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216 Cards in this Set

  • Front
  • Back
study of interactions among organisms and between organisms and their environment
part of Earth in which life exists including land, water, and air or the atmosphere
a group of similar organisms that can breed together
a group of individuals of the same species that live in the same area
assemblage of different populations that live together in a defined area
oollection of al lthe organisms that live in a particular place along with their nonliving environment
group of ecosystems that have the same climate and dominant communities
an organism that captures energy from sunlight or chemicals and uses it to produce its own food (also called a producer)
the process by which plants and some other organisms use light energy to convert water and carbon dioxide into oxygen and carbohydrates
the process by which some organisms, such as certain bacteria, use chemical energy to produce carbohdyrates
organism that obtains energy from the food it consumes (consumer)
organism that obtains energy by eating plants
organism that obtains energy by eatinging animals
organism that obtains energy by eatin both plants and animals
organisms that feeds on plant and animal remains and other dead matter
organism that breaks down and obtains energy from dead organic matter
food chain
series of steps in an ecosystem in which organisms transfer energy by eating and being eaten
trophic level
step in a food chain or food web
ecological pyramid
diagram that shows the relative amounts of energy or matter within each tropic level in a food chain
food web
network of complex interactions formed by the feeding relationships among the various organisms in an ecosystem
total amount of living tissues within a given trophic level
biogeochemical cycle
process in which elements,chemical compounds, and other forms of matter are passed from one organism to another and from one part of the biosphere to another
process by which water changes form a liquid to an atmospheric gas
loss of water from a plant through its leaves
chemical substance that an organism requires to live
nitrogen fixation
process of converting nitrogen gas into ammonia
proces of converting nitrates into nitrogen gas
primary productivity
rate at which organic matter is created by producers in an ecosystem
algal bloom
an immediate increase in the amount of algae and other producers that results from a large input of a limiting nutrient
biotic factors
biological influences on organisms within an ecosystem
abiotic factors
physical or nonliving factors that shape ecosystem
the area where an organism lives (abiotic + biotic factors)
full range of physical and biological conditions in which an organism lives and the way in which the organism uses those conditions
any necessity of life, such as water, nutrients, light, food, or space
competitive exclusion principle
states that no two species can occupy the same niche in the same habitat at the same time
an interaction in which one organism captures and feeds on another organism
any relationship in which two species live closely together
both species benefit
one member of the association benefits and the other is neither helped nor harmed
one organism lives on or inside another organism and harms it
ecological succession
series of changes that occur in a community over time
primary succession
(on land) succession that occurs on surfaces where no soil exists -- usually occurs after a volcano or a glacier melts
pioneer species
first species to populate the area
symbiosis of fungus and an alga & and can grow on bare rock (mutualism)
climax community
the stable ecosystem that develops due to succession
seconday succession
when a disturbance of some kind changes an existing community without removing the soil
complex of terrestrial communities that coversa a large area, has certain soil and climate ocnditions, has certain plants and animals, and is identified by certian abiotic factors
ability to survive and reproduce under certain conditions
a climate in a small area that differs from the climate around it
tropical rain forest
most bio diverse, nutrient poor soil, wet/hot
tropical dry forest
deciduous trees, warm, rich soil
tropical savannah
shrubs, small trees, warm temp. , frequent fires
extreme temperatures, little precip, rich soil in minerals not in organic matter
temperatre grassland
prairies, plains, ferile soil
temperate woodland/shrubland
hot dry summers/ cool moist winters
temperate forest (decidious)
deciduous + coniferous trees, humus, year round rain
formed by decaying leaves and organic matter
northwestern coniferous forest
flowering plants, acidic soil
boreal forest
bitter cold winters/ mild summers
permafrost (layer of solid water & ice) short summers, freezing temps, little recip.
