Biology Chapter 1.4: Prokaryotic Cells Quiz

Questions and Answers

What is the primary role of the conjugation bridge between bacterial cells?

To protect against viruses

To facilitate the transfer of genetic material (correct)

To transfer nutrients

To provide structural support

All bacteria can undergo the process of transformation.

False

What is the term for bacteria that contain the F (fertility) factor?

F+ cells

Bacteria can reproduce via _____ fission.

binary Signup and view all the answers

Match the following processes with their descriptions:

Conjugation = Transfer of genetic material through a pilus Transformation = Uptake of foreign DNA from the environment Transduction = Transfer of DNA by a virus Transposons = Genetic elements that can move within the genome Signup and view all the answers

What phenomenon occurs when a bacterium dies off due to lack of resources?

Death phase Signup and view all the answers

Viruses can reproduce independently of host cells.

False Signup and view all the answers

Which specific plasmid is best-studied for its role in bacterial conjugation?

F factor Signup and view all the answers

During the _____ phase, bacteria adapt to new environmental conditions.

lag Signup and view all the answers

What is a consequence of patients not completing antibiotic treatments?

Development of antibiotic resistance in surviving bacteria Signup and view all the answers

What is the primary method of reproduction for prokaryotic cells?

Binary fission Signup and view all the answers

Prokaryotic cells can acquire and use genetic material from inside the cell only.

False Signup and view all the answers

What are plasmids and why are they important for bacteria?

Plasmids are extrachromosomal DNA that often carry genes for antibiotic resistance and virulence factors. Signup and view all the answers

In binary fission, the circular chromosome _____ to produce two identical daughter cells.

replicates Signup and view all the answers

Match the following terms with their descriptions:

Binary Fission = Asexual reproduction method in prokaryotes Transformation = Integration of foreign genetic material Episomes = Plasmids capable of integrating into host genome Transduction = Genetic recombination via bacteriophages Signup and view all the answers

Which of the following is NOT a process of bacterial genetic recombination?

Mitosis Signup and view all the answers

E. coli can replicate every 20 minutes under ideal growth conditions.

True Signup and view all the answers

What is the role of plasmids in bacterial cells?

Plasmids carry genes that provide benefits such as antibiotic resistance and increased pathogenicity. Signup and view all the answers

Bacterial genetic _____ helps increase diversity and promotes evolution.

recombination Signup and view all the answers

Which of the following is a benefit of genetic recombination in bacteria?

Antibiotic resistance Signup and view all the answers

Study Notes

Prokaryotic vs. Eukaryotic Cells

Prokaryotic cells differ structurally and biochemically from eukaryotic cells.
Prokaryotes reproduce asexually through binary fission, a process that is simpler and faster than mitosis.

Binary Fission

Involves the circular chromosome attaching to the cell wall and replicating during cell growth.
As the cell enlarges, the plasma membrane and cell wall grow inward, resulting in two identical daughter cells.
Under ideal growth conditions, some E. coli strains can replicate every 20 minutes.

Genetic Recombination

Prokaryotic cells typically have a single circular chromosome, with many also containing plasmids—extrachromosomal DNA that provides beneficial traits such as antibiotic resistance.
Plasmids can carry virulence factors that enhance pathogenicity, including toxin production and traits that evade the immune system.
Episomes are plasmids that can integrate into the bacterial genome.

Mechanisms of Genetic Recombination

Bacterial diversity is increased through transformation, conjugation, and transduction.

Transformation

Involves the uptake of foreign genetic material from lysed neighboring bacteria into the host genome.
Commonly occurs in gram-negative rods.

Conjugation

Bacterial mating involves forming a conjugation bridge for unidirectional transfer of genetic material.
Donor cells (F+) possess the sex factor plasmid; recipient cells (F–) do not.
The F factor in E. coli is a well-studied example.
During conjugation, F+ cells replicate and donate F factors, converting F– to F+ and allowing further plasmid transfer.

Transduction

Unique in requiring a vector (bacteriophage) to transfer DNA from one bacterium to another.
Bacteriophages may inadvertently include bacterial DNA during assembly, which is then transferred to a new host.

Transposons

Genetic elements that can move within the genome, possibly disrupting gene function if inserting in coding regions.

Real World Implications

Incomplete antibiotic courses can lead to increased antibiotic resistance by leaving behind resistant bacteria that proliferate.
Increased resistance complicates treatment of common infections.

Bacterial Growth Phases

Bacterial growth follows a series of phases: lag phase (adaptation), exponential/log phase (rapid division), stationary phase (resource depletion slows reproduction), and death phase (resource exhaustion).
The bacterial growth curve is a semilog plot, indicating the exponential increase during the growth phases.

Bacterial Growth Curve

A straight line on a semilog plot during the exponential phase reflects a true exponential increase, not a linear one.

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Description

Test your knowledge on prokaryotic cells and their asexual reproduction methods, particularly binary fission. This quiz covers the structural and biochemical differences between prokaryotes and eukaryotes, along with the mechanisms of genetic material acquisition. Prepare to explore the fascinating world of microorganisms!