Competition and Environmental Change

Question 1

What do organisms compete for?

Answer 1

Resources to survive

Question 2

What do plants need to survive?

Answer 2

Light, space, water and minerals (nutrients) from soil

Question 3

What do animals need to survive?

Answer 3

Space (territory), food, water and mates

Question 4

Living factors which cause environmental change?

Answer 4

• A change in the occurence of infectious disease
• A change in the number of predators
• A change in the number of prey or the avaliability of food sources
• A change in the number or types of competetors

Question 5

Non-living factors which cause environmental change?

Answer 5

• A change in average temperature
• A change in average rainfall
• A change in the level of air and water pollution

Question 6

3 ways in which environmental factors affect populations?

Answer 6

They either increase, decrease of the distribution changes

Question 7

How can an environmental factor cause the popultion size to increase?

Answer 7

Eg if the number of prey increases, then there’s more food avaliable for predators, so more predators survive and reproduce and their numbers increase too

Question 8

How can an environmental factor cause the population to decrease?

Answer 8

Eg for decrease in bee’s in USA:

Pesticides

Less food avaliable

More disease

Question 9

What is a change in distribution?

Answer 9

A change in where an organism lives

Question 10

How can an environmental factor cause the population distribution to change?

Answer 10

Eg rise in temperature changes migration pattern

Question 11

How can environmental changes be measured?

Answer 11

By living indicators

Question 12

What are indicator species?

Answer 12

Species which are very sensitive to changes in their environment and so can be studied to see the effect of human acitivites

→ Invertebrates (water) and lichens (air)

Question 13

How can you measure the effect of sewage being released into a river?

Answer 13

If raw sewage is released into a river, the bacterial population in the water increases and uses up oxygen

→ some invertebrate species (like mayfly larve) and good indicators of water pollution because they’re very sensitive to the concentration of dissolved oxygen in the water, if you find mayfly larve it indicated that the water is clean

Question 14

4 non-living ways to measure environmental change? Explain them

Answer 14

• Using satellites to measure temperature of the sea surface and the amount of snow and ice cover

→ These are modern, accurate instruments and give us a global coverage

• Automatic weather stations tells us the atmospheric temperature at various locations

→ They contain thermometers that are sensitive and accurate - they can measure to very small fractions of a degree

• Measuring rainfall using rain gauges, to find out how much the average rainfall changes year on year
• Using dissolved oxygen metres, which measire the concentration of dissolved oxygen in water to discover how the level of water pollution is changing