Bio unit 3 notes 2

define extinction

when a type of organism is completely lost from the planet

what happens to the variety of species in a biosphere if something goes extinct

varity decreases

define biodiversity

the variety of life in an area

does high biodiversity make an ecosystem more stable or less

more stable

what are the three types of biodiversity

genetic

species

ecosystem

why is biodiversity important

because it gives direct economic value to humans

what would hypothetically if a plant went extinct

if it gave us medicine then we would forever be out of a medicine

why do we need genetic diversity

bc if disease happens and one species goes extinct then its all gone and we might need the species

what do plants provide

oxygen

carbon dioxide

what do living things protect us from

floods

pollution

on average how many species go extinct a year

1-2

how many new species are added per year

2-3

what is “normal” extinction called

background bc we don’t notice it

what type of extinction is not normal

mass extinction

what is mass extinction

when a lots of species go extinct in a short period of time

what and when was the last mass extinction we had

dinosaurs 65 million years ago

what percent of all species went extinct

75%

t or f: we are currently undergoing a mass extinction

true

what is our current extinction rate

1000 time the normal extinction rate

what is causing our current mass extinction

humans

what is over exploitation of species

over hunting

over fishing

what four species have been hunted or fished to extinction

tasmanian tiger

bison

passenger pidgeons

white rhinos

t or f: habitat loss is the greatest threat to species

true

what exces nutrients gets into lakes bc of runoff

nitrogen

phosphorus

what is a dead zone

a place in water where there is no oxygen so nothing can live

what is eutrophication

it is what happens when you get a dead zone

what causes climate change

excess carbon dioxide in the atmosphere

how do we get excess carbon dioxide

burning of fossil fuels

how much has the plant warmed since 1880 and then by 2040

1.5 degrees Celcius

why is 1.5 degrees a big deal

leads to extreme weather