the three main events of the haploid cell cycle are

HESI A2

Biology HESI A2 Practice Test

1. What are the three main events of the haploid cell cycle?

A. DNA replication, mitosis, and cytokinesis
B. DNA replication, meiosis, and cytokinesis
C. DNA replication, cytokinesis, and degradation
D. Mitosis, meiosis, and apoptosis

Correct answer: A

Rationale: In the haploid cell cycle, the three main events are DNA replication, where the cell's genetic material is duplicated; mitosis, which is the division of the nucleus to ensure each daughter cell receives a complete set of chromosomes; and cytokinesis, the division of the cell cytoplasm to separate the two daughter cells. Meiosis is not part of the haploid cell cycle as it occurs in diploid cells to produce haploid gametes. Apoptosis is a process of programmed cell death and is not a routine event in the cell cycle. Therefore, the correct answer is A. Choices B, C, and D are incorrect as meiosis and apoptosis are not part of the haploid cell cycle, and degradation is not a typical event in the cell cycle.

2. What is the fundamental unit of life?

A. Atom
B. Cell
C. Tissue
D. Organ

Correct answer: B

Rationale: The correct answer is 'B: Cell.' Cells are indeed the fundamental unit of life as they are responsible for all living functions, including growth, reproduction, and maintaining homeostasis. While atoms are the basic building blocks of matter, cells are the smallest structural and functional unit of living organisms. Choices C and D, tissue and organ respectively, are composed of multiple cells working together and are not considered the basic unit of life.

3. How many phases are there in the process of mitosis?

A. 2
B. 3
C. 4
D. 5

Correct answer: C

Rationale: The correct answer is C: '4'. Mitosis consists of four phases: prophase, metaphase, anaphase, and telophase. These phases are crucial in the orderly division of the cell's genetic material. Choice A is incorrect because mitosis is a more complex process involving multiple phases. Choice B is incorrect as it is one phase short of the total phases in mitosis. Choice D is incorrect as mitosis does not consist of five phases.

4. What is the main function of the cell membrane?

A. Energy production
B. Communication
C. Protein synthesis
D. Waste removal

Correct answer: B

Rationale: The main function of the cell membrane is communication. It acts as a barrier that regulates the passage of substances in and out of the cell, maintaining cellular homeostasis. Choices A, C, and D are incorrect because energy production occurs in the mitochondria, protein synthesis takes place in the ribosomes, and waste removal is primarily handled by the lysosomes and other organelles within the cell.

5. Phenotype refers to the _ of an individual.

A. Genetic makeup
B. Actual physical appearance
C. Recessive alleles
D. None of the above

Correct answer: B

Rationale: Phenotype refers to the actual physical appearance and characteristics of an individual, which are determined by the interaction of both genetic makeup (genotype) and environmental factors. It includes visible traits such as height, eye color, and hair type. Choice A, genetic makeup, refers to the genotype, which is the genetic constitution of an organism. Choice C, recessive alleles, is a specific type of gene variant and does not encompass the entire concept of phenotype. Choice D, none of the above, is incorrect as phenotype does refer to the actual physical appearance of an individual.