Biology Lecture Notes: Evolution, Systematics, Viruses, and Prokaryotes (Vocabulary)

Vocabulary flashcards covering key terms from the notes on taxonomy, systematics, phylogeny, viruses, prions, and prokaryotes.

Taxonomy

Science of naming, describing, and classifying organisms.

Systematics

Classification scheme based on evolutionary relationships among organisms.

Cladistics

Study of taxonomic groups formed from an ancestor and all its descendants.

Derived character

A trait that evolved in a lineage and is not present in its most distant ancestors.

Ancestral-characteristic

A trait that the common ancestor had and is shared by its descendants.

Analogous trait

Trait shared by different groups due to convergent evolution, not common ancestry.

Homologous trait

Trait shared by different species because of a shared evolutionary origin.

Phylogenetic tree

Diagram showing evolutionary relationships among organisms.

Binomial nomenclature

Two-part Latin naming system for species (Genus and species).

Genus

First part of the binomial name; capitalized and italicized.

Species

Second part of the binomial name; lowercase and italicized.

Kingdom

One of the highest taxonomic ranks in traditional classification.

Phylum

Taxonomic rank below Kingdom and above Class.

Class

Taxonomic rank below Phylum and above Order.

Order

Taxonomic rank below Class and above Family.

Family

Taxonomic rank below Order and above Genus.

Domain

Highest taxonomic rank above Kingdom; there are three domains.

Archaea

Prokaryotes often in extreme environments with distinctive cell membranes.

Bacteria (Eubacteria)

Prokaryotes; lack most membrane-bound organelles; abundant and diverse.

Virus

Non-cellular infectious agent with nucleic acid (DNA or RNA) inside a protein coat; requires a host to reproduce.

Capsid

Protein coat that encases a virus's genetic material.

Nucleic acid

The genetic material of a virus: DNA or RNA.

Virion

A complete, infectious virus particle outside its host.

Bacteriophage

Virus that infects bacteria.

Lytic cycle

Viral replication cycle that bursts the host cell to release new viruses.

Lysogenic cycle

Viral genome integrates into host DNA and replicates with the host.

Endospore

Tough, dormant form of certain bacteria that survives harsh conditions.

Prion

Infectious agent composed of misfolded protein; lacks nucleic acid.

PrP (prion protein)

Normal protein that can misfold into a prion.

Transmissible spongiform encephalopathies

Group of prion diseases causing brain damage and spongiform degeneration.

BSE (Mad Cow Disease)

A prion disease affecting cows, associated with prion transmission.

Influenza

Enveloped RNA virus with types A, B, and C.

Hantavirus

Single-stranded RNA virus associated with rodents.

Hemorrhagic fever

Severe illnesses (e.g., Ebola) caused by certain viruses with high lethality.

SARS (Severe Acute Respiratory Syndrome)

RNA virus causing severe respiratory illness.

HIV (Human Immunodeficiency Virus)

Retrovirus that attacks the immune system, leading to AIDS.

SIV (Simian Immunodeficiency Virus)

Virus in nonhuman primates related to HIV; believed to be a precursor to HIV in humans.

Conjugation

Horizontal gene transfer in bacteria via direct contact.

Transduction

Gene transfer mediated by a bacteriophage.

Transformation

Uptake of free DNA from the environment by a bacterium.

Binary fission

Asexual reproduction in prokaryotes where one cell divides into two.

Gram-positive

Bacteria with thick peptidoglycan layer; stain purple in Gram stain.

Gram-negative

Bacteria with thin peptidoglycan layer and outer membrane with lipopolysaccharide; stain red.

Peptidoglycan

Sugary-protein complex forming the bacterial cell wall.

Cocci

Spherical-shaped bacteria.

Bacilli

Rod-shaped bacteria.

Spirilla

Spiral-shaped bacteria.

Spirochete

Long, corkscrew-shaped bacteria.

Chlamydia

Gram-negative, intracellular bacteria.

Streptococcus

Gram-positive cocci that grow in chains.

Staphylococcus

Gram-positive cocci that grow in clusters.

Convergent evolution

Evolution of similar traits in unrelated lineages due to similar environments.