Ecology

Question 1

Recall what an ecosystem is

Answer 1

Ecosystem - interaction of community of organisms and the parts of their enviroment that are non-living.

Question 2

Describe which resources animals and plants compete for, and why they do this

Answer 2

Animals - food, territory and mates

Plants - light, space, minerals and water.

They compete in order to survive.

Question 3

Explain the terms ‘interdependence’ and ‘stable community’

Answer 3

Interdependence - each species in a community depending upon other species for things, e.g. pollination, food, shelter or seed dispersal.

Stable community - a community in which all species and environmental factors are in balance, so the population sizes are roughly constant.

Question 4

Name some abiotic and biotic factors that affect communities

Answer 4

Abiotic (non-living): light intensity, wind intensity and direction, moisture level.

Biotic (living): new predators, food availability and competition.

Question 5

Explain how a change in an abiotic or biotic factor might affect a community

Question 6

Represent the feeding relationships within a community using a food chain and describe these relationships

Question 7

Explain how and why ecologists use quadrats and transects

Question 8

Describe and interpret predator-prey cycles

Question 9

Required practical 9: measure the population size of a common species in a habitat. Use sampling to investigate the effect of one factor on distribution

Question 10

Describe the processes involved in the carbon cycle

Answer 10

CO2 in air → photosynthesis

Question 11

Describe the processes involved in the water cycle

Question 12

Describe what biodiversity is, why it is important, and how human activities affect it

Answer 12

Biodiversity - the variety of different species on Earth, or within an ecosystem.

Question 13

Describe the impact of human population growth and increased living standards on resource use and waste production

Answer 13

Increase in population and standard of living means more resources are used more quickly and more water produced resulting in pollution which kill plants and animals reducing biodiversity.

Question 14

Explain how pollution can occur, and the impacts of pollution

Answer 14

Pollution occurs through sewage, fertilisers and toxic chemicals (e.g. pesticides) from farming and industry get washed into water.

Smoke and acidic gases released into the atmosphere pollute the air.

Toxic chemicals (e.g. from farming) and waste dumbed into landfill sights pollute land.

The more pollution the more plants and animals killed therefore less biodiversity.

Question 15

Describe how the composition of the atmosphere is changing, and the impact of this on global warming

Question 16

Describe some biological consequences of global warming

Answer 16

Rising sea level (low-lying places may flood).

Change in distribution of some organisms.

Decrease in biodiversity (some species may become extinct).

Question 17

Describe both positive and negative human interactions in an ecosystem and explain their impact on biodiversity