why do gardeners sometimes use salt to get rid of slugs

HESI A2

Biology HESI A2 Practice Exam

1. 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.

2. 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.

3. What is the purpose of phloem tissue in plant stems?

A. It conducts water up through the stem.
B. It conducts the energy of light to leaves.
C. It conducts food throughout the plant.
D. It conducts carbon dioxide throughout the plant.

Correct answer: C

Rationale: The purpose of phloem tissue in plant stems is to conduct food, particularly sugars produced in the leaves during photosynthesis, throughout the plant. The phloem transports these organic compounds to various parts of the plant where they are needed for growth and energy. Choice A is incorrect because water is primarily transported by xylem tissue, not phloem. Choice B is incorrect as the energy of light is captured by chlorophyll in the process of photosynthesis, not conducted by phloem. Choice D is incorrect because carbon dioxide is mainly absorbed through the leaves and transported to other parts of the plant through diffusion, not by phloem.

4. DNA bases include all but which of the following?

A. Adenine
B. Thymine
C. Uracil
D. Cytosine

Correct answer: C

Rationale: The correct answer is C: Uracil. Uracil is not a DNA base; it is a base found only in RNA. The four bases in DNA are Adenine, Thymine, Cytosine, and Guanine. Choice A, Adenine, is a correct DNA base. Choice B, Thymine, is a correct DNA base. Choice D, Cytosine, is a correct DNA base. Therefore, Uracil is the only incorrect choice among the options provided.

5. Which of the following arrangement is seen in the plasma membrane?

A. Lipids with embedded proteins
B. An outer lipid layer and an inner lipid layer
C. Proteins embedded in lipid bilayer
D. Altering protein and lipid layers

Correct answer: C

Rationale: The correct arrangement seen in the plasma membrane is proteins embedded in the lipid bilayer. The plasma membrane is composed of a lipid bilayer with embedded proteins. These proteins perform various functions such as transport, signaling, and structural support within the cell membrane. This arrangement allows for the selective permeability of the membrane and facilitates communication between the cell and its environment. Choices A, B, and D are incorrect because the primary arrangement in the plasma membrane involves proteins being embedded in the lipid bilayer, not lipids with embedded proteins, an outer and inner lipid layer, or altering protein and lipid layers.