dna and rna are both subunits of which biological molecule

HESI RN

Biology Practice Test

1. DNA and RNA are both subunits of which biological molecule?

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

Correct answer: A

Rationale: The correct answer is A: Nucleic acids. DNA and RNA are both types of nucleic acids, which are fundamental biological molecules responsible for storing and transmitting genetic information. Choice B, Proteins, are not subunits of DNA and RNA but are composed of amino acids. Carbohydrates, choice C, are another type of biological molecule involved in energy storage and structural support, not subunits of DNA and RNA. Lipids, choice D, are a diverse group of molecules that include fats, oils, and steroids, but they are not subunits of DNA and RNA.

2. Which of the following is often referred to as the powerhouse of the cell?

A. Nucleus
B. Chromatin
C. Mitochondria
D. Ribosomes

Correct answer: C

Rationale: Mitochondria are known as the powerhouse of the cell because they generate most of the cell's supply of ATP, which is the energy currency used for various cellular processes. The nucleus (Choice A) is the control center of the cell, housing genetic material. Chromatin (Choice B) is a complex of DNA and proteins within the nucleus. Ribosomes (Choice D) are responsible for protein synthesis and not the primary energy production in the cell.

3. What is the science of biological classification commonly called?

A. Taxonomy
B. Physiology
C. Botany
D. Zoology

Correct answer: A

Rationale: Taxonomy is the science of naming, defining, and classifying groups of biological organisms based on shared characteristics. Physiology (choice B) is the study of the functions and processes of living organisms, not classification. Botany (choice C) is the study of plants, while Zoology (choice D) is the study of animals. Therefore, the correct answer is Taxonomy (choice A).

4. 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, not microvilli, mitochondria, or lysosomes. Ribosomes are responsible for protein synthesis, making them an essential component of the rough endoplasmic reticulum.

5. Which organelle has the ability to hydrolyze fats, nucleic acids, proteins, and sugars?

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

Correct answer: C

Rationale: The correct answer is C, Lysosomes. Lysosomes contain hydrolytic enzymes that are capable of breaking down various biomolecules such as fats, nucleic acids, proteins, and sugars. This organelle acts as the 'digestive system' of the cell. Choices A, B, and D are incorrect because chloroplasts are involved in photosynthesis, mitochondria are responsible for energy production, and ribosomes are responsible for protein synthesis, not the hydrolysis of biomolecules.