what cell structure is responsible for efficiently packaging dna into a small volume to fit into the nucleus of a cell and protect the dna structure a

HESI RN

Biology Test

1. What cell structure is responsible for efficiently packaging DNA into a small volume to fit into the nucleus of a cell and protect the DNA structure and sequence?

A. Golgi apparatus
B. Chromatin
C. Smooth endoplasmic reticulum
D. Mitochondria

Correct answer: B

Rationale: Chromatin is the correct answer. Chromatin is responsible for packaging DNA into a more compact, dense structure to fit into the nucleus and protect the DNA. The Golgi apparatus is involved in processing and packaging proteins, not DNA. Smooth endoplasmic reticulum is involved in lipid metabolism and detoxification. Mitochondria are known as the powerhouse of the cell responsible for energy production, not DNA packaging.

2. In meiosis, the chromosome number is reduced from:

A. 46 to 23
B. 46 to 33
C. 28 to 14
D. 24 to 12

Correct answer: A

Rationale: The correct answer is A: "46 to 23." In meiosis, the chromosome number is reduced by half to form gametes for sexual reproduction. In humans, where the diploid chromosome number is 46, meiosis results in haploid cells with 23 chromosomes. Choices B, C, and D are incorrect because they do not represent the correct reduction in chromosome number during meiosis.

3. Which two items react during cellular respiration?

A. Glucose and water
B. Carbon dioxide and water
C. Carbon dioxide and oxygen
D. Glucose and oxygen

Correct answer: D

Rationale: The correct answer is D: Glucose and oxygen. During cellular respiration, glucose and oxygen react in the presence of enzymes to produce carbon dioxide, water, and energy in the form of ATP. Choice A (Glucose and water) is incorrect because water is a product of cellular respiration, not a reactant. Choice B (Carbon dioxide and water) is incorrect as carbon dioxide is produced during cellular respiration, not a reactant. Choice C (Carbon dioxide and oxygen) is incorrect because oxygen is a reactant in cellular respiration, not a product.

4. Which of the following is not found in a prokaryotic cell?

A. Plasma membrane
B. Cytoplasm
C. Nucleus
D. Ribosomes

Correct answer: C

Rationale: The correct answer is C, 'Nucleus.' Prokaryotic cells do not have a defined nucleus, unlike eukaryotic cells. The plasma membrane, cytoplasm, and ribosomes are all components found in prokaryotic cells. The plasma membrane surrounds the cell and regulates what enters and exits, the cytoplasm is the gel-like substance that fills the cell, and ribosomes are responsible for protein synthesis.

5. Which of the following molecules contains the code required for replication?

A. Deoxyribonucleic acid (DNA)
B. Transfer RNA (tRNA)
C. Messenger RNA (mRNA)
D. Ribonucleic acid (RNA)

Correct answer: A

Rationale: The correct answer is A: Deoxyribonucleic acid (DNA). DNA contains the genetic information essential for replication, ensuring the accurate transmission of genetic material from one generation to the next. Choice B, Transfer RNA (tRNA), is involved in protein synthesis, not replication. Choice C, Messenger RNA (mRNA), carries genetic information from DNA to the ribosome but does not contain the code for replication. Choice D, Ribonucleic acid (RNA), is a broader category that includes both mRNA and tRNA, but the specific molecule containing the code required for replication is DNA.