Biology Practice Test - Nurselytic

Correct Answer: A

Rationale: Microtubules are fundamental components of the cytoskeleton in a cell, playing a crucial role in providing structural support and maintaining the cell's shape. They are composed of tubulin protein subunits and are involved in various cellular processes like cell division, intracellular transport, and cell motility. Microfilaments, on the other hand, are involved in cell movement and maintaining cell shape but are not primarily responsible for supporting the cell's overall structure. Cilia and microvilli are cellular projections that aid in movement and absorption, respectively, but they do not play a significant role in providing structural support to the cell.

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.

Correct Answer: D

Rationale: The main objective of the translation stage of protein synthesis is to produce proteins. During translation, ribosomes decode mRNA sequences to synthesize proteins by linking amino acids together.
Choice A, '
To produce amino acids,' is incorrect as amino acids are the building blocks of proteins and are not produced during translation.

Choices B and C, '
To produce nucleotides' and '
To produce fatty acids,' are also incorrect as these molecules are not the direct products of the translation stage of protein synthesis.

Correct Answer: D

Rationale: Cholesterol helps to maintain the fluidity and stability of the cell membrane by fitting between the phospholipid molecules.
Choice A is incorrect because cholesterol does not build up fats in the cell membrane.
Choice B is incorrect as protein channels are formed by proteins, not cholesterol.
Choice C is incorrect as cholesterol actually helps regulate the fluidity of the membrane, making it less rigid and more permeable.

Correct Answer: B

Rationale: The correct answer is B: Consuming. Phagocytes are cells that engulf and digest pathogens, dead cells, and other harmful particles, playing a crucial role in the immune system's defense. Phagocytes do not secrete substances, alter particles, or build structures; their primary function is to consume and eliminate harmful entities.