proteins are polymers of 20 molecules called

HESI RN

Biology Test

1. Proteins are polymers of 20 molecules called:

A. Amino acids
B. Phospholipids
C. Carbohydrates
D. Fatty acids

Correct answer: A

Rationale: Proteins are indeed polymers made up of amino acids. Amino acids are the building blocks of proteins, where each protein has a unique sequence of amino acids that determines its structure and function. Phospholipids, carbohydrates, and fatty acids are not molecules that make up proteins. Phospholipids are the main components of cell membranes, carbohydrates are sugars used for energy and structural purposes, and fatty acids are building blocks of lipids.

2. Which of the following options correctly lists the five stages of mitosis in order from beginning to end?

A. Prophase, Prometaphase, Telophase, Metaphase, Anaphase
B. Prophase, Prometaphase, Metaphase, Anaphase, Telophase
C. Metaphase, Anaphase, Prophase, Prometaphase, Telophase
D. Metaphase, Telophase, Anaphase, Prophase, Prometaphase

Correct answer: B

Rationale: The correct order of the stages of mitosis is Prophase, Prometaphase, Metaphase, Anaphase, and Telophase. Choice A is incorrect because it has Anaphase and Metaphase in the wrong order. Choice C is incorrect as it starts with Metaphase, which is not the first stage of mitosis. Choice D is incorrect as it also has the stages in the wrong order, and it starts with Metaphase, which is incorrect.

3. In the hierarchical organizational system, which of these is the most restrictive category?

A. Genus
B. Class
C. Kingdom
D. Species

Correct answer: D

Rationale: In the biological classification hierarchy, species is the most specific level, defining individual organisms that can interbreed. While genus, class, and kingdom are also categories in the hierarchy, they are broader and encompass a wider range of organisms compared to species. Genus groups together similar species, class groups similar orders, and kingdom is the broadest category grouping together similar phyla.

4. 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.

5. Water is a polar molecule that can be:

A. cohesive and corrosive
B. cohesive and adhesive
C. electrostatic and ionic
D. repellent and attractive

Correct answer: B

Rationale: Water is a polar molecule due to an uneven distribution of electrons, allowing it to form hydrogen bonds. This property makes water both cohesive (attracted to itself) and adhesive (attracted to other substances). Choice A is incorrect because water is not corrosive; rather, it is a solvent. Choices C and D are incorrect as they do not describe the cohesive and adhesive properties of water.