BIO 2 Final exam

convergent evolution

when different species evolve similarly becuase they occupy the same environment

(found the same solutions to similar problems)

homology

similarities within different species that are either anatomical, developmental, or molecular

anatomical homology

similar structures derived from a common ancestor

developmental homology

animals in their adult stages that appear very different but had many similarities during their embyronic stages

molecular homology

species with similar DNA and cells in the molecular level

conditions for hardy weignburg equilibrium

no new mutations

no natural selection

random mating

no migration occurs

population is so large that allele frequencies don’t change due to random sampling error

(not met in real conditions as changes occur)

genetic drift

changes in allele frequencies due to random chance

bottleneck effect

population is reduced dramatically and rebuilds without some of the alleles from the gene pool

founder effect

small group of individuals separates from a larger population and establish a new colony

biological species

delineating species based on their ability to interbreed and exchange genes (cannot be applied to extinct or asexual species)

morphological species

delineating species based on their appearance and physical characteristics (continuous variations in many traits and dimorphisms within species)

ecological species

delineating species based on how members of the species interact with their environment (continuous, so it offers no obvious natural cutoff points)

prezygotic barriers

prevents a zygote from forming

postzygotic barriers

prevents the development of a zygote

types of prezygotic barriers

habitat, temporal, behavioral, mechanical, and gametic isolation

types of postzygotic barriers

reduced hybrid viability, fertility, and hybrid breakdown

reproductive isolation

prevents gene flow between groups and allows them to evolve independently

habitat isolation

species live in different places

temporal isolation

species are unable to reproduce because the breed at different times so their gametes never overlap

behavioral isolation

different courtships prevent mate recognition

mechanical isolation

physical differences in reproductive structures that prevent mating

gametic isolation

sperm can’t reach or fertilize eggs of another species

reduced hybrid viability

hybrids die early or are very weak

reduced hybrid fertility

hybrids are healthy but sterile

hybrid breakdown

first-gen hybrids are fertile, but later generations are weak or sterile

sympatric speciation

speciation that occurs in the same habitat

allopatric speciation

geographic isolation prevents gene flow between two or more populations and over time, differences in DNA build up and they become separate species

prokaryotic to eukaroytic

nucleotides and amino acids

nucleotides and amino acids polymerized to DNA, RNA, and proteins

polymers became enclosed in membranes

polymers enclosed in membranes aquired cellular properties

extraterrestrial hypothesis

meteorites brought organic carbon to earth that included amino acids and nucleic acid bases

deep-sea vent hypothesis

biologically important molecules were formed in the deep-sea vents (temperature gradient between extremely hot vent water and cold ocean water)

earth’s age

4.6 billion years old

prokaryotes age

3.5-4 billion years old

eukaryote age

2 billion years for single celled and 1 billion for multicellular

first living cells

evolved in the ocean

parsimony

ppreferred hypothesis is the one that is the simplest for all the characters and their states

domain archaea

more closely related to eukarya and are considered extremophiles

extremophiles

known for their ability to inhabit extreme conditions (salty or hot environments)

bacteria

extremely diverse and form many symbiotic relationships with eukaryotic

cyanobacteria

only photosynthetic bacteria that generate oxygen as a product of photosynthesis (essential for nitrogen fixing)

decomposers

decompose dead materials and recycle its nutrients into the environment

producers

synthesize organic compounds used by other organisms as food

nitrogen fixers

process in which atmospheric N2 becomes biologically usable (cyanobacteria is an example)

pathogens

parasitic microbe causes disease symptoms

syntrophy

some bacteria live together and supply each other with essential nutrients

consortia

larger community of nutrient exchangers

photoautotroph

uses light as its energy source and CO2 as its carbon source

chemoautotroph

uses inorganic compounds as an energy sources and CO2 as a carbon source

photoheterotroph

uses light as an energy source and organic compounds as its carbon source

chemoheterotroph

uses organic compounds for both a light and carbon source

protists

eukaryotes that aren’t classified as plants or animals

protist characteristics

eukaryotic, can reproduce asexually, live in moist habitats

SAR clade

straminopiles, alveolates, rhizarians

archaeplastida

kingdom plantae evolved from green algal ancestors (green, red, and charophyte algae)

unikonta

amoebozoans, opithokonts (including animals and fungi)