bio

Question 1

ecosystem

Answer 1

a relative self-contained or defined area, where there is an interacting group of organisms and the environment where they live in, including both biotic and abiotic factors. they are usually self-sustaining and energy flows through the ecosystem.

Question 2

Niche

Answer 2

role of an organism and hot it fits into an ecosystem
including where it lives
how it obtains food
its interactions with biotic and abiotic factors
time it feeds
behaviour towards other organisms
no two species can have the same niche or else one will outcompete the other

Question 3

biodiversity

Answer 3

in three levels
the genetic variations within a species
variation of the different population of species in an ecosystem
variations in the types of ecosystems and habitats

Question 4

why we use samples

Answer 4

in practice, it is impossible to take measurements of the entire population, we use representative samples to make estimates. Therefore, large samples are needed because anomalies can have disproportionate effects. Smaller sample sizes would not be representative and less valid.

Question 5

The process of Quadrat sampling

Answer 5

form a grid transect across fields
use a random number generator to produce coordinates
place quadrats in fields
count the number of organisms
take the average number of organisms per quadrat
note, sometimes they trick you into thinking its a line transect but it is actually a grid transect for 2 different areas

Question 6

Mark-Release-recapture

Answer 6

detail on traps - live animal trap, bait with food/peanut butter
detail on marking-paint/clipping fur/ no adverse effects affecting its survival
sometimes you forget to describe that they are returned to the habitat for mizing to occur
Timing- not too soon mixing won’t occur and not too long they may die, get eaten, get captured or emigrate to another place
population size = N caught the first time *N caught second time/N marked the second time

Question 7

systematic sampling

Answer 7

belt or line transect
sample taken at set distances
well for measuring a change along a distance from a specific stimuli

Question 8

threats to biodiversity

Answer 8

habitat loss for degradation of the environment - and using the land for housing, transport and agriculture. Deforestation,
Overexploitation of keystone species can cause a collapse of the ecosystem by breaking a food chain or some important
Pollution - not always available in some places

Question 9

why biodiversity

Answer 9

moral and ethical reasons
ecological reasons, for stable ecosystems and maintains food chains
some plants provide us with drugs
helps country’s economy with ecotourism