distribution of organisms Flashcards
where do organisms in general live and why ?
-live in places because the environment varies
what is the distribution of organisms ?
where an organisms are found
give five example of environmental factors that can effect where an organism lives ?
- temperature
- availability of oxygen and carbon dioxide
- amount of light
- availability of nutrients
- availability of water
where mights daises be found and why ?
found in open areas with lots of light
not under trees as they are much darker
daisies need lots of light to photosynthesise
what are the two ways to study distribution of organisms ?
- quadrat = measure how common an organisms in 2 areas
- using a quadrant along a transect = study distribution changes across an area
what do you do with a quadrat ?
- place the quadrat down and count the organisms
- place the quadrat in down in a close area but is different
what is a quadrat ?
- it is a square frame enclosing a known area
what are the four stages of a belt transect along a shore ?
- lower shore
- middle shore
- upper shore
- splash zone
heres an example on how to work out a quadrat ?
There are four dandelion plants inside a 0.25 m2 quadrat. The whole field is 50 m2 in area. The estimated population size of dandelions in the field would be:
4 × (50 ÷ 0.25) = 4 × 200 = 800
what is the AFCOR scale ?
-Abundant -> 90%
-Common -> 70 %
-Frequent -> 50%
Occasional ->30 %
what is a transect for ?
-To study the distribution of organisms along a line
give three examples of sampling
- river kick
- pond dippings
- pitfall traps
how can you make your transect or quadrat results more reliable ?
- take a large sample size ( bigger samples are more representative of the whole population
how can you make your transect or quadrat results more valid ?
- they must be reliable and answer the original question
- use random samples
- need to control variables otherwise won’t know if the correlation is correct and reliable
