phylogenetics

analogy/homoplasy

characteristic that is similar between organisms by convergent evolution, not due to the same evolutionary path

ancestral

the version of the character found in older ancestors (”older” version)

basal taxon

branch on a phylogenetic tree that has not diverged significantly from the root ancestor

binomial nomenclature

system of two-part scientific names for an organism, which includes genus and species names

branch point

node on a phylogenetic tree where a single lineage splits into distinct new ones

character

attributes that potentially allow its differentiation or potential differentiation from others

character state

the different conditions of a character

derived

the version found in more recent ancestors/descendants (“newer” version)

genus

division of family in the taxonomic classification system; the first part of the binomial scientific name

homology

similarity in characteristics resulting from a shared ancestry

horizontal gene transfer (HGT)

transfer of genes between unrelated species

Carl Linnaeus

taxonomist who first developed a hierarchical model for naming species

maximum parsimony

applying the simplest, most obvious way with the least number of steps

monophyletic group/clade

organisms that share a single ancestor

most recent common ancestor (MCRA)

youngest extinct common ancestor for a particular group of taxa

phylogenetic tree

diagram that reflects the evolutionary relationships among organisms or groups of organisms

phylogeny

evolutionary history and relationship of an organism or group of organisms

polytomy

branch on a phylogenetic tree with more than two groups or taxa

root

single ancestral lineage on a phylogenetic tree to which all organisms represented in the diagram relate

shared ancestral character

when an ancestral character state is shared by two or more taxa in a phylogeny. these taxa may or may not form a monophyletic group

shared derived character

when a derived character state is shared by two or more taxa in a phylogeny. these taxa may or may not form a monophyletic group

sister taxa

two lineages that diverged from the same branch point

systematics

field of organizing and classifying organisms based on evolutionary relationships

taxon (plural: taxa)

single level in the taxonomic classification system

taxonomy

science of classifying organisms

antibiotic

biological substance that, in low concentration, is antagonistic to the growth of prokaryotes

Archaea

domain of life; classified as prokaryotes but more closely related to Eukarya than to Bacteria

bacilli

rod-shape of some prokaryotes

bioremediation

use of microbial metabolism to remove pollutants

binary fission

a form of asexual reproduction in which the DNA of a cell uncoils, duplicates, and moves toward opposite ends of a growing cell before that cell splits into two cells

chemoautotroph

metabolism in which energy is derived from chemical bonds and carbon is derived from inorganic carbon

chemoheterotroph

metabolism in which energy is derived from chemical bonds and carbon is derived from organic carbon

cocci

spherical-shape of some prokaryotes

cyanobacteria

type of bacteria; the first organisms to perform "oxygen producing" photosynthesis

decomposer

organism that carries out the decomposition of dead organisms; role is important in nutrient cycling

emerging diseases

disease making an initial appearance in a population or that is increasing in incidence or geographic range

flagella

a hair-like structure protruding from a cell that is typically used for locomotion

Gram stain

stain that binds to peptidoglycan; used to differentiate Bacteria with peptidoglycan on cell wall surface from other types of prokaryotes

histones

types of proteins that play a roll in organizing DNA

horizontal gene transfer

transfer of genes between unrelated species

LUCA

last universal common ancestor of all living things. likely to have been cellular, use the central dogma, generate ATP, and have organic compounds

metagenomics

method used to classify prokayotic diversity that involves collecting a sample from the environment and generating/analyzing genomic (DNA) or functional (RNA) diversity

nitrogen fixation

process by which gaseous nitrogen is transformed, or "fixed" into more readily available forms such as ammonia

pathogenic

disease causing

peptidoglycan

material composed of polysaccharide chains cross-linked to unusual peptides; found predominantly in cell walls of Bacteria

photoautotroph

metabolism in which energy is derived from light and carbon is derived from inorganic carbon

photoheterotroph

metabolism in which energy is derived from light and carbon is derived from organic carbon

prokaryote

a single-celled organism that lacks organelles and does not have nuclei surrounded by a nuclear membrane

spirilli

spiral-shape of some prokaryote

transduction

type of horizontal gene transfer in which a virus picks up and transfers DNA between cells

