B7 Ecology Flashcards Preview

gcse bio aqa 1d > B7 Ecology > Flashcards

Flashcards in B7 Ecology Deck (42):
1

Define the term ecosystem.

An ecosystem includes all of the living things interacting with each other, and also with their non-living environment.

2

Give an Example of an Abiotic factor

Abiotic factors are the non living components of an ecosystem so things such as the soil pH, light levels, wind speed, water content etc.

3

Define a 'Community'

A group of organisms or a population of different species occupying a particular area.

4

Name a producer on this food web

The Grass.

5

Name a secondary consumer on this food web.

snake or lizard

6

What are the mising labels on the water cycle? Starting with the arrows up from the sea to the sun and working clockwise.

Evaporation, Condensation, precipitation.

7

What is a detritovore?

An organism that eats detritus (decaying matter).

8

What is a saprophyte?

A fungus or plant which feeds on detritus by secreting enzymes which help digest the detritus.

9

Name a process which locks carbon away.

Photosynthesis or sedimentation

10

Name a process which adds carbon to the carbon cycle

Respiration or Combustion

11

What does 'biodiverse' mean?

An area with a large number of different species living there.

12

What is a pesticide?

A chemical which kills pests, used in farming methods.

13

What is a herbicide?

A chemical used in agriculture which kills weeds.

14

What can cause algal blooms in lakes and result in Eutrophication?

Fertilisers

15

Name a gas responsible for causing acid rain.

Sulpher or nitrogen oxides.

16

What produces sulphur dioxide responsible for acid rain?

Cars and factories.

17

Name an effect of acid rain on the environment.

Limestone buildings and grave stones worn away, trees die, lakes too acidic for fish to survive.

18

Name a fossil fuel

natural gas, coal, oil.

19

What effect does the action of destroying peat bogs have on the gases in the atmosphere?

Increases the amount of carbon dioxide.

20

Describe one effect of deforestation on the environment.

Destroys habitats

reduces biodiversity

disruption of food chains

21

Name a gas responsible for Global warming.

Carbon dioxide, Methane.

22

Biodiversity can be reduced by these things:

H

I

P

P

O

Habitat destruction

Invasive species

Pollution

Population Increase

Overharvesting

 

23

What are Trophic Levels?

TRIPLE ONLY

They are the feeding levels within a food chain.

24

What is a top or 'Apex' predator?

TRIPLE ONLY

A predator that has no predators of its own.

25

Where is trophic level one found on a pyramid of biomass?

 

TRIPLE ONLY

At the bottom.

26

Approximately how much biomass is transferred from one trophic level to another?

TRIPLE ONLY

10%

27

How is the energy lost at each trophic level?

TRIPLE ONLY

MRS GREN

Movement, Respiration, Senses, Growth, Excretion, Nutrition

28

Why is most energy lost between the transfer from producer to consumer?

TRIPLE ONLY

Much of the plant material (cellulose) is indigestible and is simply excreted.

29

Calculate the missing respiration value.

TRIPLE ONLY

100-63-4 =33KJ

30

Calculate the efficiency for this diagram.

TRIPLE ONLY

Only 4 kJ of the original energy available to the bullock is available to the next stage, which might be humans. The efficiency of this energy transfer is:

efficiency = 4⁄100 × 100 = 4%

31

Give two possible negative effects of the decrease in forest cover on ecosystems.

any two from:

•        decreased biodiversity

•        loss of habitats

•        increased carbon dioxide (concentration)

•        global warming

32

Define three biotic factors which affect an ecosystem.

Any three from

availability of food • new predators arriving • new pathogens • one species outcompeting another so the numbers are no longer sufficient to breed.

33

What are 'extremophiles'?

Some organisms live in environments that are very extreme, such as at high temperature, pressure, or salt concentration.

Bacteria living in deep sea vents are extremophiles.

34

What are the conditions needed for rapid decay?

 

TRIPLE ONLY

Heat, Moisture and Oxygen.

35

Which gas is produced in anaerobic decay?

 

TRIPLE ONLY

Methane Gas

36

How does a biogas generator work?

 

TRIPLE ONLY

They canbe used to produce methane gas as a fuel.

37

Why has large scale deforestation in tropical areas occured?

Large-scale deforestation in tropical areas has occurred to:

 provide land for cattle and rice fields 

grow crops for biofuels

38

What is 'food security'?

TRIPLE ONLY

Food security is having enough food to feed a population.

39

Decsribe 2 factors which are affecting food security.

TRIPLE ONLY

2 answers from here:

Biological factors which are threatening food security include: 

the increasing birth rate has threatened food security in some countries

• changing diets in developed countries means scarce food resources are transported around the world

• new pests and pathogens that affect farming

• environmental changes that affect food production, such as widespread famine occurring in some countries if rains fail

• the cost of agricultural inputs

• conflicts that have arisen in some parts of the world which affect the availability of water or food.

40

Describe one way in which the efficency of cattle farming could be improved.

TRIPLE ONLY

The efficiency of food production can be improved by restricting energy transfer from food animals to the environment.

This can be done by limiting their movement and by controlling the temperature of their surroundings

41

Describe two methods which maintain fish stocks at sustainable levels.

TRIPLE ONLY

Control of net size and the introduction of fishing quotas play important roles in conservation of fish stocks at a sustainable level.

42

What is the name of the fungus used to produce mycoprotein?

 

TRIPLE ONLY

The fungus Fusarium is useful for producing mycoprotein