HESI A2
Biology HESI A2 Practice Exam
1. Most enzymes are made up of what?
- A. proteins
- B. lipids
- C. starches
- D. simple sugars
Correct answer: A
Rationale: Most enzymes are made up of proteins. Proteins are large biomolecules composed of amino acids that are vital for the structure and function of enzymes. Enzymes act as catalysts in biochemical reactions, speeding up the rate of chemical reactions in living organisms. They exhibit high specificity and efficiency due to their unique protein structures. Lipids, starches, and simple sugars are not typically the primary components of enzymes, making them incorrect choices.
2. The mixture of gases surrounding a planet is referred to as its ______.
- A. Atmosphere
- B. Stratosphere
- C. Biosphere
- D. Troposphere
Correct answer: A
Rationale: The mixture of gases surrounding a planet is referred to as its atmosphere. The atmosphere plays a crucial role in supporting life on Earth by providing oxygen, regulating carbon dioxide levels, and shielding the planet from harmful radiation. While the stratosphere, troposphere, and other layers are part of the atmosphere, the term 'atmosphere' encompasses the entire gaseous envelope surrounding a planet. The stratosphere, troposphere, mesosphere, thermosphere, and exosphere are specific layers within the atmosphere, each with distinct characteristics and functions.
3. Why do gardeners sometimes use salt to get rid of slugs?
- A. The salt moves from the exterior into the slug’s body.
- B. The salt causes water in the slug to move outward.
- C. The salt and slug slime merge to form a new compound.
- D. The salt’s corrosiveness breaks down the slug’s cell walls.
Correct answer: D
Rationale: Gardeners use salt to get rid of slugs because salt is corrosive and breaks down the slug's cell walls. When the slug comes into contact with salt, the salt draws moisture out of the slug's body, causing dehydration and ultimately leading to the slug's death. Choices A, B, and C are incorrect because the primary mechanism of salt in eliminating slugs is its corrosive action on the slug's body, not the movement of salt into the slug's body, outward movement of water in the slug, or merging with slug slime to form a new compound.
4. Which of the following is a protein?
- A. cellulose
- B. hemoglobin
- C. estrogen
- D. ATP
Correct answer: B
Rationale: The correct answer is 'hemoglobin' because it is a protein that carries oxygen in the blood. Cellulose is a carbohydrate found in the cell walls of plants, not a protein. Estrogen is a hormone, not a protein. ATP (adenosine triphosphate) is a molecule that carries energy within cells, not a protein.
5. What is the correct order of the hierarchy of levels in the biological classification of organisms?
- A. Kingdom, phylum, class, order, family, genus, and species
- B. Phylum, kingdom, class, order, family, genus, and species
- C. Order, phylum, class, kingdom, family, genus, and species
- D. Kingdom, phylum, order, class, family, genus, and species
Correct answer: A
Rationale: The correct order of the hierarchy of levels in the biological classification of organisms is Kingdom, Phylum, Class, Order, Family, Genus, and Species. This order is based on the Linnaean system of classification, with each level representing a progressively more specific grouping of organisms. Choice B is incorrect because it starts with Phylum instead of Kingdom. Choice C is incorrect as it places Order before Phylum. Choice D is incorrect because it does not follow the correct order of the biological classification hierarchy.
Similar Questions
Access More Features
HESI A2 Basic
$49/ 30 days
- 3,000 Questions with answers
- 30 days access
HESI A2 Premium
$99/ 90 days
- Actual HESI A2 Questions
- 3,000 questions with answers
- 90 days access