Chapter 27 BIO Vocabulary Definitions (Simplified)

Prokaryotes

Tiny, single-celled organisms without a nucleus, like bacteria and archaea.

Peptidoglycan

A strong material in bacterial cell walls that helps protect them.

Capsule

A sticky outer layer some bacteria have to help them stick to surfaces and avoid danger.

Endospores

A tough, protective shell that bacteria can form to survive harsh conditions.

Fimbriae

Short, hair-like structures that help bacteria stick to things.

Taxis

Movement toward or away from something, like food or light.

Flagella

Long, whip-like structures that help bacteria swim.

Nucleoid

The area inside a prokaryote where its DNA is found (not in a nucleus).

Plasmids

Small circles of extra DNA in bacteria that can carry useful genes.

Recombination

Mixing of genetic material to create new combinations.

Transformation

When bacteria take in free DNA from their surroundings.

Transduction

When viruses accidentally move DNA between bacteria.

Conjugation

When one bacterium transfers DNA to another through a special bridge.

F factor

A gene that helps bacteria form a bridge for DNA transfer (used in conjugation).

R plasmids

Special plasmids that carry genes for antibiotic resistance.

Nitrogen fixation

The process of converting nitrogen from the air into a form plants can use.

Biofilms

Groups of bacteria that stick together and form a slimy layer on surfaces.

Proteobacteria

A large, diverse group of bacteria, including some that cause diseases.

Chlamydias

Bacteria that only live inside animal cells and can cause infections.

Spirochetes

Spiral-shaped bacteria, some of which cause diseases like Lyme disease.

Cyanobacteria

Bacteria that make their own food using sunlight (like plants).

Gram-positive bacteria

A group of bacteria with thick cell walls that stain purple in tests.

Archaea

A type of prokaryote that looks like bacteria but is genetically different.

Extremophiles

Prokaryotes that live in extreme conditions.

Halophiles

Prokaryotes that live in very salty places.

Thermophiles

Prokaryotes that live in very hot places.

Methanogens

Archaea that make methane gas and live without oxygen.

TACK

A major group of archaea that includes Thermophiles, Archaea, Crenarchaeota, and Korarchaeota.

Symbiosis

A close relationship between two different organisms.

Exotoxins

Poisonous substances bacteria release to harm other cells.

Endotoxins

Toxins inside bacteria that are only released when they die.

Bioremediation

Using bacteria to clean up pollution in the environment.