Question 1

Which of the following features is unique to prokaryotic cells such as $$E.\ coli$$ and not found in typical eukaryotic cells?

Accepted Answer

Circular DNA located in the nucleoid region

Question 2

A scientist is comparing the cell walls of a bacterium, a plant, and a fungus. Which statement correctly matches the primary component of each cell wall?

Accepted Answer

Bacteria: peptidoglycan; Plants: cellulose; Fungi: chitin

Question 3

Which of the following best describes the function of glycoproteins on the cell membrane surface?

Accepted Answer

They serve as recognition sites for cell-cell interactions and signaling.

Question 4

A red blood cell is placed in a solution and swells until it bursts. Which type of solution was the cell placed in, and what is the underlying process?

Accepted Answer

Hypotonic solution; water enters the cell by osmosis

Question 5

Which of the following is an example of active transport across the plasma membrane?

Accepted Answer

Sodium-potassium pump moving Na$$^+$$ out and K$$^+ in $$against their gradients

Question 6

Which statement correctly distinguishes between endocytosis and exocytosis?

Accepted Answer

Endocytosis involves the cell membrane engulfing material to bring it inside, while exocytosis releases material outside the cell.

Question 7

Which of the following best describes the structure of the plasma membrane according to the fluid mosaic model?

Accepted Answer

A double layer of phospholipids with embedded proteins that move laterally

Question 8

Which of the following is NOT a function of the cytoskeleton in eukaryotic cells?

Accepted Answer

Synthesizing ATP during cellular respiration

Question 9

A cell is observed to engulf a large bacterium by wrapping its membrane around it and forming a vesicle. Which specific type of endocytosis is this?

Accepted Answer

Phagocytosis

Question 10

Which of the following best explains why facilitated diffusion is considered a passive process?

Accepted Answer

It uses membrane proteins to move molecules down their concentration gradient without energy input.

Question 11

Which of the following is a correct comparison between prokaryotic and eukaryotic cells?

Accepted Answer

Eukaryotic cells have their DNA enclosed in a nucleus, while prokaryotic cells have DNA in the nucleoid region.

Question 12

A cell is placed in a solution with a solute concentration of 0.2 M. The cytoplasm has a solute concentration of 0.5 M. What will happen to the cell, and why?

Accepted Answer

Water will move into the cell because the solution is hypotonic.

Question 13

Which of the following best describes the role of cholesterol in the plasma membrane?

Accepted Answer

It stabilizes membrane fluidity across temperature changes.

Question 14

Which process is responsible for the uptake of specific molecules, such as LDL cholesterol, via binding to cell surface receptors?

Accepted Answer

Receptor-mediated endocytosis

Question 15

Which of the following statements about osmosis is correct?

Accepted Answer

Osmosis is the diffusion of water across a selectively permeable membrane.

Question 16

A cell uses the sodium-potassium pump to maintain its internal environment. Which equation best represents the stoichiometry of this pump per ATP hydrolyzed?

Accepted Answer

$$2\ \mathrm{K}^+\ 	ext{in},\ 3\ \mathrm{Na}^+\ 	ext{out}$$

Question 17

Which of the following is a real-life example of exocytosis in human physiology?

Accepted Answer

Release of insulin from pancreatic beta cells

Question 18

Which of the following best explains why plant cells do not burst when placed in a hypotonic solution, unlike animal cells?

Accepted Answer

Plant cells have a rigid cell wall that prevents excessive expansion.

Question 19

Which of the following is NOT a component of the eukaryotic cytoskeleton?

Accepted Answer

Peptidoglycan

Question 20

A cell is observed to move a large quantity of glucose from an area of low concentration to an area of high concentration. Which process is responsible for this movement?

Accepted Answer

Active transport

Cell Structure, Membrane Transport, and Endocytosis/Exocytosis in General Biology

Guida di studio - Domande di pratica

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