how do rna and dna derive their names

HESI A2

HESI A2 Biology 2024

1. From which component do RNA and DNA derive their names?

A. From the sugar each contains
B. From the structure of their nucleotides
C. From the information they transfer
D. From their formative processes

Correct answer: A

Rationale: RNA and DNA derive their names from the sugar each contains. RNA stands for Ribonucleic Acid, with 'ribo' indicating the ribose sugar in its structure. DNA stands for Deoxyribonucleic Acid, with 'deoxyribo' referring to the deoxyribose sugar in its structure. The sugars in RNA and DNA molecules distinguish them and are the basis for their names. Choices B, C, and D are incorrect as they do not accurately explain how RNA and DNA derive their names.

2. A cell containing 12 chromosomes divides into daughter cells in mitosis. How many chromosomes are in each daughter cell?

A. 3
B. 6
C. 12
D. 24

Correct answer: C

Rationale: During mitosis, the cell undergoes nuclear division without changing the number of chromosomes. Therefore, the daughter cells produced will have the same number of chromosomes as the parent cell. In this case, since the parent cell contains 12 chromosomes, each daughter cell will also have 12 chromosomes. Choices A, B, and D are incorrect because during mitosis, the chromosome number remains the same, and daughter cells inherit the same number of chromosomes as the parent cell.

3. What type of tissue is fat?

A. Connective
B. Muscle
C. Nervous
D. Epithelial

Correct answer: A

Rationale: Fat is a type of loose connective tissue known as adipose tissue. Adipose tissue primarily functions to store energy and provide cushioning and insulation for organs. While muscle tissue is responsible for movement, nervous tissue transmits nerve impulses, and epithelial tissue covers and protects body surfaces, fat specifically falls under the category of connective tissue.

4. What is the composition of the plasma membrane?

A. Proteins
B. Lipids
C. Carbohydrates
D. Nucleotides

Correct answer: B

Rationale: The plasma membrane is composed of lipids, proteins, and carbohydrates. While proteins are an essential component of the plasma membrane, it is not the only constituent. Carbohydrates and lipids also play crucial roles in the structure and function of the plasma membrane. Nucleotides are not part of the primary structural components of the plasma membrane, making this choice incorrect.

5. Why do high-salt content foods not require refrigeration to prevent spoilage?

A. Osmosis
B. Diffusion
C. Active transport
D. Passive transport

Correct answer: A

Rationale: Osmosis is the natural process that prevents high-salt content foods from spoiling without the need for refrigeration. Osmosis involves the movement of water across a semi-permeable membrane from an area of lower solute concentration (water) to an area of higher solute concentration (salt). In high-salt content foods, the salt acts as a preservative by drawing moisture out of bacteria or other microorganisms, making it difficult for them to survive and spoil the food. This process helps in preserving the food and preventing spoilage even without refrigeration. Choices B, C, and D are incorrect because they do not involve the specific mechanism of water movement in response to the salt concentration in high-salt content foods.