Question 1

Which of the following best explains why phospholipids are essential for cell membrane structure?

Accepted Answer

They are amphipathic, containing both hydrophilic heads and hydrophobic tails, allowing them to form bilayers in aqueous environments.

Question 2

A patient is given an intravenous solution that is hypertonic relative to their blood plasma. What is the most likely effect on their red blood cells?

Accepted Answer

Water will leave the cells, causing them to shrink (crenate).

Question 3

Which of the following best describes the difference between starch and cellulose?

Accepted Answer

Starch has alpha glycosidic bonds, making it digestible by humans, while cellulose has beta glycosidic bonds, making it indigestible for most animals.

Question 4

A scientist wants to observe the surface details of a virus particle. Which type of microscope should they use and why?

Accepted Answer

Scanning electron microscope (SEM), because it provides detailed 3D images of surfaces.

Question 5

Which of the following statements about the sodium-potassium pump is correct?

Accepted Answer

It uses ATP to move 3 sodium ions out of the cell and 2 potassium ions into the cell, creating an electrochemical gradient.

Question 6

Which of the following best explains why enzymes are specific to their substrates?

Accepted Answer

The active site of an enzyme has a unique shape that fits only specific substrates, like a key fitting a lock.

Question 7

A mutation causes a protein to lose its tertiary structure but retain its primary and secondary structures. Which of the following is most likely to occur?

Accepted Answer

The protein will lose its specific function because the overall 3D shape is necessary for activity.

Question 8

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

Accepted Answer

Prokaryotic cells lack membrane-bound organelles, while eukaryotic cells have compartmentalized organelles.

Question 9

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

Accepted Answer

It is studded with ribosomes and is involved in the synthesis and modification of proteins for secretion or membrane insertion.

Question 10

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

Accepted Answer

Water will enter the cell, causing it to become turgid (firm) due to the cell wall preventing bursting.

Question 11

Which of the following best describes the role of cholesterol in animal cell membranes?

Accepted Answer

It helps maintain membrane fluidity by preventing membranes from getting too solid in cold or too fluid in heat.

Question 12

Which of the following is a correct pairing of a macromolecule and its monomer?

Accepted Answer

Protein – amino acid

Question 13

Which of the following best explains why water moves through aquaporins in the cell membrane?

Accepted Answer

Aquaporins are channel proteins that facilitate the diffusion of water across the membrane.

Question 14

Which of the following statements about facilitated diffusion is correct?

Accepted Answer

It moves substances down their concentration gradient with the help of transport proteins, without using energy.

Question 15

Which of the following best describes the function of lysosomes in animal cells?

Accepted Answer

They contain hydrolytic enzymes that digest macromolecules and recycle cellular components.

Question 16

A cell is exposed to a toxin that inhibits the function of ribosomes. Which process will be most directly affected?

Accepted Answer

Protein synthesis

Question 17

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

Accepted Answer

Active transport requires energy (usually ATP) to move substances against their concentration gradient, while passive transport does not require energy and moves substances down their gradient.

Question 18

Which of the following best explains the function of tight junctions in animal cells?

Accepted Answer

They prevent leakage of extracellular fluid between adjacent cells.

Question 19

Which of the following best describes the structure of DNA?

Accepted Answer

A double helix with two antiparallel strands held together by hydrogen bonds between complementary bases.

Question 20

A cell is placed in a solution and water moves into the cell, causing it to swell. Which of the following equations best represents the relationship between solute concentration and water potential in this scenario?

Accepted Answer

$$ \Psi = \Psi_s + \Psi_p $$

General Biology Study Guide: Macromolecules, Cells, Membranes, and Cell Communication

Guida di studio - Domande di pratica

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