Bio1220L: Practical One (copy)

Dichotomous Keys

Organized couplets consisting of mutually exclusive characteristics used to identify organisms.

Bracketed Keys

A type of dichotomous key that uses a series of paired statements to guide identification of species.

Indented Keys

A type of dichotomous key that presents characteristics in a nested format, where each level represents a decision.

Monophyletic Groups

Groups of organisms that descended from the same common ancestor, also called clades.

Polyphyletic Group

A group of organisms descended from different common ancestors.

Paraphyletic Group

A group of organisms that includes a common ancestor but does not include all its descendants.

Homologous traits/synapomorphies

Traits shared between organisms that derive from a common ancestor.

Symplesiomorphies

Traits shared by all organisms within a phylogenetic tree.

Analogous Traits

Traits that arise due to convergent evolution, not from a common ancestor.

Hardy-Weinberg Equilibrium

A model that describes the condition where allele frequencies in a population remain constant over time.

Allelic Frequency

The relative frequency of an allele at a genetic locus in a population.

Genotypic Frequency

The proportion of different genotypes in a population.

Gram Negative Bacteria

Bacteria that stain pink due to low peptidoglycan content in their cell walls.

Gram Positive Bacteria

Bacteria that stain purple due to high peptidoglycan content in their cell walls.

Shannon Index

A measure of species diversity in an ecosystem, taking into account species richness and evenness.

Species Richness

The total number of different species in a given area.

Species Evenness

A measure of how evenly individuals are distributed among the species in a community.

Phenology

The study of the timing of life cycle events in organisms.

p-value

A statistical measure that helps to determine the significance of results.

Protists

Eukaryotic organisms that cannot be classified as animals, plants, or fungi.

Animal-Like Protists

Heterotrophic, usually unicellular protists that feed on other organisms.

Fungus-Like Protists

Heterotrophic protists that decompose organic matter, can be unicellular or multicellular.

Plant-Like Protists

Autotrophic protists that conduct photosynthesis, primarily unicellular.

Euglenids

Unicellular algae that are autotrophic and have one flagellum.

Dinoflagellates

Unicellular marine algae that have two flagella.

Diatoms

Unicellular algae with silica cell walls, forming various shapes.

Brown Algae (Phaeophyta)

Multicellular marine algae, which include kelp and are the largest protists.

Red Algae (Rhodophyta)

Multicellular marine organisms often found at greater depths than other algae.