Honors Biology Jen Davis final

what is meiosis?

the process of cell division in sex cells

what is a homologous chromosome?

they are autosomes, you receive on for each set from each parent, and they will pair based on their sizes, shapes, and what trait is on the gene

what is a diploid cell?

cells that have 2 complete homologous chromosomes

what is a haploid cell?

cells that only have one chromosome for each set, occurs in sperm/egg cells

when does a diploid cell occur?

during fertilization when a zygote is made

what happens in prophase 1?

chromosomes coil up and find their homologous pair, and crossing over occurs

what is crossing over?

chromosomes switch part of their dna, occurs in prophase 1

what is heredity?

passing of traits from generation to generation

who is gregor mendel?

father of genetics, experimented with pea plants

what is a gene?

a selection of DNA that provides instructions for a character, ex: hitchhikers thumb

what is an allele?

different forms of a gene

what is a locus?

the location of the gene on a chromosome

what does homozygous mean?

alike genetic pairs called purebred. ex: HH or hh

what does heterozygous mean?

one of each allele version. ex: Hh

what is a genotype?

all possible allele combinations of the offspring produced

what is a phenotype?

physical characteristics of each genotype

what is the principle of segregation?

each individual has 2 alleles for a gene

what is the law of independent assortment?

when genes separate and are placed within the gametes, distribution is random, can’t predict with 100% accuracy

what is a filial?

level related organisms within a family

probability:

# of favorable options

__________________

# of total options

what is incomplete dominance?

the allele versions are of the same intensity, so in heterozygotes their phenotype appears to be a mix of the 2 alleles ex: flower color

what is co-dominant/multiple allele?

trait that has more than 2 allele options, if an allele is dominant, it will still make a recessive, but 2 dominant versions can’t mask or mix with each other, both are expressed ex: blood type

what is an x-linked trait?

traits that are found only on the “X” chromosome ex: colorblindness

what is a dihybrid cross?

cross 2 unrelated traits in the same punnett square

what is a pedigree?

form of family tree that tracks a trait though generations. squares represent males and circles represent females

what is an x-linked pedigree?

are the majority of males effected, and if mom has it son has to have it

what is an autosomal pedigree?

a lot of females effected

what are fossils?

relics or impressions of organisms from the past

what is a homologous structure?

same structure, different function

what is comparative anatomy?

structural similarities link related species

what is a vestigial structure?

structures that have a major function in one organism, but less in another ex: whale limbs and ostrich wings

what is an analogous structure?

structures that have the same function in organisms but are not built the same way ex: birds and insects both fly

what is molecular biology?

the closer the dna sequences, the closer related

what is biogeography?

the geographical distribution of species

how old is the earth?

4.6 billion years old

what era are we in right now?

cenozoic

what is microevolution?

changes within a species over dozens or hundreds of generations

what were darwins points?

descent with modification, traits are inherited from parents, all species are capable of reproducing more offspring then their environment can support

what is natural selection?

individuals with inherited traits that are best suited for the environment are more likely to survive and reproduce

what is a gene pool?

all the alleles in all the reproducing individuals that make up a population

what is the founder effect?

few individuals colonize a new habitat

what is gene flow?

exchanging genes with another population, fertile individual can migrate between populations and increase the alleles that can be used in each populations gene pool

what is genetic drift?

change in the gene pool due to chance, effects smaller populations

what is a population bottleneck?

the population is drastically reduced quickly which also reduces the gene pool

what is a mutation?

direct conversion of 1 allele to another

what is artificial selection?

when humans determine the characteristics that survive and reproduce

what is macroevolution?

more dramatic biological changes ex: origin of a different species

what is a species?

a population that can breed with one another and produce fertile offspring

what is allopatric speciation?

speciation due to a physical barrier

what is sympatric speciation?

speciation in the same area due to another type of barrier

what is prezygotic speciation?

before the zygote is formed

what is geographic isolation?

lives in different areas, separated by water, mountains, etc

what is behavioral isolation?

mating rituals are different

what is temporal isolation?

timing of matings becomes different

what is ecological isolation?

different habitats

what is mechanical isolation?

reproductive parts are not compatible, in plants

what is gametic isolation?

the gametes aren’t chemically compatible

what is hybrid inviability?

egg and sperm fuse, but offspring fail to continue to develop. or they die almost immediately

what is hybrid sterility?

offspring is born but cannot reproduce, example mules

what is hybrid breakdown?

offspring can reproduce, but their offspring gets outcompeted

what is gradualism?

fossil record show how species have adapted with very small changes over a long period of time

what is punctuated equilibrium?

species often evolve in spurts of relatively rapid change, followed by longer periods of no change

what is phylogeny?

tracing of evolutionary history of organisms and determining their relationships

what is taxonomy?

the identification and classification of species

what is a vertebrate?

animals with backbones

what is the order from domain to species

domain, kingdom, phylum, class, order, family, genus, species

DEAR KING PHILLIP CAME OVER FOR GINGER SNAPS

what is convergent evolution?

unrelated organisms can show similar adaptations

what is a biotic factor?

all living things in an environment

what is an abiotic factor?

all the non-living things in an environment

what is a keystone species?

species that has an unusually large effect on its ecosystem

what is population density?

the number of individuals in an area

what are limiting factors?

things that can effect population growth, ex natality, growth rates, density, mortality, sex ratios, age distribution, and spatial distribution

what are density-dependent factors?

a factor that limits a population more as the population increases

what are density-independent factors?

limits growth of population but it is unrelated to the population density ex: storms, draughts

what is exponential growth?

growth under ideal conditions will result in enormous amount of individuals

what is logistic growth?

at first grows normally, but slows down as competition and other factors limit reproduction

what is a carrying capacity?

the number of organisms in a population that the environment can maintain without an increase or decrease

what is a boom and bust relationship?

some populations can grow or decrease in relation to other populations

what is dispersion?

the relative distribution or arrangement of its individuals within a given amount of space

what is dispersal?

movement from densely populated areas to new areas

what is a habitat?

physical environment where a species lives

what is a niche?

particular combination of resources that a species is adapted to

what is a dominant species?

a species that is the most abundant in a community

what is a trophic cascade?

triggered by the addition or removal of top predators

what is a foundation species?

species that cause physical changes in the environment that effect others

what are autotrophs?

producers, make their own food

what are heterotrophs?

consumers and decomposers

what is a herbivore?

primary consumer, eats only plants

what is a carnivore?

secondary consumer, eats herbivores and other animals

what is an omnivore?

eat both plants and animals

what is a detritivore?

they eat plant and animal remains

what is a decomposer?

they consume organic wastes and dead organisms

what is a specialist?

consumer that primarily eats one specific organism

what is a generalist?

eat anything

what is the 10% rule?

each level of the food pyramid receives 10% of the energy from the level below it

what is symbiosis?

relationships in which species live together

what is predation?

predator and prey relationship

what is interspecific competition?

competition between 2 species

what is competitive exclusion?

one species succeeding over another when the growth of both species is limited by the same resource

what is mutualism?

both organisms benefit from the symbiotic relationship