synthesis of carbohydrates lipids and steroid hormones are functions of which of the following

HESI RN

Biology Practice Test

1. Which of the following is responsible for the synthesis of carbohydrates, lipids, and steroid hormones?

A. Smooth endoplasmic reticulum (ER)
B. Rough endoplasmic reticulum (ER)
C. Golgi apparatus
D. Ribosomes

Correct answer: A

Rationale: The smooth endoplasmic reticulum (ER) is the correct answer. It is responsible for the synthesis of lipids, including steroids, and also plays a role in carbohydrate metabolism. The rough endoplasmic reticulum (ER) is involved in protein synthesis and processing, not lipid or carbohydrate synthesis. The Golgi apparatus is responsible for modifying, sorting, and packaging of proteins and lipids, but not for their synthesis. Ribosomes are the cellular organelles responsible for protein synthesis, not lipid or carbohydrate synthesis.

2. Where can ribosomes be found inside a cell?

A. Attached to the endoplasmic reticulum (ER) and in the cytoplasm
B. Within the cellular membrane
C. Attached to the Golgi apparatus and in the cytoplasm
D. Within the nucleus

Correct answer: A

Rationale: Ribosomes can be found attached to the endoplasmic reticulum (ER) or free-floating in the cytoplasm. The correct answer is A because ribosomes are responsible for synthesizing proteins and are commonly found on the ER or in the cytoplasm. Choice B is incorrect because ribosomes are not typically located within the cellular membrane. Choice C is incorrect as ribosomes are not attached to the Golgi apparatus; instead, they are involved in protein synthesis. Choice D is incorrect as ribosomes are not found within the nucleus but rather in the cytoplasm or attached to the ER.

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. Water is held together by which of the following bonds?

A. Electrostatic attraction
B. Van der Waals forces
C. Hydrogen
D. Oxygen

Correct answer: C

Rationale: Water molecules are held together by hydrogen bonds, which are weak bonds formed between the slightly positive hydrogen atom of one water molecule and the slightly negative oxygen atom of another. Choice A, electrostatic attraction, is a general term for the attraction between opposite charges but does not specifically describe the bonds in water. Choice B, Van der Waals forces, are weak intermolecular forces that arise from temporary fluctuations in electron distribution, not the primary bonds in water. Choice D, oxygen, is incorrect as oxygen is part of the water molecule but not the bond holding water molecules together.

5. In DNA, the nucleotide base adenine always binds with which of the following?

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

Correct answer: C

Rationale: The correct answer is C: Thymine. In DNA, adenine always pairs with thymine, forming a base pair held together by hydrogen bonds. Guanine pairs with cytosine. Uracil is found in RNA, not DNA. Cytosine pairs with guanine. Therefore, option C is the correct pairing for adenine in DNA.