PowerPoint 3a - The Cell copy

Microorganisms

Diverse microscopic organisms that vary in size, shape, and metabolic capabilities.

Spontaneous Generation

The outdated theory that living organisms could arise from nonliving matter.

Francesco Redi

An Italian scientist who disproved spontaneous generation through an experiment with meat and maggots.

Biogenesis

The principle that life arises from existing living organisms, contrary to the idea of spontaneous generation.

Louis Pasteur

A French chemist who debunked spontaneous generation and developed pasteurization.

Cell Theory

The scientific theory that all living organisms are composed of cells, which are the basic units of life.

Prokaryotic Cells

Cells that lack a true membrane-bound nucleus and organelles, characteristic of bacteria and archaea.

Eukaryotic Cells

Cells that contain a membrane-bound nucleus and organelles, found in plants, animals, fungi, and protists.

Osmosis

The movement of water across a semipermeable membrane from an area of low solute concentration to an area of high solute concentration.

Endospores

Resistant structures formed by some bacteria to survive unfavorable conditions.

Sporulation

The process by which a vegetative bacterial cell forms an endospore.

Inclusions

Reserve deposits of nutrients found in the cytoplasm of prokaryotic cells.

Plasmids

Small circular strands of extrachromosomal DNA in prokaryotic cells that can carry advantageous genes.

Ribosomes

Cellular structures where protein synthesis occurs, made of rRNA and proteins.

Germ Theory of Disease

The theory that specific diseases are caused by specific microorganisms.

Aseptic Techniques

Procedures used to prevent contamination by pathogens.

Fermentation

The chemical breakdown of a substance by microorganisms, typically resulting in alcohol or acid.

Miasma Theory

The historical belief that diseases were caused by 'bad air' or noxious fumes.

Microbial Fermentation

The process whereby microorganisms convert sugars to acids, gases, or alcohol.

Endosymbiotic Theory

The theory suggesting mitochondria and chloroplasts originated from free-living bacteria.

Nucleoid Region

The area in prokaryotic cells where the circular DNA molecule is located, not enclosed by a membrane.