Bacteria and Viruses: Structure, Reproduction, and Differences

What are prokaryotes?

Unicellular organisms that lack a nucleus and membrane-bound organelles.

What are the two domains of prokaryotes?

Bacteria and Archaea.

What is the main component of bacterial cell walls?

Peptidoglycan.

What are extremophiles?

Ancient prokaryotes that thrive in extreme environments.

What is the function of the capsule in bacteria?

Protects the bacteria from drying out and shields against antibiotics.

What are the three main shapes of bacteria?

Cocci (spheres), Bacilli (rods), Spirilli/Spirochetes (spirals).

What is binary fission?

A fast asexual reproduction method where DNA copies itself and the cell splits into two identical cells.

What is conjugation in bacteria?

A process where pili connect two bacterial cells to transfer plasmid DNA.

What are heterotrophs?

Organisms that eat other organisms, including decomposers and pathogens.

What is a virus?

A submicroscopic, infectious agent that requires a host to survive and multiply.

Why are viruses considered non-living?

They lack cellular structure, metabolism, and cannot reproduce independently.

What is the genetic core of a virus?

The part that contains the genetic material (DNA or RNA) for making new viruses.

What is the lytic cycle?

A viral life cycle resulting in immediate infection and destruction of the host cell.

What is the lysogenic cycle?

A dormant viral life cycle where viral DNA integrates into the host's chromosome.

What is the role of spikes on a virus?

They help the virus attach to specific receptors on host cells.

What is a bacteriophage?

A virus that exclusively infects bacteria.

How do antibiotics affect bacteria?

They effectively treat bacterial infections but do nothing against viruses.

What are photoautotrophs?

Bacteria that use sunlight to make their own food and release oxygen.

What are obligate anaerobes?

Bacteria that cannot survive in the presence of oxygen.

What is the function of pili in bacteria?

Help the cell attach to surfaces and transfer DNA.

What is the difference between bacteria and viruses in terms of size?

Bacteria are generally 10 to 100 times larger than viruses.

What is the role of the viral envelope?

An outer lipid membrane that some viruses acquire from the host cell.

What is the function of ribosomes in prokaryotic cells?

Used for protein synthesis.

What are facultative anaerobes?

Bacteria that can live with or without oxygen.

What is the role of the nucleoid in prokaryotic cells?

The region where the cell's circular DNA freely floats.

What are chemoautotrophs?

Bacteria that make their own food using chemicals like sulfur or nitrogen.