140 terms

EEMB 22 Midterm 1

STUDY
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atom
fundamental building block of all matter
biology
systematic study of life
cell
smallest unit of life
community
all populations of all species in a given area
emergent property
a characteristic of a system that does not appear in any of a system's component parts
ecosystem
a community interacting with its environment
molecule
an asscoaition of tow or more atoms
nature
everything in the universe except what humans have manufactured
organism
individual that consists of one or more cells
population
group of individuals of the same species that live in a given are
consumer
organism that gets energy and carbon by feeding on tissues, wastes, or remains of other organisms
development
multistep process by which the first cell of a new individual becomes a multicelled adult
DNA
deoxyribonucleic acid; molecule that carries herediatary info about traits
energy
the capacity to do work
growth
increases in the number, size, volume of cells in multicelled species
homeostasis
set of processes bu which an orgnaism keeps its internal conditions within tolerable ranges
inheritance
transmission of DNA from parents to offspring
nutrient
substance that na orgnaism needs for growth and survival, but cannot make for itself
producer
orgnaism that makes its own food using energy and simple raw materials from the environment
receptor
molecule or structure that responds to a specific form of stimulation
reproduction
process by which parents produce offspring
animal
multicelled consumer that develops through a series of embryonic stages and moves about during part or all of the life cycle
archaen
member of the prokaryotic domain Archaea
bacterium
member of the prokaryotic domain Bacteria
critical thinking
mental process of judging info before accepting it
eukaryote
organism whose cells characteristically have a nucleus
fungus
type of eukaryotic consumer that obtain nutrients by digestion and absorption outside the body
genus
a gorup of species tha share a unique set of traits
plant
a multicelled, typically photosynthetic producer
prokaryote
single-celled organism in which the DNA is not contained in a nucleus
protist
diverse group of simple eukaryotes
science
systematic study if nature
species
a type of organism
hypothesis
testable explanation of a natural phenomenon
law of nature
generalization that describes a consistent natural phenomenon for which there is incompolete scientific explanation
model
system similar to an object or event that cannot itself be tested directly
prediciton
a statement, based on a hypothesis, about a ocndition that should exist if the hypothesis is not wrong
scientific theory
hypothesis that has not been disproven after many years of rigorous testing, andi is useful for making predicitons about other phenomena
control group
a group of objects or individuals that is identical to an experimental groups for one variable
experiment
a test designed to support or falsify a prediciton
experimental group
a gorup of objects or individuals that disply or are exposed to a variable under investigation
variable
a characteristc or event that differs among individuals
sampling error
differences between results derived form testing an entire group or individuals, and results derived from testing a subset of the group
statistically significant
refers to a result that is statistically unlikely to have occured by chance
adaptive radiation
a burst of genetic divergences form a lineage gives rise to many new species
key innovation
an evolutionary adaption that gives its bearer the pportunity to exploit a particular environment more efficiently or in a new way
taxon (taxa)
a group of orgnaisms
taxonomy
science of naming and classifying species
character
quantifiable, heritable characteristic or trait
clade
a group of species that share a set of characters
cladisitics
method of determining evolutionary relationships by grouping species into clades
cladogram
evolutionary tree diagram that shows a network of evolutionary relationships among clades
evolutionary tree
type of diagram that summarizes evolutionary relationships among a group of species
monophyletic group
an ancestor and all fo its descendants
phylogeny
evolutionary history of a species or groups of species
sistergroups
the two lineages that emerge from a node on a cladogram
hydrothermal vent
submerged opening where hot, mineral rich water streams out
protocells
membranous sacs that contain interacting organic molecules
RNA world
hypothetical eraly interval when RNA served as the material of inheritance
endosymbiosis
one species lives inside another
eukaryote
orgnaism that encloses its DNA in a nucleus; a protis, plant, fungus, or animal
ozone layer
atmospheric layer with a hgih cincentration of ozone that prevents much UV radiation form reaching Earth's surface
prokaryote
single-celled orgnaism in whihc the DNA resides in the cytoplasm; a bacterium of archaean
stromatolites
dome shaped structures composed of lauers of prokaryotic sediments; form in shallow seas
plasmid
of a prokaryote, a small ring of nonchromosomal DNA with a few genes
prokaryotic conjugation
one prokayotic cell tranfers a plasmid to another
prokayrotic fission
mehtod of asexual reproduction in which one prokaryotic cell divides and forms two identical descendant cells
strain
a subgroup within a species that has a charactersitc trait or traits
Archaea
prokaryotic domain most closley related to eukaryotes; many members live in extreme enviroments
bacteria
most diverse prokaryotic domain
decomposer
orgnaism that breaks organic material down into its inorganic subunits
extreme halophile
organism that lives where the salt concetration is high
extreme thermophile
organism that lives where the temperature is very high
methanogen
organism that produces methane gas as a meatbolic by-product
nitrogen fixation