ecosystem where water covers the soil for part or most of the year
wetlands formed where rivers meet the sea
tiny pieces of organic material that provide food for organisms at the base of the stuary's food web
photic zone
well lit upper layer of the ocean-- depth of 200 m
aphotic zone
permanently dark layer of the ocean below the photic zone-- deeper than 200 m
ocean divided into zones based on the depth and distance form the shore
intertidal zone, coastal ocean, open ocean, benthic zone
coastal ocean
extrends from the low-tide mark to the outer edge of the continental shelf, realtiavely shallow border that surrounds the continents
kelp forests
community named for its dominant organism = kelp, a giant brown algae
Benthic zone
the ocean floor that contains organisms that live attached to or near the bottom
organisms that live attached to or near the ocean floor
coral reefs
named for the coral animals whose hard, calcium carbonate skeletons make up their primary structure
population density
number of individuals per unit of area
momvemnt of individuals into an area occupied by an existing population
movement of individuals out of an area
exponential growth
growth pattern in which the individuals in a population reproduce at a constant rate
logistic growth
growht pattern in which a population's grwoth rate slows or stops follow a period of exponential growth
carrying capacity
largest number of individuals of a population that a given environment can support
limiting factor
factor that causes the growth of a population to decrease
density-dependent limiting factor
limitng factor that depends on population size
preador-prey relationship
mechanism of population control in which a population is regulated by predation
density-independent limiting factor
limiting factor that affects all populations in similar ways, regardless of population size
ex. of density- dependent limiting factors
predation, paraisitism, disease, and competition
ex. of density-independent limiting factors
unusual weather, natural disasters, seasonal cycles, and human activity
three important characteristics of population:
geographic distribution, density, and grwoth rate
three factors that can affect population size:
number of births, number of deaths, and number of individuals that enter or leave the population
things that cause population to change:
birth and death, emigration, and immigration
populations grow when:
birthrate is higher than deathrate & immiration is higher than emigration
population says the same when
birthrate equals deathrate & emmigration equals immigration
populations can shrink when
death rate is great than birthrate & emmigration rate is higheer than immigration rate
population growth slows when:
death rate increases, birthrate decreases, or both at the same time
nucleotides (3 parts)
monomers that make up DNA
each nucleotide is made up of three parts:
a phosphate group, deoxyribose (5 carbon sugar) & a nitrogenous base
The four nitrogenous bases are:
adenine <--> thyamine
guanine <--> cytosine
adenine & guanine
thaymine & cytosine
Erwin Chargaff:
showed that the percentages of Cytosine and Guanine are equal as well as Thyamine and adenine
Rosalind Franklin
studied DNA using X-Ray diffraction and it showed that the DNA is twisted aroud "double helix"
James Watson * Francis Crick
made a 3d model of the double helix & discovered that hydrogen bonds hold the bases together
= watson produced "the Double Helix"
= observed that DNA is replicated and the H bonds allow it to replicate quickly
base pairing
principal that bonds in DNA can form only between adenine and thyamine and between guanine and cytosine
during DNA relpication what is the purpose of enzymes
enzymes unzip the strand by breaking the hydrogen bonds
DNA polymerase
main enzyme that joins free-floating nucleotides to produce the DNA polymer
DNA replication
DNA molecuels separates into two strands, then produces two new copmlementary strands following the ruyles of base pairing. Each strand of the double helix of DNA serves as a temple or model for the new stand.