transformation

type of horizontal gene transfer in which there is uptake of DNA from the environment

alpha-proteobactria

lineage that through the process of endosymbiosis created mitochondria

chloroplasts

cell organelle that carries out photosynthesis; in plants, result of secondary endosymbiosis

cyanobacteria

lineage that first produced energy using oxygenic photosynthesis, which led to increased concentrations of oxygen in the atmosphere. also the type of bacteria engulfed that led to chloroplasts

endosymbiosis

engulfment of one cell within another such that the engulfed cell survives, and both cells benefit; the process responsible for the evolution of mitochondria and chloroplasts in eukaryotes

Lynn Margulis

evolutionary biologist that was the first to formulate the theory of endosymbiosis as the origin of mitochondria and chloroplast organelles

mitochondria

cellular organelles responsible for carrying out cellular respiration, resulting in producing ATP

alveolus

flattened, membrane-bound vesicles packed into a continuous layer supporting the cell plasma membrane, provide support for the cell

apical meristem

undifferentiated cells of land plant roots and shoots that proliferate throughout life

amoeboid motion

movement of a unicellular organism in which a pseudopodia is extended in one direction and the rest of the cell follows; found in Rhizaria and Ameobozoa

bioluminescence

generation and emission of light by an organism

cellulose

carbohydrate component of green algae and plant cell walls

cuticle

watertight sealant on surface of land plants that prevents water loss

ecosystem service

benefits that humans derive, directly or indirectly, from ecosystem functions

fiddlehead

tightly coiled new fronds of ferns

flavonoids

UV absorbing compounds found in land plants that prevent DNA damage

flower

reproductive structure of flowering plants, typically contain both male and female organs

fronds

large "leaves" of ferns

fruit

thickened tissue derived from ovary wall that protects the embryo after fertilization and facilitates seed dispersal

gametophyte

multicellular and haploid, produce gametes by mitosis

guard cells

specialized cells that open/close stoma

heterospory

produces two types of spores

homospory

produces only one type of spore

lignin

complex polymer impermeable to water, adds support to vascular tissue of plants

flavonoids

UV absorbing compounds found in land plants that prevent DNA damage

phycoerythrin

a pigment that exists in red algae, absorbs blue and green wavelengths and reflects red wavelengths

plankton

diverse group of mostly microscopic organisms that drift in marine and freshwater systems and serve as a food source for larger aquatic organisms

pollen

contain male gametophyte, protective coating resistant to desiccation

rhizoids

thin filaments that anchor mosses to the substrate

root

modified plant tissue to provide anchorage and take in water and nutrients

seed

structure containing the embryo, storage tissue, and protective coat

sori

clusters of sporangia on the underside of fern fronds; where spores are produced

sporophyte

multicellular and diploid, produce spores by meiosis

stamen

flower structure that contains the male reproductive organs; produces pollen

test

porous shell of a foram that is built from various organic materials and typically hardened with calcium carbonate

tracheids

secondary cell walls supported by complex polymer lignin, a type of vascular tissue

vascular plant

plant containing a network of cells that conducts water and solutes through the organism

vessel elements

another type of vascular tissue that is wider, with gaps for more efficient water movement

amoeboid motion

movement of a unicellular organism in which a pseudopodia is extended in one direction and the rest of the cell follows; found in Rhizaria and Ameobozoa

chitin

polysaccharide that is a primary component of cell walls in fungi

exoenzyme

enzymes released outside of cells by fungi; break down insoluble compounds such as the cellulose and lignin of dead wood

hyphae

fungal filament composed of one or more cells

mycelium

a mass of hyphae

mycorrhiza

mutualistic association between fungi and vascular plant roots

mycosis

fungal infection in animals

phagocytosis

a form of feeding in which a larger cell surrounds and engulfs food via infolding of the plasma membrane

saprobe

organisms that derive nutrients from decaying organic matter

spores

haploid cells that can undergo mitosis to form multicellular, haploid individuals

bilateral symmetry

the division of the animal through a midsagittal plane, resulting in two superficially mirror images

blastopore

the opening of the central cavity of an embryo in the early stage of development