allele
alternate version of a gene
gene
segment of dna that codes for a specific trait
loci
number of base pairs to where a gene is located
genotype
letters
phenotype
the physical expression of a gene or group of genes
what is the name of the process that organisms rely on for growth?
mitosis
what do we name the process that organisms rely on for reproduction?
meiosis
mitosis
repairs and replaces damaged cells and tissue, makes an exact copy of the cell
meiosis
used to produce gametes, not an exact copy
evolution
the change in the inherited characteristics of biological populations
natural selection
individuals in a population that are most fit
chromatin
material that chromosomes are composed of
chromosome
carries genetic information, threadlike structure of nucleic acids and protein
mutations
chance alteration of dna, creates new alleles
fitness
an individuals successes in passing on genes to offspring
gene frequency
percentage if each allele in a population
what is a species?
groups of actually or potentially interbreeding natural populations that are reproductively isolated from other groups
does meiosis or mitosis contribute to adding more alleles to a population?
meiosis
how do natural selection and evolution result in the creation of a new species
organisms adapt to their environment and pass it on to their offspring
what tends to make the process of speciation so slow and difficult
geographical isolation, genetic drift, natural selection
name two processes that contribute to the formation of new species from a single population
allopatric and sympatric speciation
how can populations of a same species live in the same area and become isolated from each other
allopatric speciation, mountains, oceans, rivers
what are the four hazards and risks?
physical, chemical, biological, cultural
examples of physical hazards and risks
floods, radon, uv exposure
examples of chemical hazards and risks
pesticides, disinfectants
examples of biological hazards and risks
viruses
examples of cultural hazards and risks
drinking, smoking
some characteristics of all living things
respond to the environment, homeostasis, possess dna, reproduce, evolve
virus
a microscopic infectious agent that is unable to grow or reproduce outside a host cell
what are some examples of lacking attributes of life
incapable of replicating independently, lack of cellular organization and metabolism, consist of rna and dna usually enclosed in a protein coat
toxin
natural poison
toxicant
man made
LD50
amount given all at once to kill 50% of the test animals over a fixed period, dermal and oral administration
LC50
amount per unit weight, usually in air or water
acute exposure
high exposure in short period of time
chronic exposure
lower amounts over a long period of time
characteristics of POPs
dont readily degrade, carbon based, readily assimilate into biological organisms, many are fat soluble
what is a POP
persistent organic pollutant
who are most at risk of POPs
fishers and hunters, men and women at childbearing age, children and elderly
carcinogen
causes cancer
mutagen
causes mutations in dna
teratogens
causes birth defects
allergens
cause extreme immune response
neurotoxins
damage nervous system
endocrine disruptors
interfere with hormones
asphyxiants
deprive tissue of oxygen
what are the types of toxicants
carcinogen, mutagen, teratogen, allergen, neurotoxin, endocrine disruptor, asphyxiant
biomagnification
at each trophic level, chemical concentration increases
bioaccumulation
increase in the concentration of a chemical in an organism over time
what are the sources of hazards
airborne, food, water
what does it mean to be an indicator species
organisms presence or absence reflects a specific environmental condition
LD50 and LC50, which is an oral dose and which is liquid or inhalation
ld50- dermal and oral administration, lc50- in air or water
what type of hazard does a hurricane represent
physical
what are two organizations the government uses to manage risk to human chemical exposure
food and drug administration and environmental protection agency
what process allows chemicals to end up in polar regions without it being used there
grasshopper effect/global distillation
why is it that it takes so long to identify toxicants that have contaminated the environment
we don't know how to test or what to look for
what is the significance of rachel carlsons "silent spring"
alerted the public that ddt and other pesticides could be toxic to animals and people
how have toxicants directly affected people in the us
cause cancer, act as endocrine disruptors, organ failure, developmental problems
hazardous waste
wastes that are flammable, corrosive, explosive, or toxic
what are major sources of solid waste generation
paper, food scraps, plastic, metal, rubber, cloth
what is the largest part of household waste
food scraps
is an open or covered dump preferred
covered
what represents some of the biggest environmental risk to landfill operation
release of methane, contamination of groundwater, anaerobic decomposition