Question 1

Which of the following best describes the process of binary fission in prokaryotes?

Accepted Answer

A cell elongates, forms a septum, and splits into two identical daughter cells.

Question 2

During the bacterial cell cycle, which protein is primarily responsible for forming the ring that initiates cell division?

Accepted Answer

FtsZ

Question 3

Which phase of the eukaryotic cell cycle is characterized by DNA synthesis?

Accepted Answer

S phase

Question 4

A culture of E. coli starts with 10 cells and grows exponentially for 2 hours with a generation time of 30 minutes. How many cells will be present at the end? Use $$N = N_0$ 2^n.$$

Accepted Answer

$$N = 10 	imes 2^4$ = 160$$

Question 5

Which enzyme is responsible for unwinding the DNA double helix at the replication fork in bacteria?

Accepted Answer

Helicase

Question 6

In bacterial cell division, what is the role of Min proteins?

Accepted Answer

They ensure the divisome forms at the cell center.

Question 7

Which of the following is NOT a type of polar growth in prokaryotes?

Accepted Answer

Binary fission

Question 8

What is the function of transpeptidase (FtsI) in bacterial cell wall synthesis?

Accepted Answer

It inserts new peptidoglycan into the expanding cell wall by forming peptide cross-links.

Question 9

A batch culture is best described as:

Accepted Answer

A closed system with a fixed volume of culture medium.

Question 10

Which mathematical formula is used to calculate the final number of cells in exponential growth?

Accepted Answer

$$N = N_0$ 2^n$$

Question 11

Which phase of the microbial growth curve is characterized by the synthesis of enzymes necessary for biosynthesis?

Accepted Answer

Lag phase

Question 12

In the context of DNA replication, what is the role of primase?

Accepted Answer

It adds RNA primers to initiate DNA synthesis.

Question 13

Which of the following statements about peptidoglycan synthesis is correct?

Accepted Answer

Bactoprenol transports peptidoglycan precursors across the cytoplasmic membrane.

Question 14

A chemostat is used in microbiology to:

Accepted Answer

Maintain cell populations in exponential growth for long periods.

Question 15

Which protein directs the location of new cell wall synthesis in rod-shaped bacteria?

Accepted Answer

MreB

Question 16

If a culture of Vibrio natriegens starts with 7 cells and grows exponentially for 1 hour with a generation time of 10 minutes, how many cells will be present at the end? Use $$N = N_0$ 2^n.$$

Accepted Answer

$$N = 7 	imes 2^6$ = 448$$

Question 17

Which of the following is a consequence of an error in inserting new cell wall material during bacterial growth?

Accepted Answer

Autolysis (spontaneous cell lysis)

Question 18

Which phase of the microbial growth curve is associated with nutrient depletion and accumulation of toxic products?

Accepted Answer

Stationary phase

Question 19

In the replication of circular bacterial chromosomes, what is the function of Tus proteins?

Accepted Answer

They block progress of the replication fork at termination sites.

Question 20

Which of the following best explains why exponential growth of bacteria in food can lead to rapid spoilage?

Accepted Answer

The number of cells doubles at regular intervals, leading to a sudden increase in population.

Microbial Growth and Cell Division: Mechanisms and Patterns

Guida di studio - Domande di pratica

Study guide - Flashcard