which 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

HESI RN

Biology Test

1. Which 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: The correct answer is B: Chromatin. Chromatin is responsible for packaging DNA into a more compact, dense shape to fit into the nucleus of a cell. This compact packaging helps protect the DNA structure and regulate gene expression. The Golgi apparatus is involved in modifying, sorting, and packaging proteins. The smooth endoplasmic reticulum is involved in lipid metabolism and detoxification. Mitochondria are known as the powerhouse of the cell, producing energy in the form of ATP.

2. What is the primary method of asexual reproduction used by most bacteria?

A. Meiosis
B. Mitosis
C. Binary fission
D. Interphase

Correct answer: C

Rationale: The correct answer is C: Binary fission. This is the main process through which most bacteria reproduce asexually. During binary fission, a single cell divides into two identical cells, each containing a copy of the genetic material. Choices A and B, meiosis and mitosis, are processes involved in sexual reproduction and are not used by bacteria for asexual reproduction. Choice D, interphase, is a stage of the cell cycle where the cell prepares for division and is not a method of reproduction.

3. What are the two primary products of photosynthesis?

A. Sugar and oxygen
B. Sugar and carbon dioxide
C. Oxygen and nitrogen
D. Nitrogen and carbon dioxide

Correct answer: A

Rationale: The correct answer is A: Sugar and oxygen. During photosynthesis, plants convert carbon dioxide and water into glucose (sugar) and oxygen using sunlight. Choice B, 'Sugar and carbon dioxide,' is incorrect because carbon dioxide is one of the reactants, not a product. Choice C, 'Oxygen and nitrogen,' is incorrect as nitrogen is not a direct product of photosynthesis. Choice D, 'Nitrogen and carbon dioxide,' is incorrect because nitrogen is not a product of photosynthesis, and carbon dioxide is a reactant.

4. During which stage of mitosis does the nuclear envelope begin to disappear and the chromosomes start attaching to the spindle forming along the cell's axis?

A. Prometaphase
B. Metaphase
C. Anaphase
D. Prophase

Correct answer: A

Rationale: The correct answer is A, Prometaphase. During prometaphase, the nuclear envelope disintegrates, and chromosomes start attaching to spindle fibers. In metaphase, chromosomes align in the middle of the cell. Anaphase is characterized by the separation of sister chromatids, and prophase involves the condensation of chromosomes and the beginning of spindle formation.

5. 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.