env bio exam 4

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