Nursing Elites

1. Why do cells need to use exocytosis?

• A. To obtain energy
• B. To defend against invaders
• C. To remove waste products
• D. To undergo division

Correct answer: C

Rationale: Cells need to use exocytosis to remove waste products from the cell. Exocytosis is a process where cells release molecules or substances outside the cell by fusing vesicles with the cell membrane. This process is crucial for maintaining cellular homeostasis by efficiently eliminating waste materials. Choices A, B, and D are incorrect because exocytosis is specifically involved in the expulsion of molecules, not for obtaining energy, defending against invaders, or cell division.

2. Which type of passive transport uses proteins that change shape to move a target molecule through the membrane?

• A. Diffusion
• B. Carrier proteins
• C. Channel proteins
• D. None of the above

Correct answer: B

Rationale: The correct answer is B: Carrier proteins. Carrier proteins are involved in facilitated diffusion, a type of passive transport where specific target molecules are moved across the membrane with the help of proteins that change shape. These carrier proteins bind to the target molecule on one side of the membrane, undergo a conformational change, and then release the molecule on the other side. This process is crucial for the selective transport of certain molecules that cannot pass through the membrane by simple diffusion. Choices A and C are incorrect because diffusion and channel proteins do not involve proteins that change shape to transport target molecules selectively. Choice D is incorrect as carrier proteins fit the description provided in the question.

3. Why does cytokinesis happen?

• A. DNA can duplicate
• B. Organelles can convert energy
• C. Bacteria can be killed
• D. Daughter cells can divide

Correct answer: D

Rationale: Cytokinesis happens at the end of mitosis to physically separate the newly formed daughter cells. This allows the cell to divide into two separate daughter cells, each containing a complete set of genetic material (DNA) and organelles. The purpose of cytokinesis is to ensure that each daughter cell receives the necessary components to function independently. Choices A, B, and C are incorrect because cytokinesis does not directly involve DNA duplication, organelles converting energy, or killing bacteria.

4. Which is a byproduct of fermentation in muscle cells?

• A. Ethanol
• B. Pyruvic acid
• C. Lactic acid
• D. Oxygen

Correct answer: C

Rationale: Lactic acid is a byproduct of fermentation in muscle cells. During intense exercise or when oxygen is limited, muscle cells use anaerobic respiration to generate energy. This process breaks down glucose into lactic acid, which can cause muscle fatigue and soreness. Choice A, Ethanol, is not produced in muscle cells during fermentation. Choice B, Pyruvic acid, is an intermediate product in glucose metabolism but is not a byproduct of fermentation in muscle cells. Choice D, Oxygen, is not a byproduct of fermentation but a reactant in aerobic respiration.

5. Why are bacteria and blue-green algae often classified together?

• A. Both are gymnosperms.
• B. Both are prokaryotes.
• C. Both are autotrophs.
• D. Both are pathogens.

Correct answer: B

Rationale: Bacteria and blue-green algae (cyanobacteria) are often classified together because they are both prokaryotes. Prokaryotes are unicellular organisms that lack a membrane-bound nucleus and other membrane-bound organelles. This characteristic distinguishes them from eukaryotic organisms, which have these membrane-bound structures. Choice A is incorrect because gymnosperms are seed-producing plants with naked seeds, not bacteria or blue-green algae. Choice C is incorrect because being an autotroph (able to produce its own food) is not a reason for classifying them together. Choice D is incorrect because not all bacteria and blue-green algae are pathogens; many of them are beneficial or neutral to other organisms.

Similar Questions