which of the following is not found in a prokaryotic cell

HESI RN

Biology Test

1. 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.

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 of the following molecules acts as the genetic code's messenger?

A. RNA
B. Proteins
C. DNA
D. Carbohydrates

Correct answer: A

Rationale: The correct answer is RNA. RNA, particularly mRNA, serves as the messenger that carries genetic information from DNA to the ribosome, where proteins are synthesized. Proteins (choice B) are not the genetic code's messenger; they are synthesized based on the information carried by RNA. DNA (choice C) stores the genetic information but does not directly act as the messenger. Carbohydrates (choice D) are not involved in transmitting genetic information.

4. What is the difference between saturated and unsaturated fatty acids?

A. There is no difference between saturated and unsaturated fatty acids.
B. Saturated fatty acids contain double bonds, unlike unsaturated fatty acids.
C. Saturated fatty acids often contain two or more pairs of double bonds, unlike unsaturated fatty acids.
D. Saturated fatty acids contain no double bonds, unlike unsaturated fatty acids.

Correct answer: D

Rationale: The correct answer is D. Saturated fatty acids contain no double bonds between the carbon atoms in their hydrocarbon chains, making them more solid at room temperature. Choice A is incorrect because there is a significant difference between saturated and unsaturated fatty acids. Choice B is incorrect as it inaccurately states that saturated fatty acids contain double bonds, which is a property of unsaturated fatty acids. Choice C is also incorrect as saturated fatty acids do not contain double bonds, let alone two or more pairs of double bonds.

5. Which of the following serves as the information processing and administrative center of the cell?

A. Golgi apparatus
B. Cytoplasm
C. Nucleus
D. Lysosomes

Correct answer: C

Rationale: The correct answer is C, the nucleus. The nucleus is indeed the information processing and administrative center of the cell as it contains the genetic material (DNA) and is responsible for controlling cellular activities. The Golgi apparatus (Choice A) is involved in processing and packaging proteins, the cytoplasm (Choice B) is the fluid that fills the cell and provides a medium for organelles to be suspended, and lysosomes (Choice D) are responsible for digesting waste materials and foreign invaders. Therefore, the nucleus is the most appropriate choice for the given function.