DNA and protein tightly packed together
protein molecule around which DNA is tightly coiled in chromatin
super coiled to form chromosomes
job: to fold enormous lengths of DNA into cell's nucleus
= nucleosomes are composed of DNA wound around histones
sequence of DNA that codes for a protein and thus deterines a trait
messenger RNA
RNA molecule that carries copies of instructions for the assembly of amino acids into proteins from DNA to the rest of the cell
ribosomal RNA
type of RNA that makes up the major part of Ribosomes
transfer RNA
type of RNA molecule that transfers amino acids to ribosomes during protein synthesis
the process in which part of the nucleotide sequence of DNA is copied
RNA polymerase
enzyme similar to DNA polymerase that binds to DNA and separates the DNA strands during transcription
region of DNA that indicates to an enzyme where to bind to make RNA
intervening sequence of DNA; does not code for a protein; gets edited out before they become functional
expressed sequence of DNA; codes for a protein
three-nucoleotide sequence on messenger RNA that codes for a single amino acid
decoding of a mRNA message into a polypeptide chain
group of three bases on a tRNA molecule that are complementary to an mRNA codon
differences between DNA & Rna
- sugar in RNA is ribose instead of deoxyribose
- RNA is generally single-stranded
-RNA contains uracil in place of thymine
-job: to get protein instructsions from DNA and make proteins by building amino acids
changes in the genetic material
point mutations
change in a single DNA base pair
frameshift mutations
many amino acids are changed resulting in a protein that cannot function properly
when part of a chromosome is left out
when part of a chromatid breaks off and attaches to its sister chromatid. you have a duplication of genes on the same chromosomes
part of a chromosome breaks off and is reinserted backwards
part of one chromosome breaks off and is added to a different chromosome
Charles Darwin
traveled around the world and made numerous observations and oclleceted evidence that led him to propose a revolutionary hypothesis about the way life changes over time
- explored the galapagos islands
changes over time, the process by which modern organisms have descended from ancient organisms
scientific theory
a well supported testablie explanation of phenomena that has occurred in the natural world
preservered remains of an ancient organism
darwin/s observation in galapagos islands
very close islands, very diff climate, very diff organisms
natural selection
process by which individuals that are better suited to their environment survive and reproduce most successfully & resulsts in changes in the inherited characteristics of a population
artifical selection
nature provided the variation and humans selected those variations that they found useful
struggle for existence
organisms compete for food, space, and other resources/ nature's version of articiel selection
the ability to survive and reproduice
survival of the fittest
the same as natural selection
any inherited characterstic that increases an organism's chance of survival
descent with modification
each living species has descended from other species with changes over time
evidence of evolution includes:
fossil records, geographic distribution, homologus structures, vestigial organs
fossil records
composed of physical remains of organisms + provides evidence that living things have been evolving for millions of years
geographic distribution
similar animals in different locations were the product of different lines of evolutionary descent
homologous structures
structures that have different forms of development from the same embryonic tissue
similarities in embryology
in early stages, many organisms provide evidence that they shared a common ancestry
vestigial organs
organis with little or no function
scientist who studies fossil
fossil record
provides evidence about athe history of life on Earth. it also shows how diff groups of organisms have changed over time
the species died out
fossils form
dead organism buried in mud or sediment and leaves impression in sedimentary rock. over period of time rock might wear away and expose fossil /
types of fossil
mold- sediment surrounds organism:: hollow
cast- a filled mold :: solid
petrification- minerals replace bone matter & petrify the organism
imprint- footprint/tracking that hardens
amber- hardened sap containing preserved organisms
index fossils/requirements
fossils used to compare the relative age of fossils/easily recognizes, existed for short period, wide geographic range
relative dating
the age of a fossil is determined by comparing its placement with that of fossils in other layers of rock
absolute dating (radioactive dating)
the use of half-lives to determine the age of a sample/ scientists calculate the age of a sample based on the amount of remaining isotopes it contains
half life
the length of time reuired for half of the radioactive atoms in a sample to decay
if they have a fossil they believe is younger than 60,000 years old they will use
carbon 14
if they have a fossil they believe is older than 60,000 years old they will use
potassium 40
how many organisms that once lived on earth are now extinct?
