bio exam #1

Microevolution

Microevolution

The change inn the gene pool of a population over time

Evolution

The gradual change in a species/gene pool over time

Macroevilution

Evolutionary change above the species level

Speciation

the evolutionary process by which one species splits into two or more new species/origin of new species

The biological species concept

A species is a group of populations whose members can not with members of other species.

morphological species concept

observable physical traits and can be applied to asexual organisms and fossils (cell wall, shape, habitats) (number of legs, mouthparts(insects))

ecological species concept

Ecological niche(the job) two species can be similar in appearance but distinguishable based on what they eat, live, do, and how to interact

phylogenectic species concept

the smallest group of individuals that share a common ancestor

biological species concept

concept emphasizes reproductive isolation, proposed by Ernst Mayer.

Reproductive barriers

Physical, biological, and behavioral barriers that can prevent interbreeding between different species.

Pre-zygotic barriers

Prevent mating or fertilization between species;

post zygotic barriers

operate after hybrid zygotes have formed

habitat isolation (prezygotic)

encounter each other rarely, or not at all

temporal isolation (prezygotic)

breeding at different times/seasons

behavioral isolation (prezygotic)

different courtship rituals

mechanical isolation (prezygotic)

Incompatible reproductive parts, different sexual parts

gametic isolation (prezygotic)

sperm and egg are incompatible

reduced hybrid viability (postzygotic)

When the genes of different species interact and impair hybrid development. (short-lived hybrids)

reduced hybrid fertility (post-zygotic)

Even if hybrids are vigorous, they may be sterile.

EX: Horse + Donkey = Mule

hybrid breakdown (postzygotic)

Hybrid is fertile, but when they breed the next generation is sterile.

orgin of land plants

Bryophytes

3 phyla are small herbaceous (non-woody) plants, nonvascular plants, and seedless (mosses, liverworts, hornworts) no xylem or phloem, instead they have hydroids and leptoids.

Life cycles dominated by gametophyte

gametophytes are larger and longer-living than sporophytes

Mosses

the oldest land plants with stomata,

protonema

Branching, one-celled-thick filaments produced by germinating moss spores, become the gametophyte in moss.

rhizoids

thread-like structures that anchor non-vascular plants to the ground (mosses and liverworts)

hydroids

special water-conducting cells in the center of bryophyte stems

leptoids

food conducting cells in bryophytes

sporophyte

Diploid, or spore-producing, phase of an organism. Makes haploid spores by meiosis.

Linneaus' system of classification

Kingdom, Phylum, Class, Order, Family, Genus, Species

Whitaker 5 Kingdoms

Monera, Protista Fungi, Plantae, animalia

Taxonomy

the ordered division and naming of organisms

phylogenetic tree

diagram showing evolutionary relationships of organisms with a common ancestor;

Archegonia

female gametangia

Antheridia

male gametangia, produce and release sperm

Hornworts

spores release slowly, from top down, stomata,

Marchantiophyta (Hepatophyta)

liverworts

Lignin

substance in vascular plants that makes cell walls rigid

Xylem

Nonliving vascular tissue that carries water and dissolved minerals from the roots of a plant to its leaves, strengthen by Lignin(increased height)

Pholem

the vascular tissue in plants that conducts sugars and other metabolic products downward from the leaves.

micrphylls

leaves with a single vein

megaphylls

larger leaves with a highly branched vascular system

hetersporous

megaspore becomes female; microspore becomes male

seed plants

Lycophytes

includes club mosses, spike mosses, and quillworts. These lack seeds.

phlyogenetic tree

represents a hypothesis about evolutionary relationships

3 domains of life

Bacteria, Archaea, Eukarya

prokaryotic cell

-small \n - ubiquitous \n -can be free living, symbiotic \n -unicellular may be free living \n -no nucleus or cytoskelton \n -very diverse

External features of prokaryotes, common shapes

- cocci- spherical shaped \n -bacilli- rod-shaped \n -spirilla- spiral and rigid cells

External features of prokaryotes

cell wall \n -imparts shape \n -peptidoglycann found in bacteria \n - gram positive gram negative

Cell walls of fungi are made of

chitin

Gram-positive bacteria

Bacteria that have a thick peptido glycan cell wall, and no outer membrane. They stain very darkly (purple) in Gram stain.

Gram-negative bacteria

Bacteria that have a thin peptidoglycan cell wall covered by an outer plasma membrane. They stain very lightly (pink) in Gram stain. Gram-negative bacteria are typically more resistant to antibiotics than Gram-positive bacteria.

Lipopolysaccharide

component of the gram-negative cell wall

fimbirae

used to attach to surfaces

capsule

protection and attachment

Staphylococcus

cluster of cocci

Streptococci

bacteria that form a chain

motility

flagella

taxis

basic behavioral movement towards or away something

Bacterial Reproduction(prokaryotes)

(asexual reproduction) binary fission

bacterial genetic recombination(prokaryotes)

transformation, conjugation, transduction

transformation

takes foreign DNA from the environment

transduction

movement of DNA between bacteria by bacteria phages

Bacteria phage

A virus that infects bacteria

Conjugation

bacteria exchange DNA by way of sex pili

Endospore

A thick-walled protective spore that forms inside a bacterial cell and resists harsh conditions.

akanet

the resting state of some cyan bacteria

obligate anaerobes

organisms that cannot live where molecular oxygen is present

obligate aerobes

require oxygen

facultative anaerobes

can live with or without oxygen

nitrogen fixation

Process of converting nitrogen gas into ammonia, transforming into a form plants can use

Ammonification

conversion of N2 into ammonium(NH4+)

Nitrification

Nitrifying bacteria convert ammonium into nitrite and then into nitrate.

Denitrification

process by which bacteria convert nitrates into nitrogen gas

heterocysts

nitrogen-fixing cells

Bioflims

microbes attach to solid surfaces

Domain Bacteria

Proteobacteria,

Proteobacteria, \n Chlamydias \n Spirochetes \n Cyanobacteria \n Gram-positive bacteria

Chlamydias

-only intracellular parasites, gram-negative \n -lack of peptidoglycan \n - can become blind, STD

Spirochetes

Gram-negative, chemoheterotrophs, free-living & Parasitic

Cyanobacteria

Photoautotrophs, free-living and colonial heterocysts used to fix N2, no flagella (Anaebena)

Spirochetes

Gram-negative, chemoheterotrophs, free-living & Parasitic

phylum moniophyta

ferns, horsetails and whisk ferns

Horsetails

moist places, homosporous (one type of spore), 15 species, slicia cell wall

Whisk Ferns

scale-like outgrowths on the stem, homosporous, dichotomous branching

Seed Plants

Dominant producers

adaptations of seed plants

hetersporous, ovules, pollen, reduced gameophytes

advantage of reduced seed places

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microspores

develop pollen grains

pollenation

eliminates the need for the film of water

Gymnosperms

pines, produce seeds in cones

cycads

resemble palm trees, grow today only in certain tropical and subtropical regions, bare naked seeds on sporophylls, large cones, flagellated sperm

Gingko Trees

fruit sold, fan-shaped leaves, air pollution, flagellated sperm, no morphological changes in 18 years

Phylum Gnetophyta

Ephedra, Gnetum, Welwitschia

welwitschia

2 leaves, deep tap root

ephedra

A substance derived from a shrub like plant used as a stimulant to boost energy and weight loss

Phylum Coniferophyta

conifers (pines, firs, spruces, bald cypress; Pinus), largest gymnosperm

Flowers consist of four floral organs:

carpels, stamens, petals, and sepals