bio unit 4 test review

evolution

charles darwin

• figured out how evolution works

• proposed natural selection

• galapagos islands

modern theory of evolution

• earth is old and is constantly changing

• as the environment changes, evolution happens as species adapt to the new environment

• natural selection is the mechanism that causes species to change

• descent with modification is modern species evolved from earlier species and share a common ancestor

• species that cannot adapt reduce in number and may become extinct

• new traits arise in species from mutations and genetic recombination

descent with modification

modern species evolved from earlier species and share a common ancestor
- next generation of offspring inherit characteristics from parents that fit environment

natural selection

• organisms with best characteristics for survival live longer and produced offspring

• environment ‘chooses’ who lives and dies

steps of natural selection

• overproduction - too many offspring are produced that can possibly survive

• competition - offspring must struggle to survive and reproduce

• variations - members of a species are different from each other due to sexual reproduction, genetic recombinations, and mutations

fossils

remains of traces of dead organisms preserved in rock layers

homologous structures

• similar parts but different function

• show different species are related and have a common ancestor in the distant past

vestigial structures

no longer useful structures

EX: wisdom teeth, tail bone, appendix, goosebumps

population

same species living in the same place at the same time

adaption

group of characteristics that help the organism survive and reproduce

• populations adapt and evolve, not individuals

structure - body part
physiology - internal process
behavior - what organism does

EX:
the long ears (structure) of a rabbit allows it to hear predators (physiology) and run away (behavior)

artificial selection

selective breeding

• humans choose which individuals based on characteristics the organism has

• those traits will be seen in the offspring

EX: dog breeding

gene pool

all the genes and alleles available to a population when they mate and reproduce

changes in gene pool can happen due to:

• natural selection

• genetic drift - random chance

• gene flow - exchange genes with another population

• mutation - new variation

microevolution

• changes in alleles found in the gene pool

• alleles increase or decrease over each generation depending on which traits are helpful

EX:

green bugs do not camouflage as brown bugs, and green bugs are eaten

speciation

the process of forming a new species from an existing species from:

• geographic isolation

• new variations and adaptions

  time apart

• reproductive isolation

species

organisms that mate with each other in nature and produce fertile offspring

macroevolution

speciation - forming a new species

reproductive isolation

organisms cannot mate with each other due to reproductive barriers

EX:

• timing - different species are fertile and have mating seasons at different times

• behavior - different species attract mates in different ways (scent, dance, colors)

• habitat - based on where the species live (top of water vs. bottom)

• genetics - number of chromosomes is different, if mating occurs offspring are not produce/not fertile

geographic isolation

separation of populations due to land or water

• leads to reproductive isolation because individuals of the species no long have contact with each other and may adapt to different habitats

EX:

mountains, deserts, lakes

3 domains

bacteria - prokaryotic (no nucleus)

archaea - prokaryotic (no nucleus + DNA has introns)

eurkarya - eukaryotic (nucleus + DNA has introns)

fitness (survival of the fittest)

a measure of how well a trait helps an organism to survive and reproduce in its environment

• no rule, what is fit in one environment may be unfit in another

explain the evolution with pesticides:

insects evolve resistance to pesticides. when exposed to the pesticides, the insects with genetic resistance to the pesticides survive and reproduce; the ones without the resistance die. the next generation will have more resistant insects

classification

organisms are classified based on their evolutionary relationship

phylogenetic trees

show the evolutionary relationship between living species and extinct species

ecology

study of interactions between organisms and their environment

habitat

where an organism lives

niche

what an organism does, primarily determined by when, where, and how it obtains food

• niche creates competition

competition

the struggle between organisms for the same resource in an ecosystem at the same time

• organisms defend territory for food

cooperation

organisms benefit each other

• organisms shelters another, exchange resources

• co-evolution relationships

abiotic

nonliving parts of an ecosystem

EX:
air, water, sunlight, temperature, soil

biotic

living parts of an ecosystem

EX:
all of the organisms

carrying capacity

the largest population an ecosystem can support

limiting factors

anything that limits the size of a population

could be : sunlight,, water, temperature, climate, food, predators, disease, competition

overpopulation

when a population exceeds the carrying capacity

• results in large number of organisms dying off until a new balance is reached

group behavior

group behavior has evolved because membership in a group can increase the chances of survival individuals and their genetic relatives

biodiversity

the variety of all life on earth

diverse ecosystems

many different species are more stable than those that are not diverse

nutrition

taking in nutrients for various activities including:

• growth

• repair damaged tissues

• synthesis

• cellular respiration

xylem and phloem

tubes that transport water (xylem) and food (phloem) through plant

energy pyramid

shows that energy is lost with each step in a food chain

carbon cycle

during photosynthesis, plants take in n carbon dioxide and release oxygen into the air

during cellular respiration, carbon dioxide is released as waste

during process of decay, decomposers release carbon dioxide, used to make glucose