How Asexual Prokaryotes Achieve Genetic Diversity

Vertical gene transfer

the transmission of genetic information from generation to generation.

Horizontal Gene Transfer 

the introduction of genetic material from one organism to another organism within the same generation

in prokaryotes introduces genetic diversity, enabling gene sharing between species and influencing phenotypes. HGT, along with mutation, is a significant source of genetic variation in prokaryotes.

Transformation

the prokaryote takes up naked DNA found in its environment and that is derived from other cells that have lysed on death and released their contents, including their genome, into the environment; Mechanism of horizontal gene transfer in which naked environmental DNA is taken up by a bacterial cell

Transduction

Viruses that infect bacteria (bacteriophages) may also move short pieces of chromosomal DNA from one bacterium to another; Mechanism of horizontal gene transfer in bacteria in which genes are transferred through viral infection

Conjugation

DNA is directly transferred from one prokaryote to another;Transfer of DNA through direct contact using a conjugation pilus

Conjugation pillus

brings the organisms into contact with one another.

Transposition

Process whereby DNA independently excises from one location in a DNA molecule and integrates elsewhere

Transposons

are molecules of DNA that include special inverted repeat sequences at their ends and a gene encoding the enzyme transposase

What are Three Ways Sexual Reproduction Introduces Genetic Variation into Offspring

Independent Assortment, Crossing Over, and Random Fertilization:

What are Benefits of Asexual Reproduction

Fast and efficient reproduction without needing a mate

What are Three Mechanisms of Horizontal Gene Transfer in Prokaryotes

Transformation, Transduction, and Conjugation

Why Does a Bacterial Cell Make Environmental DNA Single-Stranded During Transformation?

It Facilitates its integration into the bacterial chromosome through homologous recombination and protects the cell by reducing the risk of double-stranded DNA triggering harmful immune-like responses.

What is the Agent of Transduction of Prokaryotic Cells?

A bacteriophage (virus that infects bacteria)

In Specialized Transduction, Where Does the Transducing Piece of DNA Come From?

comes from specific regions of the bacterial host genome that get mistakenly packaged into the phage during the improper excision of a prophage (integrated viral DNA).

What Type of Replication Occurs During Conjugation?

The Rolling circle replication: The donor plasmid is copied and transferred as a single strand into the recipient.

What Types of Traits Are Encoded on Plasmids?

• Antibiotic resistance (R-plasmids)

• Virulence factors (toxins, adhesion proteins)

• Metabolic capabilities (e.g., breaking down unusual substances)

• Conjugative functions (ability to form a pilus

What are Two Ways a Transposon Can Affect the Phenotype of a Cell It Moves To?

• Insertional mutagenesis: Disrupts a gene when it inserts into it, potentially inactivating important proteins.

• Gene activation or silencing: It can carry promoters that turn nearby genes on or off.