Chapters 19 and 21: Trophic levels and organisation of an ecosystem Flashcards Preview

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Flashcards in Chapters 19 and 21: Trophic levels and organisation of an ecosystem Deck (37):
1

What is a community??

What is a population??

2

What is a community?

A group of two or more populations of different species living at the same time in the same place

3

What is a population?

The total number of organisms of the same species or similar species that live in the same place

4

What is an ecosystem?

A community of living organisms in their environment

5

What is sampling?

The process of recording a small amount of information and then extrapolating it to make wider conclusions

6

What is a quadrat?

A square 0.25 m² frame used in biological sampling

7

List three ways in which organisms can be recorded?

Counting the number of individual organisms, Counting the number of different species (indication of biodiversity), Recording the percentage cover of a plant such as grass

8

How would you decide where to place a quadrat?

By generating two random numbers. The first random number tells you how far to walk forwards and the second random number tells you how far to walk sideways. This method of randomly placing the quadrat allows you to remove all forms of bias from your results

9

What are concordant results?

Results that are similar

10

What is systematic sampling?

Placing quadrants in a systematic way. You would do this when you want to check whether the distribution of an organism changes in an area

11

What is systematic sampling?

Placing quadrants in a systematic way. Yu would do this when you want to check whether the distribution of an organism changes in an area

12

How would you carry out systematic sampling using quadrants?

If you wanted to look in more detail about how seaweed is distributed on the seashore you could use systematic sampling. You would draw a line called a transect from the top of the shore to the bottom and systematically place your quadrat on this line every meter and record the number of seaweed species

13

What is a producer?

Any organism that photosynthesises such as a plant or algae

14

What is an inorganic compound?

A compound that does not contain carbon

15

How can organisms obtain the energy they need to live?

They can create energy through photosynthesis they can consume other living organisms that have produced this energy store or they can obtain by eating the bodies of dead organisms

16

What is a consumer?

Organisms that obtain energy by eating another organisms. They are split into two groups; carnivals and herbivores

17

What are decomposers?

Any organism that breaks down the remains of a dead organism through the process of decomposition. Bacteria are very important decomposers. Fungi are also decomposers

18

What is the reaction for burning natural gas?

Methane + oxygen => carbon dioxide + water

19

What are the four separate processes in the carbon cycle?

Photosynthesis, respiration, combustion and decay

20

What happens with plants and animals die?

Their biomass is decomposed by bacteria, a process which produces carbon dioxide waste which is released back into the atmosphere. Mineral ions are also released back into the soil

21

What is precipitation?

Rain, snow, hail and sleet

22

What is run-off?

The movement of water across the surface of land

23

What is infiltration?

The movement of water into the ground to become groundwater

24

What is subsurface flow?

The movement of underground water towards the seas and oceans

25

What are aquifers?

Underground layers of rock that are permeable to water so water is naturally stored in these rocks. Run-off water can sink through these rocks by infiltration and is stored in aquifers. As well as being stored water in aquifers can move towards the ocean or back to the surface as a natural spring

26

What are the six processes in the water cycle?

Precipitation, run-off, infiltration, subsurface flow, evaporation and transpiration

27

What is decomposition?

Decomposition or decay is the breakdown of once living organisms into much smaller substances. This is essential to recycle the basic compounds such as amino acids that are needed for other life to grow

28

Which factors speed up decomposition?

Warmer temperatures, more oxygen and moisture. Decomposition also occurs faster at a neutral pH. Many decomposing organisms produce toxic waste products, and the buildup of these can reduce the rate of decomposition

29

What is a bio-indicator?

An organism whose presence or absence tells you about the cleanliness of an ecosystem

30

What is a bioindicator?

An organism whose presence or absence tells you about the cleanliness of an ecosystem

31

What is migration?

The annual movement of animals (often birds) over large distances for food, breeding sites, or warmer temperatures. Some fish such as salmon are born in freshwater rivers, migrate to the sea to live, and return to the freshwater to reproduce

32

What way are lichens bio-indicators?

They can only grow large or in high numbers in clean air

33

What way are lichens bioindicators?

They can only grow large or in high numbers in clean air

34

What is a trophic level?

A stage in a feeding relationship representing an organism in a food chain or a group of organisms in a food web

35

What is an apex predator?

The final organism in a feeding relationship

36

What are the levels in a food chain?

Primary producer, primary/secondary/tertiary consumer, apex predator

37

What is pyramid of biomass?

A graphical way of representing the total biomass of organisms at each level of the feeding relationship/food chain. The biomass decreases by 90% for each level you go up the pyramid (e.g. 100000kg of grass, 10000kg of rabbits, 1000kg of foxes)