the smallest and most basic unit of matter is the

HESI RN

Biology Test

1. What is the smallest and most basic unit of matter?

A. Micromolecule
B. Atom
C. Organelle
D. Molecule

Correct answer: B

Rationale: The correct answer is B, Atom. An atom is the smallest unit of matter that retains the properties of an element. Choice A, Micromolecule, is incorrect because molecules are composed of atoms bonded together, making them larger than individual atoms. Choice C, Organelle, is incorrect as organelles are structures within cells, not the basic unit of matter. Choice D, Molecule, is incorrect as molecules are made up of atoms bonded together, so they are not the smallest unit of matter.

2. Asexual reproduction is a type of reproduction by which offspring arise from:

A. Two identical cells
B. A single cell
C. Two cells
D. Four daughter cells

Correct answer: B

Rationale: Asexual reproduction is a type of reproduction where a single parent cell divides to produce genetically identical offspring. The correct answer is 'B: A single cell' because asexual reproduction does not involve the fusion of two cells. Choice A ('Two identical cells') is incorrect because asexual reproduction does not involve two cells. Choice C ('Two cells') is incorrect because asexual reproduction typically involves only one parent cell. Choice D ('Four daughter cells') is incorrect because asexual reproduction does not necessarily involve the production of four daughter cells.

3. Which of the following is not true of mitosis?

A. Mitosis produces daughter cells
B. Mitosis has five main stages
C. Mitosis can only be done by haploids
D. Following mitosis, daughter cells are identical to parent cells

Correct answer: C

Rationale: The correct answer is C. Mitosis occurs in diploid cells and involves stages that result in the production of two identical daughter cells. Haploids do not undergo mitosis, as mitosis is a process specific to diploid cells. Choice A is true as mitosis does produce daughter cells. Choice B is incorrect as mitosis typically consists of four main stages: prophase, metaphase, anaphase, and telophase. Choice D is true, as one of the main outcomes of mitosis is the production of daughter cells that are genetically identical to the parent cell.

4. 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.

5. Which of the following statements is true if a molecule exhibits adhesion?

A. Two molecules of the same substance have the ability to stay bonded to one another
B. The molecule has the ability to bond to or attract other molecules
C. A molecule has the ability to increase its heat when necessary
D. The molecule has the ability to form hydrogen bonds

Correct answer: B

Rationale: The correct statement is that if a molecule exhibits adhesion, it has the ability to bond to or attract other molecules. Adhesion refers to the ability of a molecule to bind to or attract different types of molecules. Choice A is incorrect because adhesion is about bonding to different molecules, not the same substance. Choice C is incorrect as adhesion does not relate to the ability of a molecule to increase its heat. Choice D is incorrect because forming hydrogen bonds is a specific type of interaction and not a general characteristic of molecules exhibiting adhesion.