and genetic diversity is maintained. Options A, C, and D do not accurately describe a population in Hardy-Weinberg equilibrium. Option A suggests rapid evolution due to strong directional selection, which would disrupt the equilibrium. Option C mentions a founder effect, which can reduce genetic diversity but is not a characteristic of a population in Hardy-Weinberg equilibrium. Option D describes a population dominated by a single homozygous genotype, which also does not align with the genetic diversity seen in a population at Hardy-Weinberg equilibrium.

2. In the context of the cardiac cycle, the P wave on an electrocardiogram (ECG) represents:

• A. Atrial depolarization
• B. Ventricular depolarization
• C. Atrial repolarization
• D. Ventricular repolarization

Correct answer: A

Rationale: The correct answer is A: "Atrial depolarization." The P wave on an ECG represents the depolarization of the atria, specifically the spread of electrical activity through the atria causing them to contract and push blood into the ventricles. This is the first wave observed on the ECG and signifies the beginning of the cardiac cycle. Ventricular depolarization is represented by the QRS complex, atrial repolarization is typically not visible on a standard ECG due to its timing with the QRS complex, and ventricular repolarization is represented by the T wave. Therefore, option A is the most appropriate choice in this context.

3. The framework of bones, cartilage, ligaments, and tendons that provides structure, support, and facilitates movement is the:

• A. Muscular system
• B. Skeletal system
• C. Nervous system
• D. Endocrine system

Correct answer: B

Rationale: The correct answer is B: Skeletal system. The skeletal system is composed of bones, cartilage, ligaments, and tendons that work together to provide structure, support, and facilitate movement in the body. The bones serve as the framework that supports and protects the body's organs, while cartilage cushions the joints. Ligaments connect bones to each other, and tendons connect muscles to bones, allowing for movement. The muscular system (choice A) consists of muscles that work with the skeletal system to produce movement. The nervous system (choice C) controls and coordinates bodily functions through the brain, spinal cord, and nerves. The endocrine system (choice D) regulates various bodily functions through the release of hormones. Therefore, the skeletal system is the correct answer as it specifically refers to the framework of bones, cartilage, ligaments, and tendons that support and enable movement in the body.

4. What type of molecule forms the cell membrane and controls what enters and exits the cell?

• A. Proteins
• B. Carbohydrates
• C. Lipids
• D. Nucleic acids

Correct answer: C

Rationale: The correct answer is C: Lipids. The cell membrane is primarily composed of a double layer of lipids called phospholipids. These phospholipids have a hydrophilic (water-attracting) head and two hydrophobic (water-repelling) tails, which arrange themselves to form a barrier that controls the passage of substances in and out of the cell. While proteins are also present in the cell membrane and play important roles in transport and cell signaling, lipids are the main structural component responsible for the selective permeability of the membrane. Carbohydrates are typically found on the outer surface of the membrane and are involved in cell recognition and communication. Nucleic acids are not a major component of the cell membrane; they are primarily responsible for storing and transmitting genetic information within the cell.

5. Inhalation

• A. Expiration
• B. Respiration
• C. Aspiration
• D. Aspiration

Correct answer: B

Rationale: The correct answer is B: 'Respiration.' Inhalation refers to the process of breathing in air, while respiration is the overall process of gas exchange in the body, including both inhalation and exhalation. Expiration refers specifically to the process of breathing out air. Aspiration, on the other hand, refers to the act of inhaling foreign objects into the lungs, which can be harmful. Therefore, 'Respiration' is the most appropriate term related to 'Inhalation' as it encompasses the entire process of breathing and gas exchange in the body.

6. What property of a substance remains constant regardless of changes in its shape or size?

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

Correct answer: a

Rationale: Mass remains constant regardless of changes in an object's shape or size.

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