Nursing Elites

1. Which of the following terms is used to represent two alleles that are the same type?

• A. Homosynchronous
• B. Hypersynchronous
• C. Heterozygous
• D. Homozygous

Correct answer: D

Rationale: The correct answer is D, 'Homozygous.' Homozygous refers to having two identical alleles for a particular gene. In this context, 'Homosynchronous' (choice A) is not a recognized genetic term. 'Hypersynchronous' (choice B) is not a term used in genetics. 'Heterozygous' (choice C) refers to having two different alleles for a particular gene, which is the opposite of homozygous.

2. What is the composition of the cellular membrane?

• A. A bilayer of phospholipid molecules
• B. A single layer of phospholipid molecules
• C. Proteins that act as transport highways
• D. Carbohydrates

Correct answer: A

Rationale: The cellular membrane is primarily composed of a phospholipid bilayer, which consists of two layers of phospholipid molecules. These molecules have a hydrophilic (water-attracting) head and hydrophobic (water-repelling) tail, creating a barrier that separates the internal cellular environment from the external surroundings. While proteins are embedded within this bilayer and act as transport channels, receptors, and structural support, carbohydrates are found on the outer surface of the membrane for cell recognition and signaling purposes. Therefore, the correct answer is a bilayer of phospholipid molecules.

3. Which of the following options is the term used to represent alternative versions of a gene?

• A. Alleles
• B. Binary fission
• C. Heterozygous
• D. Homozygous

Correct answer: A

Rationale: The correct answer is A: Alleles. Alleles are different forms of a gene that can exist at a specific locus on a chromosome. They represent variations in a gene's DNA sequence. Choices B, C, and D are incorrect. Binary fission is a form of asexual reproduction in single-celled organisms, while heterozygous and homozygous refer to different combinations of alleles in an individual, not the alternative versions of a gene.

4. What function does cholesterol, a phospholipid, serve within the cell membrane?

• A. It builds up fats to make the structure more flexible
• B. It allows protein channels to form
• C. It makes the structure very rigid and impermeable
• D. It stabilizes the membrane structure

Correct answer: D

Rationale: Cholesterol helps to maintain the fluidity and stability of the cell membrane by fitting between the phospholipid molecules. Choice A is incorrect because cholesterol does not build up fats in the cell membrane. Choice B is incorrect as protein channels are formed by proteins, not cholesterol. Choice C is incorrect as cholesterol actually helps regulate the fluidity of the membrane, making it less rigid and more permeable.

5. What is the most significant contributor to cellular function?

• A. Proteins
• B. Phospholipids
• C. Carbohydrates
• D. Fatty acids

Correct answer: A

Rationale: The correct answer is A: Proteins. Proteins are the most significant contributor to cellular function as they play crucial roles in almost all biological processes. They act as enzymes that catalyze reactions, are involved in cell signaling pathways, and provide structural support to cells. Phospholipids (Choice B), while important for cell membrane structure, do not have the same diverse functions as proteins in cellular processes. Carbohydrates (Choice C) primarily serve as an energy source and structural components but are not as versatile in cellular functions as proteins. Fatty acids (Choice D) are essential components of cell membranes and energy storage molecules but do not have the same broad range of functions as proteins in cellular processes.

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