Q: A red blood cell is placed in a 0.3 M NaCl solution at 37°C. Calculate the solute potential ($$\Psi_s) $$using the formula $$\Psi_s = -iCRT$$. ($$i = 2$$, $$C = 0.3$$ mol/L, $$R = 0.0831 L$$·bar/mol·K, $$T = 310 K). $$Which value is correct?

$$\Psi_s = -2 \times 0.3 \times 0.0831 \times 310 = -15.47$$ bar

Question 1

Which of the following best explains why eukaryotic cells can grow larger and more complex than prokaryotic cells?

Accepted Answer

Eukaryotic cells contain membrane-bound organelles that compartmentalize functions, increasing efficiency.

Question 2

A scientist is studying a cell that contains ribosomes, a plasma membrane, and a nucleoid region, but no membrane-bound organelles. Which type of cell is this most likely to be?

Accepted Answer

Prokaryotic cell

Question 3

Which of the following best describes the function of the rough endoplasmic reticulum (RER)?

Accepted Answer

Synthesizes proteins that are secreted or inserted into membranes

Question 4

A mutation causes a cell to produce nonfunctional aquaporins. Which process would be most directly affected?

Accepted Answer

Facilitated diffusion of water across the plasma membrane

Question 5

Which of the following best explains why small cells are more efficient at exchanging materials with their environment than large cells?

Accepted Answer

Small cells have a higher surface area-to-volume ratio, maximizing exchange across the plasma membrane.

Question 6

A plant cell is placed in a hypotonic solution. What will most likely happen to the cell?

Accepted Answer

The cell will become turgid as water enters, but the cell wall prevents bursting.

Question 7

Which of the following best describes the structure of a phospholipid bilayer in a plasma membrane?

Accepted Answer

Hydrophilic heads face the exterior and interior, while hydrophobic tails face each other in the middle.

Question 8

Which of the following molecules would most easily diffuse through a plasma membrane without the help of a transport protein?

Accepted Answer

Oxygen ($$\mathrm{O_2$})$$

Question 9

A cell is actively transporting potassium ions ($$\mathrm{K^+}) $$into the cytoplasm against their concentration gradient. Which of the following statements is true?

Accepted Answer

This process requires ATP and is an example of active transport.

Question 10

Which of the following best explains the endosymbiotic theory for the origin of mitochondria and chloroplasts?

Accepted Answer

They originated as free-living prokaryotes that were engulfed by ancestral eukaryotic cells.

Question 11

A red blood cell is placed in a 0.3 M NaCl solution at 37°C. Calculate the solute potential ($$\Psi_s) $$using the formula $$\Psi_s = -iCRT$$. ($$i = 2$$, $$C = 0.3$$ mol/L, $$R = 0.0831 L$$·bar/mol·K, $$T = 310 K). $$Which value is correct?

Accepted Answer

$$\Psi_s = -2 	imes 0.3 	imes 0.0831 	imes 310 = -15.47$$ bar

Question 12

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

Accepted Answer

It increases membrane fluidity at low temperatures and decreases fluidity at high temperatures.

Question 13

Which of the following scenarios best illustrates the process of exocytosis?

Accepted Answer

A neuron releases neurotransmitters into a synaptic cleft.

Question 14

Which of the following statements about facilitated diffusion is correct?

Accepted Answer

It uses carrier or channel proteins to move substances down their concentration gradient.

Question 15

A cell is placed in a solution and water moves into the cell. Which of the following best describes the tonicity of the solution relative to the cell?

Accepted Answer

The solution is hypotonic to the cell.

Question 16

Which of the following best explains why the inner mitochondrial membrane is highly folded?

Accepted Answer

To increase the surface area for ATP production during cellular respiration.

Question 17

Which of the following is a function of the cytoskeleton in eukaryotic cells?

Accepted Answer

Providing structural support and facilitating cell movement

Question 18

Which of the following best describes the difference between passive and active transport?

Accepted Answer

Passive transport moves substances down their concentration gradient without energy input, while active transport requires energy to move substances against the gradient.

Question 19

Which of the following best explains why plant cells have both chloroplasts and mitochondria?

Accepted Answer

Chloroplasts produce glucose through photosynthesis, while mitochondria break down glucose to produce ATP.

Cell Structure, Membrane Function, and Transport: General Biology Study Notes

Guida di studio - Domande di pratica

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