which of the following is the term used to represent alternative versions of a gene

HESI RN

Biology Practice Test

1. Which of the following 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 versions of a gene that can exist at a specific locus on a chromosome. This term specifically refers to the different forms of a gene that can exist. Choices B, C, and D are incorrect because they do not represent alternative versions of a gene. Binary fission is a form of asexual reproduction in single-celled organisms, while heterozygous and homozygous refer to the genetic makeup of an individual rather than alternative versions of a gene.

2. What is located on the rough endoplasmic reticulum?

A. Microvilli
B. Mitochondria
C. Lysosomes
D. Ribosomes

Correct answer: D

Rationale: The rough endoplasmic reticulum is studded with ribosomes, which are responsible for protein synthesis. Ribosomes are the correct answer because they are the organelles directly associated with the rough endoplasmic reticulum. Microvilli (choice A), mitochondria (choice B), and lysosomes (choice C) are not typically located on the rough endoplasmic reticulum. Microvilli are found on the surface of cells to increase surface area, mitochondria are the powerhouses of the cell responsible for energy production, and lysosomes are membrane-bound organelles containing digestive enzymes.

3. What is the main objective of the translation stage of protein synthesis?

A. To produce amino acids
B. To produce nucleotides
C. To produce fatty acids
D. To produce proteins

Correct answer: D

Rationale: The main objective of the translation stage of protein synthesis is to produce proteins. During translation, ribosomes decode mRNA sequences to synthesize proteins by linking amino acids together. Choice A, 'To produce amino acids,' is incorrect as amino acids are the building blocks of proteins and are not produced during translation. Choices B and C, 'To produce nucleotides' and 'To produce fatty acids,' are also incorrect as these molecules are not the direct products of the translation stage of protein synthesis.

4. What is the difference between saturated and unsaturated fatty acids?

A. There is no difference between saturated and unsaturated fatty acids.
B. Saturated fatty acids contain double bonds, unlike unsaturated fatty acids.
C. Saturated fatty acids often contain two or more pairs of double bonds, unlike unsaturated fatty acids.
D. Saturated fatty acids contain no double bonds, unlike unsaturated fatty acids.

Correct answer: D

Rationale: The correct answer is D. Saturated fatty acids contain no double bonds between the carbon atoms in their hydrocarbon chains, making them more solid at room temperature. Choice A is incorrect because there is a significant difference between saturated and unsaturated fatty acids. Choice B is incorrect as it inaccurately states that saturated fatty acids contain double bonds, which is a property of unsaturated fatty acids. Choice C is also incorrect as saturated fatty acids do not contain double bonds, let alone two or more pairs of double bonds.

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.