protists

Protists

A diverse group of eukaryotic organisms that are predominantly unicellular, microscopic, and not classified as plants, animals, or fungi.

Algae

Photosynthetic protists that are similar to plants, found in various aquatic environments.

Amoebas

Protists that move and ingest food using pseudopodia.

Plasmodium

A parasitic protist that causes malaria.

Slime Molds

Protists that exist as gelatinous masses during their lifecycle, often decomposers in ecosystems.

Diatoms

Protists with silica-rich cell walls, playing a crucial role in aquatic food webs.

Dinoflagellates

Bioluminescent, photosynthetic protists found in marine environments.

Giant Amoeba

An exception to typical protist characteristics, exhibiting unique size and habitat traits.

Caulerpa

A type of protist that challenges typical protist definitions due to its size and habitat.

Red Algae (Seaweed)

Protists that do not align with typical protist constraints in size or habitat.

Photoautotrophs

Protists that use photosynthesis to store energy.

Heterotrophs

Protists that consume organic matter for energy.

Mixotrophs

Protists that combine photosynthesis with the ingestion of organic matter.

Flagella

Whip-like structures used by protists for movement.

Cilia

Hair-like structures that beat in a coordinated manner to enable movement.

Pseudopodia

Extensions of the protist's cell used to anchor and move the organism forward.

Taxis

Movement of a protist toward or away from a stimulus.

Asexual Reproduction

Reproduction where protists produce two identical daughter cells, typically via binary fission.

Sexual Reproduction

Reproduction that involves genetic recombination, often triggered by nutrient depletion.

Aquatic Habitats

Environments where protists are commonly found, including freshwater and marine ecosystems.

Decomposers

Protists that break down organic matter, cycling nutrients back into ecosystems.

Primary Producers

Protists that produce essential nutrients and serve as food sources for other organisms, contributing significantly to aquatic food webs.

Pathogens

Protists that cause diseases in humans and plants, such as Plasmodium (malaria) and downy mildew.

Endosymbiosis Theory

The theory that eukaryotes evolved from microorganisms that established symbiotic relationships, leading to the origin of key organelles like mitochondria and plastids.

Mitochondria

Organelles believed to have originated from alpha-proteobacteria through endosymbiosis, possessing their own genomes and essential for energy production.

Plastids

Organelles that originated from cyanobacteria, responsible for photosynthesis, found in plant cells and some protists.

Archaeplastida

A group of photosynthetic organisms, including plants, whose plastids originated from cyanobacteria.

Paulinella

A genus of amoeboid protists whose plastids also originated from cyanobacteria.

Key Characteristics of Eukaryotic Cells

Includes features like a nucleus, mitochondria, cytoskeleton, flagella, chromosomes arranged by histones, and the ability to undergo mitosis and sexual reproduction.

Nucleus

The membrane-bound organelle in eukaryotic cells that contains the cell's genetic material.

Cytoskeleton

A network of microtubules and microfilaments in eukaryotic cells that helps maintain cell shape and aids in movement.

Mitosis

The process by which eukaryotic cells divide, resulting in two genetically identical daughter cells.

Sexual Reproduction (Eukaryotic Cells)

A process involving the fusion of gametes, leading to genetic recombination and diversity.