which of the following is often referred to as the powerhouse of the cell

HESI RN

Biology Practice Test

1. 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.

2. The liver is an organ responsible for detoxifying the body of many harmful substances. You might expect the liver to contain a high amount of which of the following?

A. Rough endoplasmic reticulum
B. Smooth endoplasmic reticulum
C. Mitochondria
D. Lysosomes

Correct answer: B

Rationale: The correct answer is B: Smooth endoplasmic reticulum. The liver contains a high amount of smooth endoplasmic reticulum because it plays a significant role in detoxification processes, such as the synthesis of detoxifying enzymes and lipids. Choice A (Rough endoplasmic reticulum) is incorrect because the rough endoplasmic reticulum is more involved in protein synthesis and processing. Choice C (Mitochondria) is incorrect as mitochondria are primarily responsible for energy production. Choice D (Lysosomes) is incorrect because lysosomes are organelles involved in intracellular digestion and waste removal, not specifically related to detoxification.

3. 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.

4. Which of the following organelles is known as the cell's transportation center?

A. Golgi apparatus
B. Endoplasmic reticulum
C. Mitochondria
D. Lysosomes

Correct answer: B

Rationale: The correct answer is B, Endoplasmic reticulum. The endoplasmic reticulum is involved in the synthesis and transport of proteins and lipids within the cell. The Golgi apparatus is responsible for modifying, sorting, and packaging proteins and lipids for transport. Mitochondria are known as the powerhouse of the cell, producing energy in the form of ATP. Lysosomes are involved in the digestion and recycling of cellular waste.

5. 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.