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

Question 1

What is a community??

Answer 1

What is a population??

Question 2

What is a community?

Answer 2

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

Question 3

What is a population?

Answer 3

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

Question 4

What is an ecosystem?

Answer 4

A community of living organisms in their environment

Question 5

What is sampling?

Answer 5

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

Question 6

What is a quadrat?

Answer 6

A square 0.25 m² frame used in biological sampling

Question 7

List three ways in which organisms can be recorded?

Answer 7

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

Question 8

How would you decide where to place a quadrat?

Answer 8

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

Question 9

What are concordant results?

Answer 9

Results that are similar

Question 10

What is systematic sampling?

Answer 10

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

Question 11

What is systematic sampling?

Answer 11

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

Question 12

How would you carry out systematic sampling using quadrants?

Answer 12

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

Question 13

What is a producer?

Answer 13

Any organism that photosynthesises such as a plant or algae

Question 14

What is an inorganic compound?

Answer 14

A compound that does not contain carbon

Question 15

How can organisms obtain the energy they need to live?

Answer 15

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

Question 16

What is a consumer?

Answer 16

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

Question 17

What are decomposers?

Answer 17

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

Question 18

What is the reaction for burning natural gas?

Answer 18

Methane + oxygen => carbon dioxide + water

Question 19

What are the four separate processes in the carbon cycle?

Answer 19

Photosynthesis, respiration, combustion and decay

Question 20

What happens with plants and animals die?

Answer 20

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

Question 21

What is precipitation?

Answer 21

Rain, snow, hail and sleet

Question 22

What is run-off?

Answer 22

The movement of water across the surface of land

Question 23

What is infiltration?

Answer 23

The movement of water into the ground to become groundwater

Question 24

What is subsurface flow?

Answer 24

The movement of underground water towards the seas and oceans

Question 25

What are aquifers?

Answer 25

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

Question 26

What are the six processes in the water cycle?

Answer 26

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

Question 27

What is decomposition?

Answer 27

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

Question 28

Which factors speed up decomposition?

Answer 28

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

Question 29

What is a bio-indicator?

Answer 29

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

Question 30

What is a bioindicator?

Answer 30

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

Question 31

What is migration?

Answer 31

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

Question 32

What way are lichens bio-indicators?

Answer 32

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

Question 33

What way are lichens bioindicators?

Answer 33

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

Question 34

What is a trophic level?

Answer 34

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

Question 35

What is an apex predator?

Answer 35

The final organism in a feeding relationship

Question 36

What are the levels in a food chain?

Answer 36

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

Question 37

What is pyramid of biomass?

Answer 37

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)