when was earth created
4.6 billion years ago
gases in the formation of the earth
carbon monoxide, hydrogen cyanide, nitrogen, methane
Miller-Urey experiment
suggested how mixtures of the organic compounds necessary for life could have arisen from simpler compounds present on primitive earth
protenoid microspheres
tiny bubbles formed from organic molecules; are not cells but contain characteristics of a cell because they have a selectively permeable membrane
endosymbiotic theory
proposes that eukaryotic cells arose from living communities formed by prokaryotic cells
aerobic bacteria entered ancient anaerobic prokayote and that evolved into
photosynthetic bacteria enetered ancient anaerobic prokaryote and evolved into
microscopic fossils
at first oxygen drove some lif forms into ____
Lynn Margulis
did research on endosymbiotic theory and extracted DNA from primitive and plant fossilized cells and they very closely matched up
Precambrian time
beginning of earth's history/most of earth's history occurred here/anaerobic life forms
paleozoic era: cambrian period
age of the invertebrates/trilobites were most common/most organisms had hard shells
paleozoic era: devonian period
age of fish/introduction to vertebrates/basic amphibian/insects
paleozoic era: carboniferous period
extensive plant growth/evolution of the reptile/many amphibians and trilobites when extinct
mesozoic era: triassic period
age of the reptiles/introduction to dinosaurs/first mamals
mesozoic era: jurassic period
age of the dinosaurs
mesozoic era: cretaceous period
flowering plants/extinction of dinosaurs
cenozoic era
mammals evolved adaptations that allowed them to live in various environments
cenozoic era: tertiary period
marine mammals evolved/ insects and flowering plants flourished/grass eating animals evolved
cenozoic era: quaternary period
-beginning of ice ages
- mammoths roamed the earth
adaptive radiation
single species evolves into several different species that live in different ways (finches)
convergent evolution
unrelated organisms evolve similar characteristics when adapting to similar environments
two species thatinteract over a long period of time change and adjust to one another
large scale evolutionary patterns and processes that occur over long periods of time
puncuated equilibrium:
stable periods interuppted by rapid changes involving many different lines of dsecent
gradual evolution; slow steady in a particular line of descent
hox genes
master control genes; guide development of major body structures in animals;
classifying organisms and assigning them a universally accepted name
Kingdom, phlyum, class, order, family, genus , species
each levil of the classifcation system
evolutionary relationships aong organisms
derived characters
characters that appear in recent parts of lineage but no in its older members
a diagram that shows evolutionary relationships among a group of orgnaisms
more inclusive category than any other / larger than a kingdom/ 3 domains: bacteria, euklarya, archaebacteria
binomial nomenclature
two name system developed by Linnaeus/ first name genus second name species / first name capitalizes
six kingdoms of life
eubacteria, archaebacteria, protista, fungi, plantae, animalia
3 domain system:
archaebacteria, bacteria, eukarya
(domain) bacteria
prokarytoic, cell walls have peptidoglycan, unicellular/ strep, e coli
(DOMAIN) archaebactera
prokaryote; no peptidoglycan/ unicellular/yeast
(domain) eukarya
prostista, fungi, plantae, animalia,; eukaryotic
has a dorsal holllow nerve chord;notochord; pharyngeal puches; tail that extends beyong the anus
two groups of nonvertebrate chordates:
= tunicates (sea squirts) no tail or notochord as an adult
= lancelets/ do not have a true heart/ live on ocean bottoms
basic characteristics of a fish
gils/paired fins/aquatic vertebrates with backbones/ scales
evolution of fishes
first vertebrates to evolve from an invertebrate ancestor
/ evolution of jaws and paired fins were imporatn development
first fishes in devonian period were...
jawless with armored bony plates
strong tissue that protects the bone
structures of cartilage that support the fins
fish are classified into 3 groups
cartilaginous, jawless, bony
jawless fish
lack vertebrae, and have fibers/ lampreys & hagfish
sharks/rays' have a lot of teeth
bony fish
ray-fined or lobe-finned
circulatory system of fish
closed circulation system:: heart pumps blood through body in a single loop from heart to gills to the rest of the body and back to the heart
heart of fish
4 parts within 2 chambers// the atrium and the ventricle
reponse of a fish
well developed nervous system + brain
parts of a fish's brain
olfactory bulb- sense of smell
cerebrum- voluntary activitie
optic lobe- processes eye information
movement of a fish
alternating contracting paired muscles
swim/air bladder
internal, gas-filled organi that adjusts levels of buoyancy
how do fish get rid of nitrogenous wastes
in the form of ammonia through gills or kidneys
urine of freshwater fish
surrounde dby lost of water; urine tend to be diluted
urine of saltwater fish
tend to lose water by osmosis; urine tends to be concentrated
reproduction of fish
oviparous- eggs hatch outside mothers body and food is obtained from yolk
ovoviviparous- result of internal fertilization; egg stay in mothers body; young born alive
viviparous: bears live young; nourished from mother's body