process of combining nitrogen gas with hydrogen to form ammonia
normal flora
colelctio of microorganisms that normally live in or on a healthy animal or person
vector
animal that transmits a pathogen between its hosts
catastrophism
now-abandoned hypothesis that catastrophic geologic forces unlike those of the present day shaped earth's surface
evolution
change in a line of descent
theory of uniformity
idea that gradual, repetitive processes occurring over long time spans shaped Earth's surface
adaptation (adaptive trait)
a heritable trait that enhances an individuals fitness
fitness
the degree of adaptation to an environment, as measured by an individuals relative gentic contribution to future generations
natural selection
a process of evolution in whihc indivduals of a population who vary in the details of heritable traits survive and reproduce with differing success
bottleneck
reduction in population size so severe that it reduces genetic diversity
fixed
refers to an allel for which all emmbers of a population are homozygous
founder effect
change in allele frequencies hat occurs after a samll number of individuals establish a population
genetic drift
change in allele frequencies in a population due to chance alone
gene flow
the movements of alleles into and out of a popualtion, as by individuals that immigarte or emigrate
inbreeding
nonrandom mating among close relatives
homozygous
having identical alleles of a gene
hybrid
the offspring of a cross between tow individuals that breed true for different forms of a trait
phenotype
an individuals observable traits
dominant
refers to an allele that masks the effect of a recessive allele paired with it
genotype
the particular alleles carried by an individual
heterozygous
having two different alleles carried by an individual
recessive
refers to an allele with an effect that is masked by a dominant allele on the homologous chromosome
bell curve
bell-shaped curve; typically results from graphing frequency versus distribution for a trait that varies continuously in a population
continuous variation
a range of small differences in a shared trait
chromosome
a structure that consists of DNA and asscoiated proteins; carries part or al of a cells genetic infromation
centromere
cosntricted region in a eukaryotic chromosome where sister chromatids are attached
histone
type of protein that structurally organizes eukaryotic chromosomes
nucleosome
a lenght of DNA wiund around a spool of histone proteins
sister chromatid
one of two attached members of a duplicated eukaryotic chromosome
autosome
any chromosome other than a sex chromosme
chromosome number
the sum of all chromosomes in a cell of a given type
diploid
having two of each type of chromosome characteristic of the species
karyotype
image of an individuals complement of chromosomes arrange by size, lenght, shape, and centromere
sex chromosome
member of a pair of chromosomes that differs between males and females
DNA sequence
the order of nucleotide bases in a strand of DNA
genetically modified organism (GMO)
an organism whose genome has been deliberately mdoified
transgenic
refers to an organism that has been genetically modified to carry a gene from a different species
xenotransplantation
transplant of an organ form one species into another
eugenics
idea of deliberatelt improving the genetic qualities of the human race
gene therapy
the transfer of a normal or modified gene into a individual with the goal of treating a genetic defect of disorder
gene
part of a DNA base sequence; specifies an RNA or protein product
gene expression
process by which the information in a gene becomes converted to an RNA or protein product
messenger RNA (mRNA)
type of RNA that has a protein buling message
transcription
process by which RNA is assembled from nucleotides using the base sequence of a gene as a template
translation
process by which a polypeptide chain is assembled from amino acids in the order specified by an mRNA
promoter
in DNA, a sequence to which RNA polymerase binds
RNA polymerase
enzyme that carries out transcription
directional selection
mode of natural selection in which phenotypes at one end of a range of variation are favored
stabilizing selection
mode of natural selction in which in which intermediate phenotypes are favored over extremes
disruptive selection
mode of natural slection that favors two forms in a range of variation; intermediate forms are slected against
fossil
physocal evidence of an organism that lived in the ancient past
half-life
chractersitc time it takes ofr half of a quantity of a radioisotope to decay
lineage
line of descent
radiometric dating
method of estimating the age of a rock or fossil by measuring the ocntents and proportions of a radioisotope and it daughter elements
geologic time scale
chronolog of Earth history
Gondwana
supercontinent that formed more than 500 million years ago
Pangea
supercontinent that formed about 237 million years ago and broke up about 152 million years ago
plate tectonics
theory that earths outer layer of rock is cracked into plates, the slow movement of which rafts continents to new locations over geologic time
analogous structures
similar structures that evolved separtately in different lineages
homologous structures
similar body parts that reflect shared ancestry among lineages
morpholoical convergence
evolutionary pattern in which similar body parts evolve separately in different lineages
morphological divergence
evolutuionary pattern in which a body part of an ancestor changes in its descendants
reproductive isolation
absence of gene flow between populations; part of speciation
speciation
process by which new species arise from existing species
allopatric speciation
speciation pattern in which physical barrier that spearates members of a population ends gene flow between them
sympatric speciation
pattern in which speciation occurs in the absence of a physcial barrier