where can ribosomes be found inside a cell

HESI RN

Biology Practice Test

1. 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.

2. The term pleiotropy is best defined as which of the following?

A. A situation in which one gene remains unexpressed
B. One gene influencing multiple, seemingly unrelated phenotypic traits
C. Two genes affected by a single allele
D. A condition in which multiple genes are missing

Correct answer: B

Rationale: Pleiotropy is best defined as one gene influencing multiple, seemingly unrelated phenotypic traits. This phenomenon showcases the multifunctionality of genes, where a single gene can have effects on various aspects of an organism's phenotype. Choices A, C, and D do not accurately capture the concept of pleiotropy. Option A refers to gene expression, not pleiotropy. Option C describes genetic interactions but not in the context of pleiotropy. Option D talks about missing genes, which is unrelated to the definition of pleiotropy.

3. 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.

4. What is the difference between DNA and RNA?

A. RNA has an extra Phosphate group
B. DNA has one less oxygen than RNA
C. RNA has one less oxygen than DNA
D. DNA has an extra sugar molecule

Correct answer: B

Rationale: The correct answer is B. DNA has one less oxygen atom in its sugar molecule (deoxyribose) compared to RNA, which has a ribose sugar. Choice A is incorrect because RNA does not have an extra phosphate group. Choice C is incorrect as RNA actually has one more oxygen atom than DNA. Choice D is incorrect as DNA and RNA have different sugar molecules, with DNA having deoxyribose and RNA having ribose.

5. Why does ice have the capability of floating on water?

A. It has a higher viscosity
B. It has a different chemical composition
C. It has a high specific heat
D. It forms a lattice when freezing

Correct answer: D

Rationale: The correct answer is D. Ice forms a lattice structure when it freezes, which makes it less dense than liquid water, allowing it to float. Choice A is incorrect because viscosity refers to a fluid's resistance to flow and is not related to ice floating. Choice B is incorrect as ice and liquid water have the same chemical composition (H2O). Choice C is incorrect because the high specific heat of water is not the reason why ice floats.