BIO 112 Exam 1

Prion

A misfolded infectious protein that can cause degenerative brain diseases in animals.

Pandemic

A global outbreak of disease.

Viral Envelope

A protective layer surrounding the capsids of viruses found in animals, derived from host cell membranes.

Lytic Cycle

A bacteriophage replicative cycle that results in the death of the host cell.

Virus

Infectious particles that consist of genes and a protein coat.

Reverse transcriptase

An enzyme used by retroviruses to convert RNA into DNA.

Emerging virus

A virus that suddenly becomes apparent and often spreads quickly.

Lysogenic

A viral cycle that replicates the phage genome without destroying the host.

Host specific

Refers to the limited number of host species a virus can infect based on receptor fits.

Paralogous

Genes that result from gene duplication and can diverge within a species.

Homology

Genetic similarities due to shared ancestry.

Basal Taxon

The oldest organism that diverges early in the history of a group.

Molecular Clock

A gene that mutates at a constant rate to infer the timing of mutations.

Sister Taxa

Groups sharing an immediate ancestor not shared with any other group.

Analogy

Genetic similarities that arise from convergent evolution.

Phylogeny

The evolutionary history of a species or group of species.

Clade

A group of organisms that includes an ancestor and all its descendants.

Monophyletic

A clade that consists of an ancestor and all of its descendants.

Binomial Nomenclature

A method of naming species using two terms: genus and species.

Horizontal Gene Transfer

The transfer of genetic material between organisms that are not parent and offspring.

Maximum Parsimony

The least amount of assumptions required for an observation consistent with the facts.

Gram Stains

A method used to classify bacteria based on their cell wall characteristics.

Peptidoglycan

A structural component of bacterial cell walls.

Resistance (r plasmid)

Plasmids that carry genes for antibiotic resistance.

Binary fission

A method of prokaryotic cell replication resulting in two identical cells.

Slime layer

A poorly organized layer of polysaccharides or proteins surrounding the cell wall.

Capsule

A well-organized slime layer of polysaccharides/proteins surrounding the cell wall.

Nucleoid

The region in prokaryotic cells where DNA is stored.

Activated Transduction

Process where phages carry prokaryotic genes from one host cell to another.

Transformation

The process by which prokaryotic cells take up foreign DNA from their surroundings.

Conjugation

The transfer of DNA between two prokaryotic cells through a pilus.

Photoautotroph

Organisms that obtain energy from light and use CO2 for carbon.

Obligate Aerobes

Organisms that require oxygen for cellular respiration.

Obligate Anaerobes

Organisms that die from oxygen and require anaerobic conditions.

F plasmid

A plasmid that contains the fertility factor required for pili production.

RNA

A type of nucleotide sequence that lacks proofreading capabilities.

Antibiotics

Substances that kill bacteria but do not affect viruses or eukaryotic cells.

Plasmodesmata

Channel proteins in plants that allow for the spread of viral infections.

Self Assemble

The process by which viral particles piece themselves together before release.

Lambda

A temperate phage used widely in biological research.

Vaccine

A harmless derivative of pathogenic microbes that stimulates the immune response.

Retrovirus

A type of RNA virus that uses reverse transcriptase to synthesize DNA from RNA.

rRNA

The RNA type that plays a key role in the structure of ribosomes.

Lipids

Molecules that make up viral envelopes.

Mutation

A process leading to genetic diversity in bacteria due to rapid reproduction.

Extreme halophiles

Archaea that thrive in highly saline environments.