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52 terms

Test 4 Bio

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Embryonic stem cells
eventually give rise to all specialized cells of the body
therapeutic cloning
transplant nucleas from patient's cells into developing embryonic stem cells and then harvest the stem cells at a very early stage. Stem cells then used to replace patient's damaged cells
Homeotic genes
program the development of organisms
oncogene
gene that causes cancer to occur
proto-oncogene
normal gene that can be converted to become an oncogene. Caused by mutation in DNA
Tumor-suppressor genes
normally inhibit uncontrolled cell division
carcinogens
cancer causing agents; changes in DNA often resul from long term exposure to these
Restriction enzymes
found in bacteria-used to cut DNA
Transformation bacteria
pick up DNA from surroundings
plasmids
rings of bacterial DNA tha can be incorporated into the bacterial cell
Recombiant DNA
2 or more sections of DNA that have been combined by humans-doesn't exist in nature
Gel electrophoresis
sorts proteins and nucleic acids by charge and size
Polymerase chain reaction (PCR)
DNA is mixed with DNA polymerase (enzyme) and nucleotides which allow the DNA to replicate
Human genomes
genome that consists of the entire make up of an individual
Evolution
the modification of populations over time-can result in new species. Considered unifying principal of biology
species
individuals that can interbreed with one another and produce offspring that can also reproduce
Natural Selection
those organisms which are best adapted to their enviornment will be more likely to survive and pss their traits down to future generations
Fitness
Measure of reproductive success: the fitest individuals are those that leave the most decedents
For selection to be an agent of evolutionary change the traits considered must:
1. Vary 2. be heritable 3. affect fitness
morphology
study of the physical forms that organisms take
homologous features
same in structure because of inheritance
embryology
study of how organisms are going to mature, from fertalization to birth
Universal triplet code
suggests that different species evolved from common ancestors
Microevolution
change in allele changes over time
Gene pool
all the alleles that exist in a given population
mutation
(agent of microevolution) permanent alterations in DNA- to affect fitness, they must be heritable. Rate of mutation is slow, most are neither harmful or beneficial. Only way entirely new information can be introduced
Gene flow
movement of alleles from one popultaion to another, occurs through migration
genetic drift
the chance alteration of allele frequencies in a population
bottleneck effect
change in allele frequency due to chance during a sharp reduction in a population size
founder effect
when a small subpopulation migrates to a new area, and starts a new population
Nonrandom mating
matin in which a given member of the popultation is not equally likely to mate with another given member
ecosystem
all the organisms in a given area and the non-living factors with which they interact
Biosphere
3 parts: atmosphere, hydrosphere (water), and lithosphere (earth and rocks)
climate
patterns of weather that prevails over years or centuries. driven by the sun
Life requires
nutrients, energy, water, appropriate temp
Intertidal and nearshore zones
steady flow of nutrients, greatest biodiversiy
photic zone
light supports photosynthesis
open ocean
most life is in the upper photic zone, life forms are pelagic-free swimming or floating
deap ocean
aphotic zone- only energy comes from organisms that swim here, the remains or products of organisms that drift down from up above or hydrothermal vents
biomes
large land areas with similair enviornmental conditions and characterestic plant communities
tropical rainforest
high temps, high rainfall, high biodiversity
savannas
little rainfall, grasses and small shrubs, large mammals
desert
low rainfall, low vegitation (if any), plants and animals adapted to conserve water
grasslands
higher rainfall than a deser, less than a forest
temperate forest
higher rainfall, dominated by trees
tundra
low rainfall, cold temperatures, slow growing vegetation
competion
neither benefit
predation
one benefits, one doesnt
parasitism
bad for host, good for parasite
mutalism
beneficial for both organisms involved
keystone species
species that have a bigger effect on their enviornment, then their abundance would suggest
Autotrophs
capture 3% of the sun's energy that reaches the surface of the earth