Maybe maybe maybe Flashcards
why do organisms reproduce sexually?
organisms reproduce sexually because organisms can pass down traits that are more favorable to the environment
allele
alternate form of gene found at gene locus.
genotype
the genetic constitution of an individual organism
phenotype
a set of observable characteristics/traits of an organism
homozygous
having 2 identical alleles of a particular gene
heterozygous
having 2 different versions of the same gene
gene
basic unit of heredity passed from parent to child
sex linkage
traits on x and y chromosome. most are on x chromosome and recessive
incomplete dominance
both alleles partially expressed(white+red=pink)
co-dominance
both alleles are expressed(white+red=white&red)
adaptation
a modification of an organism or its parts that makes it more fit for existence
competition
A (not so friendly) interaction between two/more organisms for resources. ie. water, food, territory.
predation
the preying of one animal on others.
coevolution
coevolution occurs when two or more species reciprocally affect each other’s evolution through the process of natural selection (bees and flowers)
gene pool
Combo of all allele/gene in a population
lamarck’s theory of evolution
theory of acquired characteristics
darwin’s 5 postulates
post 1: there’s variation in indiv. members of a pop.
post. 2: some variations favorable
post. 3: in each gen. some indiv. survive & reproduce successfully
post 4: indiv.s with favorable traits survive long, leave behind offspring (natural selection)
post 5: a pop. changes over time (evolution)
artificial selection
an evolutionary process in which humans consciously select for or against particular features in organisms (i want hot cats)
sources of genetic variability
Mutations, gene flow, genetic drift, crossing over, environmental variance
directional selection
favors one extreme
stablizing selection
favors moderate/intermediate
disruptive selection
favors both extremes
species
a group of living organisms that are of similar individuals that can interbeed (humans, cats)
allopatric speciation
evolution in species due to geographical barrier e.g. cow have barrier. desert one side field other side. desert cow eat cacti. field side eat grass
sympatric speciation
evolution of new species from surviving ancestors in same geographic area. e.g. catholic beetle that come from communist beetle in Alhambra.
importance of membrane organelles
allow cellular processes to be carried out efficiently in isolation from each other
greenhouse effect
When greenhouse gases are trapped in atmosphere
global warming
Increase in average temps on Earth influenced by human activity
mutualism
:):)
commensalism
:):|
parasitism
:):(
primary succession
ecological succession that takes place in enviro that’s recently formed but lacks soil. happens after nuke/volcano/glacier outburst
secondary succession
ecological succession that occurs after already established gets disrupted (fire/logging/disease)
characteristics of populations
distinguishing physical variations(age,gender,ethnicity,risk of certain disease, etc)
growth rate
the rate a pop. increase/decrease
death rate
ratio of deaths in a pop. of a particular area during particular period of time
birth rate
The ratio of births in a population of a particular area or during a particular period of time
exponential growth
the bigger the pop. the faster it grows. grows infinitely with unlimited resources (j shaped curve)
logistic growth
population grows exponentially first but slows as pop. size nears carrying capacity and becomes stable (s shaped curve)
density dependent limiting factors
pop. growth reduced by ltd. resources due to big pop. (disease,comp,predators)
density independent limiting factors
pop. size affected regardless of size e.g. weather/natural disasters
age structure diagrams
diagram that shows distribution by ages of females&males within certain pop. in graphic form
interphase
G1 (growth phase 1), take nutrient. S (synthesis) replicate chromosome, dna synthesis. G2: done grow ready for division
mitosis
division of nucleus, make 2 daughter cell, PMAT
cytokinesis
division of cytoplasm
meiosis
sex cell division. occurs in animal ovaries and testes
meiosis daughter cells
daughter cells haploid gametes, receive one member of each pair of homologous chromosomes
diploid
“double” cell - full set of chromosome pairs. each gene has 2 alleles.
haploid
one chromosome “per pair”. contain half of the diploid #.
fossils
stuff that exhibit evolution of body structures over time
vestigial structures
Structures that have no apparent function and appear to be residual parts from a past ancestor (wisdom teeth, tailbones)
when evolution idea accepted
ideas of evolution not accepted til darwin published On the origin of Species 1859
evolutionary changes
occur from gen. to gen., cause descendants to diff from ancestors, occur at pop. level
evolution
change of allele freq. in a pop.’s gene pool
mutations
rare changes in base seq. of DNA in a gene. source of new alleles
natural selection
survival of the fittest. selection of phenotypes affects genotypes present in the pop.
abiotic factors
not living stuff (climate, water, soil)
biotic factors
living stuff (humans)
reproductive isolation
when member of one pop. not able to mate with member of another pop.
isolating mechanism
stuff that prevent interbreeding/maintain reproductive isolation
premating vs postmating isolation mechanisms
premate prevents mating between species. post maste prevent formation of viable/fertile offspring after mating.
geographical isolation
no mate because of geographical barrier (there is a wall between u and them)
ecological isolation
no mate because of diff habitat (you live in america, they live in japan)
temporal isolation
no mate because diff time of day/seasons (they night owl, you early bird)
behavorial isolation
no mate because different courtship/mating ritual (they do not like your flirting)
mechanical isolation
no mate because physically incompatible (you are 7 foot they are 4 foot)
hybrid inviability
hybrid offspring fail to survive to maturity (baby die in hospital)
hybrid infertility
hybrid is sterile/reduced fertility; no make baby :( (mule or liger)
inheritance
process by which traits of indiv. passed to their offspring
mendel’s rules
one allele dominant over other allele which is recessive (complex/simple dominance)
level of organization ecology
species (humans), pop. (human in nyc), communities (human, dog, cat in nyc), ecosystem (all organism in an area; desert), biome (desert biome), biosphere (earth)
autotroph
Organisms that produce its own food (photosynthesis, chemosynthesis)
heterotroph
Organisms that eat other organisms
predation
one organism captures+feeds on another pop.
symbiosis
relationship between species
population density
measurement of population per unit land area
