Ecology

Question 1

What is an ecosystem?

Answer 1

All the organisms living in a habitat and the non-living parts of the habitat.

Question 2

What are the different levels of organisation within an ecosystem?

Answer 2

Individual organisms.
Populations.
Communities.

Question 3

What are populations within an ecosystem?

Answer 3

Groups of individuals of the same species.

Question 4

What are communities within an ecosystem?

Answer 4

Many populations living together.

Question 5

What is interdependence?

Answer 5

Different species relying on another for survival.

Question 6

What are some examples of interdependence?

Answer 6

Pollination, seed dispersal, food and shelter.

Question 7

What is a stable community?

Answer 7

When all the species and environmental factors are in balance, so that the population sizes stay fairly consistent.

Question 8

What are examples of stable communities?

Answer 8

Tropical rainforests, ancient oak woodlands.

Question 9

What are abiotic factors?

Answer 9

Non-living factors that can affect a community.

Question 10

What are biotic factors?

Answer 10

Living factors that can affect a community.

Question 11

What are some examples of abiotic factors?

Answer 11

Light intensity.
Temperature.
Moisture levels.
Soil pH and mineral content.
Wind intensity and direction.
Carbon dioxide levels for plants.
Oxygen levels for aquatic animals.

Question 12

What are some examples of biotic factors?

Answer 12

Availability of food.
New predators arriving.
New pathogens/disease.
One species outcompeting another.

Question 13

What are some examples of extreme environments?

Answer 13

High temperature, high pressure, high salt concentration.

Question 14

How might scientists estimate the size of a population?

Answer 14

Using a square frame called a quadrat.

Question 15

What is a quadrat?

Answer 15

A square frame used to estimate the size of a population.

Question 16

What is a transect line?

Answer 16

A long tape, to the side of which a quadrat is placed at regular intervals to estimate the size of a population.

Question 17

What is the carbon cycle?

Answer 17

Describes how carbon is recycled in nature.

Question 18

In the carbon cycle, how is carbon returned to the atmosphere?

Answer 18

Decomposing organisms/decay.
Respiration.
Combustion.

Question 19

In the carbon cycle, how is carbon removed from the atmosphere?

Answer 19

Photosynthesis.

Consuming plants.

Question 20

What is the water cycle?

Answer 20

Describes how fresh water circulates between living organisms, rivers and the sea.

Question 21

In the water cycle, how is water returned to the air?

Answer 21

Transpiration.

Evaporation (condensation).

Question 22

In the water cycle, how is water taken from the air?

Answer 22

Precipitation.

Question 23

What is a food chain?

Answer 23

Shows feeding relationships within a community.

Question 24

What is a producer within a food chain?

Answer 24

Synthesises molecules (produces food).

Question 25

What is an example of a producer?

Answer 25

Green plant, which makes glucose molecules through photosynthesis.

Question 26

What does a predator/prey graph show?

Answer 26

How the numbers of predators and prey rise and fall in cycles.

Question 27

What organisms consume producers?

Answer 27

Consumers (primary, secondary, tertiary).

Question 28

What is biodiversity?

Answer 28

The variety of all the different species of organisms on Earth.

Question 29

How might a high biodiversity impact an ecosystem?

Answer 29

It helps it become more stable, as species depend on each other for food and shelter.

Question 30

What are some factors that may limit the biodiversity of an ecosystem?

Answer 30

Availability of water.
Temperature.
Atmospheric gas.

Question 31

How might factors that limit the biodiversity of an ecosystem be due to?

Answer 31

Changes in seasons.
Geographic activity (volcanoes, storms).
Human interaction.

Question 32

Where can pollution occur?

Answer 32

In water - from sewage, fertilisers or toxic chemicals.
In air - from gases.
On land - from landfill and toxic chemicals, like pesticides and herbicides, which may be washed in land from water.

Question 33

How is acid rain caused?

Answer 33

Sulphur dioxide from gases dissolves in the moisture in the atmosphere which then precipitates.

Question 34

What can reduce the amount of land available for other animals and plants?

Answer 34

Building, quarrying, farming, dumping waste.

Question 35

What is the impact of producing garden compost?

Answer 35

It can destroy peat bogs, which houses a variety of different organisms.
It may also cause the peat bogs to decay, which would release carbon dioxide into the atmosphere.

Question 36

What do many scientists think global warming is the result of?

Answer 36

Changes in various gases (like carbon dioxide and methane), caused by pollution and deforestation.

Question 37

What are a few biological consequences of global warming?

Answer 37

Loss of habitat (when low-lying areas are flooded by rising sea levels).
Changes in the distribution of species in areas where temperature or rainfall has changed.
Changes to the migration patterns of animals.

Question 38

How might we conserve biodiversity?

Answer 38

Reducing pollution and over-exploitation.
Setting up breeding programmes for endangered species
Protecting rare habitats (like coral reefs and mangroves).
Encouraging farmers to keep margins in hedgerows and fields.
Reducing deforestation and carbon dioxide emissions.
Recycling resources, rather than dumping them in landfill.

Question 39

How does more greenhouse gases cause the temperature rise in global warming?

Answer 39

Rays from the sun reach Earth and are reflected back towards the atmosphere, but some are absorbed by carbon dioxide, and other greenhouse gases, and radiated back. This causes the heat to stay in the atmosphere for longer, warming it up.