Ecology

Question 1

what is ecology?

Answer 1

the study of ecosystems

Question 2

what is an ecosystem?

Answer 2

an easily described system or area where organisms interact with their physical environment

Question 3

producer definition

Answer 3

organisms which make their own food e.g. photosynthesising plants

Question 4

consumer definition

Answer 4

organisms which eat other living things e.g. animals

Question 5

decomposer definition

Answer 5

organisms which secrete digestive enzymes to decay dead organic matter to obtain their food; they help to recycle nutrients

Question 6

what is a physical environment?

Answer 6

all the non-living (abiotic) factors which affect growth and survival of living things e.g. temperature, carbon dioxide, oxygen concentrations, minerals in soil

Question 7

habitat definition

Answer 7

the places where specific organisms live

Question 8

population definition

Answer 8

the total number of individuals of one species in a particular habitat at a particular time

Question 9

what is a quadrat?

Answer 9

a square that measures that amount of population in a small area

Question 10

how do we measure population?

Answer 10

-> place the quadrat on the ground
-> count the number of individuals of our chosen species inside the square
-> individuals that are on the edge (half in half out) - only count overlapping individuals on top and left sides

Question 11

how do you find out the population of a species in a habitat?

Answer 11

1. calculate the area of the habitat
2. measure the number of individuals in one quadrat and repeat many times to check our result is reliable (at least ten quadrats are needed)
3. calculate the average number of individuals in a quadrat
4. calculate how many quadrats fit into the total area
5. multiply the result from step 4 by the result from step 3

Question 12

how do we make sure our data is valid?

Answer 12

by using random sampling - avoids bias

Question 13

how do we take a random sample?

Answer 13

1. lay out two tape measures at right angels to make a 10m by 10m set of axes - generate pairs of random numbers between 0-10 - these are coordinates
2. use the coordinates to place your quadrat

Question 14

how to sample in an ecosystem

Answer 14

1. pick two contrasting areas and set up a grid in each, use random sampling to take repeated measurements with a quadrat and compare the average results
   OR
2. use a transect - place the quadrat at regular intervals along the transect and use to measure the number or percentage of the species