Question 1

Which of the following is NOT one of the four characteristics shared by all living things?

Accepted Answer

Presence of a cell wall

Question 2

A scientist is examining a cell under a microscope. The cell has a nucleus, mitochondria, and a plasma membrane, but no peptidoglycan in its cell wall. To which domain does this cell most likely belong?

Accepted Answer

Eukarya

Question 3

Which of the following best describes the difference between a capsule and a slime layer in prokaryotic glycocalyces?

Accepted Answer

Capsules are firmly attached and organized, while slime layers are loosely attached and unorganized.

Question 4

Which of the following statements about biofilms is CORRECT?

Accepted Answer

Biofilms are communities of microorganisms attached to a surface and embedded in a self-produced matrix.

Question 5

A bacterium uses its flagella to move toward a nutrient source. Which of the following structures is primarily responsible for this movement?

Accepted Answer

Flagella

Question 6

Which of the following is a key difference between Gram-positive and Gram-negative bacterial cell walls?

Accepted Answer

Gram-positive cell walls contain a thick layer of peptidoglycan, while Gram-negative cell walls have a thin layer of peptidoglycan and an outer membrane.

Question 7

Where does most metabolic activity occur in a Gram-negative bacterial cell wall?

Accepted Answer

In the periplasmic space

Question 8

A patient sample contains bacteria with cell walls rich in mycolic acids, making them resistant to decolorization by acid-alcohol. Which type of organism is this?

Accepted Answer

Acid-fast

Question 9

Which of the following best describes the structure of the plasma membrane?

Accepted Answer

A double layer of phospholipids with embedded proteins

Question 10

Which transport process requires energy in the form of ATP and moves substances against their concentration gradient?

Accepted Answer

Active transport

Question 11

When E. coli cells are exposed to a hypertonic solution, they produce a transporter protein that moves $$K^+$$ ions into the cell. Why is this process necessary?

Accepted Answer

To increase the internal solute concentration and prevent excessive water loss

Question 12

Which method of transport is used by eukaryotic cells but NOT by prokaryotic cells?

Accepted Answer

Endocytosis

Question 13

Which of the following is a membrane-bound organelle found in eukaryotic cells but NOT in prokaryotic cells?

Accepted Answer

Nucleus

Question 14

Why are ribosomes found in both prokaryotic and eukaryotic cells?

Accepted Answer

They are involved in protein synthesis, which is essential for all living cells.

Question 15

Which of the following statements best summarizes the endosymbiotic theory?

Accepted Answer

Eukaryotic cells evolved from prokaryotic cells by acquiring membrane-bound organelles through symbiosis.

Question 16

Which of the following is considered evidence supporting the endosymbiotic theory?

Accepted Answer

Mitochondria and chloroplasts contain their own circular DNA similar to bacterial DNA.

Question 17

Which of the following correctly lists the steps in endospore formation in the correct order?

Accepted Answer

DNA replication, septum formation, forespore development, cortex formation, spore coat synthesis, release of endospore

Question 18

What is the primary purpose of an endospore in bacteria?

Accepted Answer

To allow bacteria to survive harsh environmental conditions

Question 19

A researcher is studying a bacterial infection and finds that the bacteria are resistant to many antibiotics due to the presence of an outer membrane. Which type of bacteria is most likely responsible?

Accepted Answer

Gram-negative bacteria

Question 20

Which of the following best explains why active transport is necessary for a cell to accumulate nutrients from a low-concentration environment?

Accepted Answer

Active transport uses energy to move substances against their concentration gradient.

Question 21

A patient is diagnosed with tuberculosis. The causative agent, Mycobacterium tuberculosis, is difficult to treat because of its cell wall. Which feature of its cell wall is responsible for this resistance?

Accepted Answer

A waxy layer rich in mycolic acids

Cell Structure and Function: Study Guide (Chapter 3)

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