IB BIO Y1U2

Lamarks Theory of aquired traits

traits develop throuhout life as a response to environmental factors

Darwins theory of natural selection

indv. with variations that increased fitness would pass traits down to next gen

fitness

measure of reproductive success, ability to survive and reproduce

adaptation

a variation that helps and org. survive, overtime there will be a higher % of favorable traits in a pop

structural adaptation

variation in body of org (color size pattern )

behavioral adpatation

variation in instincts

Physiological adaptation

variation in metabolic processes

selective pressure

a pressure that chooses which traits are favorable for survival

sexual selection

choosing features based on attractivness to mates

Gene pool

all the genes in a population

alleles

different versions of same gene (ex. hair color)

directional selection

one extreeme favored (example peppered moths)

stabalizing selecting

middle favored over extreemes (ex: human baby weight)

disruptive selection

both extreemes favored over middle (ex: oyster shell color)

endlers guppies

guppies were placed in an area with predators, over generations guppies turn dull to camoflauge

In area without predators, guppies are bright to find a mate

sickle cell disease and trait

mutation of hemoglobin, red blood cells are curved

trait: one sickle cell chromosome, one non (Aa)

Heterozygote advantege of sickle cell

Carriers for sickle cell are protected against malaria, but don;t have the disease itself

natural selection

variations that increase fitness are passed on

gene flow

genetic migration, organisms move to a new area

genetic drift

change in gene freq due to random chance (ex. forest fire)

homologous structure

similar structure/blueprint, differnt fuction

ex. pentadactyl limb present in both humans and whales, used differently (fin vs arm)

analogous structures

similar functions (bc environment), but not structurally related

ex. insect and bird wings

vistigal structure

structures that have lost their org. function, but persist because they are coded in DNA

ex: wisdom teeth, persistence of leg bones in whales

COnvergent evolution

unrelated species develop similar structures and functions due to shared environ

divergent evolution

similar species diverge and evolve separately because of enviorn differences

adaptive radiation

rapid diversification of a species from its ancestral species due to enviornmental challenges.

speciation

process of creating a new species by dividing an old one

law of superimposition (fossil record)

oldest fossils are at the bottom

allopathic speciation

speciation that takes place due to different locations

sympathic speciation

speciation occurs in same location

prezygotic barrier

obstacle to mating or fertilization

geographic isolation

prezygotic barrier

• physical barrier prevents species from interbreeding

• ex congo river

Bahvioral isolation

• prezygotic barrier

• unique mating patterns isolate species

• ex mating dances

temporal isolation

• prezygotic barrier

• species breed at different times of year

ecological isolation

species occupy different habitats that dont interact (prezyg barrier)

mechanical isolation

prezyg barrier

morphological differences prevent mating

postzygotic barrier

prevents offspring from being viable/fertile

reduced hybrid viability

postzygotic barrier

hybrids fail to properly develop (health probs)

reduced hybrid fertility

hybrids are sterile (postzyg. barrier)

hybrid breakdown

post zyg barrier

1st gen of hybrid is fertile, the rest are not

gradualism

slow rate of speciation

big change culmunates from many small changes

punctured equalibrium

stable for a long period of time before undergoing an abrupt change (speciation)

polypoloidy

more than 2 copies of each chromosome

error in meisois

autopolyploidy

self fertilization

allopolyploidy

chromosome number doubles because of hybridization

impact of polyploidy

polyploid offspring cant reproduce with parent pop

knotweeds

speciated into new species due to allopolyploidy

Linneaus

classified species based off of appearance

morphological species concept

classification of orgs into species based on appearance

weaknesses: sexual dimorphism, species can look similar

biological species concept

if members of 2 dif species interbreed, the offspring will be unfertile and unviable

weaknesses: asexually reproducing organisms

Single Nucleotide polymorphism (SNP’s)

replacement of one single nucleotide with another, creates variation within a species

chromosome number

haploid- 1 copy

diplpoid 2 copies

humans diploid number - 46

chimp diploid number - 48

formation of chromosome 2 in humans

chromosome 2 in humans was formed by the fusion of chimp chromosomes 12 and 13 (smaller)

autosomes

non sex chromosomes (1-22)

homologous

karyotyping

comparing size/shape/color of chromosomes

sex chromosomes

23rd in humans

XX- female

XY -male

anologous

aneuploidy

abnormal number of chromosomes

Binomial nomenclature

• genus (first letter capitalized)

• special epithet (unique for each species) (lowercase)

• Whole thing italisized

order of taxons from broadest to most specific

Domain → Kingdom → Phylum → Class → Order → family → genus → Species

Dear King Phillip Came Over For Good Soup

autotroph

org makes its own organic compounds from inorganic molecules

heterotroph

org can not make its own complex organic compounds, must get from nutriton

eubacteria kingdom

• unicellular prokaryotes

• cell wall of peptidoglycan

• asexually reproducing (Bacterial congigation)

Archaebacteria kingdom

• Singlecelled prokaryotes

• Asexual reproduction

• Cell wall made of non peptidoglycan

• extreemophiles

animilia kingdom

• multicellular eukaryotes

• both sexual and asexual reproduction

• heterotrophic with internal digestion

• Ex: humans

Plantae Kingdom

• Multicellular eukaryotes

• cell wall of cellulose

• mostly sexual but some asexual reproduction

Fungi Kingdom

Eukaryotic

mostly multicellular but some unicellular

cell wall of chitin

heterotrophic with external digestion

protista

eukaryotes that dont fall within other categories

can be animal like, plant like, or fungi like