Bacteria, Archaea, Plants, Fungi, and Protists Vocabulary

Vocabulary practice flashcards defining foundational biological concepts from Chapter 15 (Bacteria & Archaea) and Chapter 16 (Plants, Fungi & Protists).

Prokaryote

A single-celled organism in domain Bacteria or Archaea characterized by circular, free-floating DNA, no nucleus, and no membrane-bound organelles.

Eukaryote

An organism in domain Eukarya characterized by cells with a true nucleus enclosed in a nuclear envelope and membrane-bound organelles with specialized functions.

Human Microbiome

The complete collection of microbes living in and on human cells and bodies, consisting of approximately $39\text{ trillion}$ microbial cells.

Binary Fission

A method of asexual reproduction in prokaryotes where a parent cell replicates its DNA and divides into two identical daughter cells within $10\text{--}30\text{ minutes}$.

Stromatolites

Fossilized bacterial secretions found in rocks, such as those formed $3.7\text{ billion years ago}$ in Greenland.

Thermophiles

Extremophilic archaeans that thrive in extremely hot habitats exceeding $100^\circ\text{C}$ ($212^\circ\text{F}$), such as geysers, hot springs, and hydrothermal vents.

Halophiles

Extremophilic archaeans that thrive in environments with extremely high salinity, such as the Great Salt Lake or the Dead Sea.

Bacillus

A rod-shaped bacterium.

Coccus

A sphere-shaped bacterium.

Spirillum

A spiral-shaped bacterium.

Spirochete

A corkscrew-shaped bacterium with spiral threads.

Vibrio

A comma-shaped or curved-rod bacterium.

Pili

Short, hair-like projections on prokaryotic cells used to attach bacteria to surfaces or to other bacteria to form mats.

Flagella

One or more whip-like spinning structures that propel a bacterium through liquid.

Slippery Capsule

A protective coating around the cell wall of some bacteria that helps disease-causing strains evade the host immune system.

Quorum Sensing

A cell-to-cell communication system in microbes that enables bacteria to sense and respond to nearby bacteria based on population density.

Sporulation

The formation of thick-walled dormant structures (spores) that can survive boiling and freezing, occurring in some bacteria but no archaeans.

Cyanobacteria

Aquatic photosynthetic bacteria responsible for evolving oxygenic photosynthesis, raising atmospheric oxygen levels to nearly $10\%$ approximately $2.1\text{ billion years ago}$.

Nitrogen Fixation

The chemical process performed by certain bacteria that takes nitrogen gas from the air and converts it into ammonia.

Dysbiosis

A health condition resulting from an imbalance in the normal human microbiome.

Kingdom Protista

A diverse eukaryotic kingdom defined by exclusion, containing all eukaryotes that are not classified as plants, animals, or fungi.

Protozoans

Non-photosynthetic, motile protists that eat other organisms.

Algae

Photosynthetic protists that may or may not be motile.

Mixotrophs

Nutritional opportunists that can use energy and carbon from multiple sources.

Bryophytes

Simple land plants, including liverworts and mosses, that lack vascular tissue and absorb water directly into their thin bodies via wicking action.

Vascular System

An extensive network of tube-like structures in plants specialized for transporting fluids.

Ferns

The first group of land plants to evolve a vascular system and lignin, allowing them to grow tall.

Lignin

One of the strongest materials in nature that links cellulose fibers in plant cell walls to form a rigid network enabling tall growth.

Gymnosperms

Vascular plants (conifers, cycads, Ginkgo, gnetophytes) that first evolved pollen and naked seeds sitting bare on modified leaves.

Pollen

Microscopic structures containing sperm cells that are dispersed through the air, removing the reliance on water for fertilization.

Angiosperms

Dominant, diverse flowering plants whose ovules are enclosed within an ovary wall that develops into fruit after fertilization.

Ovules

Egg-bearing structures in plants that develop into seeds after fertilization.

Kingdom Fungi

A kingdom of eukaryotic absorptive heterotrophs with cell walls that digest organic matter externally and store surplus energy as glycogen.

Hyphae

A network of fine, colorless, branching hair-like threads that absorb nutrients from the environment in fungi.

Mycelium

The entire bundle or network of hyphae that comprises the main body of a fungus.

Zygomycetes

A taxonomic group of fungi consisting of many species of molds.

Ascomycetes

A diverse group of fungi commonly known as sac fungi, which includes truffles.

Basidiomycetes

A group of fungi commonly known as club fungi, which includes typical mushrooms.

CITES

The Convention on International Trade in Endangered Species of Wild Fauna and Flora, an international treaty of over $175\text{ countries}$ regulating trade in wild plants and animals.