which stage of mitosis is occurring when the nuclear envelope begins to disappear and the chromosomes begin to attach to the spindle that is forming a

HESI RN

Biology Test

1. 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.

2. 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.

3. Protein synthesis begins with a process known as transcription. Where does this process occur?

A. In the cytoplasm
B. In the nuclear envelope
C. In the ribosome unit
D. In the nucleus

Correct answer: D

Rationale: The correct answer is D: In the nucleus. Transcription, the initial step of protein synthesis, takes place in the nucleus where DNA is transcribed into mRNA. This mRNA then leaves the nucleus and enters the cytoplasm where translation occurs on the ribosomes. Choices A, B, and C are incorrect because transcription specifically occurs in the nucleus, not in the cytoplasm, nuclear envelope, or ribosome unit.

4. During cellular respiration, glycolysis takes place in the cytosol and produces how many molecules of ATP, pyruvate, and NADH?

A. two, two, two
B. two, four, two
C. two, four, four
D. four, four, four

Correct answer: A

Rationale: Glycolysis, the first step of cellular respiration, takes place in the cytosol and produces two molecules each of ATP, pyruvate, and NADH. Therefore, the correct answer is A. Choice B is incorrect as glycolysis produces two ATP molecules, not four. Choice C is incorrect as it incorrectly states that glycolysis produces four molecules of pyruvate and NADH. Choice D is incorrect because glycolysis produces two molecules of ATP, not four.

5. What is the difference between DNA and RNA?

A. RNA has an extra Phosphate group
B. DNA has one less oxygen than RNA
C. RNA has one less oxygen than DNA
D. DNA has an extra sugar molecule

Correct answer: B

Rationale: The correct answer is B. DNA has one less oxygen atom in its sugar molecule (deoxyribose) compared to RNA, which has a ribose sugar. Choice A is incorrect because RNA does not have an extra phosphate group. Choice C is incorrect as RNA actually has one more oxygen atom than DNA. Choice D is incorrect as DNA and RNA have different sugar molecules, with DNA having deoxyribose and RNA having ribose.