Module 4 - Ecosystem Dynamics

Question 1

Impacts of biotic factors - predator/prey

Answer 1

The number of prey influence the number of predators, the abundance of each organism in the relationship varies due to food resources

Question 2

Competition

Answer 2

All organisms complete for resources, and ecosystems can only support a limited number of organisms, the organisms that gain the most resources are most likely to grow and survive

Question 3

Mutualism

Answer 3

both species in the relationship benefit from the association (+/+)

Question 4

Commensalism

Answer 4

one species benefits and the other is unaffected (+/0)

Question 5

Parasitism

Answer 5

one species benefits and the other suffers (usually non lethal damage) (+/-)

Question 6

Sampling techniques of measuring populations of organisms and how they are used

Answer 6

Transects - measures distribution, gives an estimation of organism distribution in an area
Quadrats - A quadrat is placed in an area, the number of organisms, in the quadrat is counted. If there is a large population % cover may be calculated
Capture/recapture - By tagging/marking animals, releasing and recapturing it is possible to work out an estimate of the population

Question 7

Independent, dependent and controlled variables

Answer 7

Independent - What is changed
Dependent - What is being measured
Controlled - What is kept the same

Question 8

Technologies used to determine past changes (how each work and what they tell us) - Radiometric dating

Answer 8

Radiometric dating which is the process whereby scientists determine the age in years of fossil/rock material. The parent isotope goes through radioactive decay and release energy/particles. The rate in which the decay process occurs is calculated as an equation.

Question 9

Evidence of past changes - rock painting

Answer 9

Human artistic nature gives an insight and record details of their surroundings, how they live, the animals and plants they lived with etc. This is shown through the Bradshaw paintings with show depict images of extinct megafauna.

Question 10

Geological evidence of past changes - banded iron formations

Answer 10

geological formations consisting of alternating bands of iron-rich and iron-poor sediments. Gives an idea of remnants of organic molecules/isotapic ratios only associated with living things.

Question 11

Ice core drilling

Answer 11

Evidence of the interpretation of past environments from the study of gases and other materials trapped in ice. Allows scientists to drill through ice and extract gasses that could be uses in a way of reconstructing the climate record.