Biology: Biodiversity, Taxonomy, and Virus Structures

biodiversity

The variety of life on Earth, including genetic, species, and ecological diversity.

species richness

The number of different species in an ecosystem.

species evenness

How evenly individuals are distributed among species.

ecological diversity

Variety of ecosystems in a region.

genetic diversity

Variation of genes within a species.

robust

Strong and resistant to change/disturbance.

invasive species

A non-native species that spreads and harms ecosystems.

binomial nomenclature

The 2-part scientific naming system (Genus species).

taxonomy

The science of classifying organisms.

taxonomist

A scientist who classifies and names species.

taxa

Levels of classification (Domain, Kingdom, Phylum, etc.).

anatomy

Structure.

physiology

Function.

phylogenetic tree

A diagram showing evolutionary relationships.

dichotomous key

Identifying organisms using paired yes/no traits.

cladogram

A diagram that shows evolutionary relationships using derived traits.

ingroup

The group of organisms being studied.

outgroup

A group outside the ingroup, used for comparison.

derived characteristic

A trait unique to a particular evolutionary group.

prokaryote

A cell without a nucleus (Bacteria, Archaea).

eukaryote

A cell with a nucleus (plants, animals, fungi, protists).

Domain Bacteria

Prokaryotes with peptidoglycan in their cell walls.

Domain Archaea

Prokaryotes that live in extreme environments.

Domain Eukarya

All organisms with eukaryotic cells.

viruses

No—they lack cells, can't reproduce without a host, and don't metabolize.

capsid

The protein coat of a virus.

lytic cycle

Virus replicates immediately and bursts the host cell.

lysogenic cycle

Viral DNA integrates into host genome and can stay dormant.

lysis

The breaking open of a host cell.

host cell

The cell a virus infects and uses to reproduce.

pathogen

A disease-causing agent.

antigen

A molecule that triggers an immune response.

antibody

A protein that binds to antigens to neutralize pathogens.

immune system

The body's defense system against pathogens.

bacteriophage

A virus that infects bacteria.

coronavirus

An RNA virus with spike proteins (e.g., SARS-CoV-2).

vaccines

They expose the immune system to antigens, triggering antibody and memory cell production.