Taxonomy, Phylogeny, Viruses, and Bacteria Overview

Taxonomy

Branch of biology identifying and classifying species.

Phylogeny

Study of evolutionary relationships among organisms.

Morphological Species Concept

Species identified by size, shape, and features.

Biological Species Concept

Species defined by mating patterns and offspring viability.

Phylogenetic Species Concept

Species defined by evolutionary relationships and DNA analysis.

Binomial Nomenclature

Two-part naming system for species identification.

Genus

First part of a species' scientific name.

Species

Second part of a species' scientific name.

Hierarchical Classification

Organization of species from general to specific categories.

Taxonomic Categories

Eight nested levels of biological classification.

Domain

Largest taxonomic grouping: Eukarya, Bacteria, Archaea.

Kingdom

Second largest category: Animalia, Plantae, Fungi, Protista.

Phylum

Third level in the taxonomic hierarchy.

Class

Fourth level in the taxonomic hierarchy.

Order

Fifth level in the taxonomic hierarchy.

Family

Sixth level in the taxonomic hierarchy.

Cladogram

Diagram showing evolutionary relationships among species.

Phylogenetic Tree

Branching diagram illustrating evolutionary history.

Anatomical Evidence

Study of structure and form in organisms.

Physiological Evidence

How organisms function, including biochemistry.

Derived Characteristics

New features that arise in evolutionary branches.

Ancestral Characteristics

Original traits present in the oldest ancestors.

Drug Discovery

Process of finding new pharmaceuticals and treatments.

Disease Transmission

Method by which diseases spread between hosts.

Crop Resistance

Ability of crops to withstand pests and diseases.

Dichotomous Key

Tool for identifying organisms through yes/no questions.

Viruses

Infectious agents requiring host cells for replication.

Capsid

Protein shell enclosing a virus's genetic material.

RNA Viruses

Viruses with high mutation rates, e.g., HIV.

DNA Viruses

Stable viruses, often used in vaccines, e.g., Hep B.

Helical Virus

Virus with a spiral-shaped capsid structure.

Polyhedral Virus

Virus with a 20-faced capsid, e.g., pink eye.

Spherical Virus

Enveloped virus with spike proteins, e.g., coronavirus.

Complex Virus

Bacteriophages with a polyhedral head and helical tail.

Lytic Cycle

Virus replicates and destroys host cell immediately.

Lysogenic Cycle

Virus integrates into host DNA, remains dormant.

Provirus

Inactive viral DNA integrated into host genome.

Retroviruses

Viruses converting RNA to DNA using reverse transcriptase.

Prions

Infectious proteins lacking nucleic acids, causing diseases.

Virus Replication

Process where viruses copy genetic material in host.

Attachment Phase

Initial contact of virus with host cell surface.

Injection Phase

Virus injects its genetic material into host cell.

Integration Phase

Viral DNA merges with host cell's DNA.

Contact

Exchange of bodily fluids between organisms.

Vectors

Agents that transmit pathogens between hosts.

Virotherapy

Using viruses to treat bacterial diseases.

Prokaryotes

Cells without a nucleus or membrane-bound organelles.

Peptidoglycan

Polymer forming bacterial cell walls.

Gram Positive

Bacteria with two layers, stains purple.

Gram Negative

Bacteria with three layers, stains light pink.

Autotrophs

Organisms that produce their own food.

Heterotrophs

Organisms that obtain nutrients by consuming others.

Chemotrophs

Organisms using carbon or sulfur compounds for energy.

Aerobic Respiration

Process requiring oxygen for energy production.

Anaerobic Respiration

Process occurring without oxygen for energy production.

Obligate Aerobes

Organisms that must have oxygen to survive.

Obligate Anaerobes

Organisms that cannot survive in oxygen.

Facultative Anaerobes

Organisms that can survive with or without oxygen.

Binary Fission

Asexual reproduction method in bacteria.

Conjugation

Sexual reproduction in bacteria involving genetic exchange.

Bacterial Reproduction

Process of producing new bacterial cells.

Plasmid DNA

Extrachromosomal DNA in bacteria, not genomic.

Pili

Hair-like structures for bacterial genetic exchange.

Endosymbiosis

Theory explaining eukaryotic cell evolution from prokaryotes.

Mitochondria

Cell organelles evolved from engulfed aerobic bacteria.

Chloroplasts

Organelles evolved from engulfed cyanobacteria.

Binary Fission

Asexual reproduction method in prokaryotes and organelles.

Protista

Domain of mostly unicellular eukaryotic organisms.

Heterotrophs

Organisms that consume other organisms for energy.

Ciliates

Protozoans with cilia for movement and feeding.

Paramecium

Ciliate protozoan, has two nuclei, reproduces sexually.

Zoomastigina

Flagellated protozoans, can be free-living or parasitic.

Sporozoa

Parasitic protozoans with sexual and asexual reproduction.

Amoeba

Single-celled organism with pseudopods for feeding.

Cercozoa

Phylum of protists without cell walls, shape-changing.

Fruiting Bodies

Structures that produce spores by meiosis.

Plasmodial Slime Moulds

Multinucleate organisms that feed on decaying matter.

Cellular Slime Moulds

Form multicellular structures from amoeboid cells.

Water Moulds

Fungus-like organisms living on dead organic matter.

Phytoplankton

Unicellular, free-floating aquatic organisms, photosynthetic.

Diatoms

Algae with silica cell walls, reproduce asexually.

Dinoflagellates

Phytoplankton with two flagella, rapid reproduction.

Euglenoids

Photosynthetic or heterotrophic organisms with light detection.

Brown Algae

Largest algae group, forms biodiverse marine ecosystems.

Red Algae

First multicellular organisms, abundant in marine environments.

Green Algae

Diverse freshwater organisms, can cause algal blooms.