which of the following serves as the information processing and administrative center of the cell

HESI RN

Biology Practice Test

1. 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.

2. At the beginning of meiosis, how many chromosomes does the diploid parent cell have?

A. 23
B. 24
C. 46
D. 54

Correct answer: C

Rationale: The correct answer is C: 46. At the start of meiosis, the diploid parent cell contains 46 chromosomes. During meiosis, the number of chromosomes is halved, resulting in each gamete having 23 chromosomes. Choice A (23) is incorrect because that is the number of chromosomes in a human gamete, not the parent cell. Choice B (24) and Choice D (54) are also incorrect as they do not reflect the correct number of chromosomes in a diploid parent cell at the beginning of meiosis.

3. What function does cholesterol, a phospholipid, serve within the cell membrane?

A. It builds up fats to make the structure more flexible
B. It allows protein channels to form
C. It makes the structure very rigid and impermeable
D. It stabilizes the membrane structure

Correct answer: D

Rationale: Cholesterol helps to maintain the fluidity and stability of the cell membrane by fitting between the phospholipid molecules. Choice A is incorrect because cholesterol does not build up fats in the cell membrane. Choice B is incorrect as protein channels are formed by proteins, not cholesterol. Choice C is incorrect as cholesterol actually helps regulate the fluidity of the membrane, making it less rigid and more permeable.

4. What is located on the rough endoplasmic reticulum?

A. Microvilli
B. Mitochondria
C. Lysosomes
D. Ribosomes

Correct answer: D

Rationale: The rough endoplasmic reticulum is studded with ribosomes, not microvilli, mitochondria, or lysosomes. Ribosomes are responsible for protein synthesis, making them an essential component of the rough endoplasmic reticulum.

5. The term pleiotropy is best defined as which of the following?

A. A situation in which one gene remains unexpressed
B. One gene influencing multiple, seemingly unrelated phenotypic traits
C. Two genes affected by a single allele
D. A condition in which multiple genes are missing

Correct answer: B

Rationale: Pleiotropy is best defined as one gene influencing multiple, seemingly unrelated phenotypic traits. This phenomenon showcases the multifunctionality of genes, where a single gene can have effects on various aspects of an organism's phenotype. Choices A, C, and D do not accurately capture the concept of pleiotropy. Option A refers to gene expression, not pleiotropy. Option C describes genetic interactions but not in the context of pleiotropy. Option D talks about missing genes, which is unrelated to the definition of pleiotropy.