BIOL 1407: Lab #3-8

A bacteriophage is a

a virus that infects a bacterium

The bacterial flagellum moves

by rotation that is powered by the proton motive force.

Above 212 degrees F most bacteria are

destroyed

How is the movement of bacterial cells via flagella different from the movement of eukaryotic cells via flagella?

- Bacteria flagella: proton motive force - eukaryotic flagella: ATP hydrolysis

Bacterial conjugation

- direct contact btwn donor and recipient cells - shortening of the pilus - enzymatic cleavage of one strand at the origin of transfer - recipient cell becomes a donor cell after conjugation

If one donor cell is mixed with 20 recipient cells, eventually ________ cells will become donors.

20

Why do the flagella of gram-negative bacteria have a basal body with four rings, while the flagella of gram-positive bacteria have a basal body with only two rings?

Gram-negative bacteria have two cell-membranes and gram-positive bacteria have a single cell membrane

How is DNA replication during conjugation different from DNA replication preceding binary fission?

In conjugation, DNA replication involves only plasmid DNA, while replication proceeding binary fission involves chromosomal DNA

What is the biggest benefit of transformation to the bacterial cell?

The bacteria might acquire genes that make it better able to survive in its environment

Why do recipient cells become donor cells after conjugation has occurred?

They have received genes that have allowed them to produce a sex pilus

during bacterial conjugation, plasma replication occurs in

both the donor and recipient

The Gram Stain of a bacterial cell is based on the chemical properties of its

cell wall

the proper sequence of reagents in the Gram Stain procedure is

crystal violet, iodine, ethanol, safranin

With ideal environmental factors, the reproduction rate of bacteria is

extremely rapid

Many antibiotics work by preventing the proper synthesis of the peptidoglycan cell wall. These antibiotics are most likely to be effective against what types of bacteria?

gram positive bacteria

When a bacteriophage carrying bacterial DNA infects a new bacterium

it transfers bacterial DNA from the donor bacterium to the recipient bacterium

DNA transformation involves the transfer of DNA via

naked DNA in a solution

When DNA from an ampicillin resistant organism is brought into an ampicillin sensitive organism by transformation and the product is grown on agar containing ampicillin

only the transformed cells will grow

Why is most DNA acquired by transduction from the same species of bacteria?

phages are usually extremely host specific and can only infect a single bacterial species

What initiates the gliding motility in bacteria

specialized cell surface proteins and slimy polysaccharides

At freezing temperatures, most bacteria

stop growing, but are not dead.

The main environmental factors that affect mircroorganism growth include chemical inhibitors, oxygen, pH, nutrients, moisture, and

temperature

If DNA receptors on the cell surface of a bacterial cell were mutated and nonfunctional, how would that effect the bacterial cell?

the cell would be incapable of accepting naked DNA from the environment

When a recipient bacterial cell receives bacterial DNA via transduction

the new DNA is replicated every time the recipient multiplies