Energy In Ecosystems

Question 1

What are consumers ?

Answer 1

Animals and fungi that cannot produce food from sunlight therefore they must eat other animals and plants for energy to live

Question 2

What do herbivores eat ?

Answer 2

Only plant materials (e.g. Sheep)

Question 3

What do carnivores eat ?

Answer 3

Only animal materials (e.g. Dog )

Question 4

What do omnivores eat ?

Answer 4

Mixture of plant and animal materials (e.g. Man)

Question 5

What do arrows in a food chain indicate ?

Answer 5

The direction of energy flow

Question 6

How much energy is lost at each stage in a food chain and how much energy is passed on?

Answer 6

90% lost

10% passed on

Question 7

How can energy be lost (3)

Answer 7

Movement
Heat
Undigested food

Question 8

What can be said about short food chains ?

Answer 8

More efficient

Question 9

What can we say about the greater the number of links ?

Answer 9

Less energy is passed on at each stage

Question 10

What is a pyramid of numbers ?

Answer 10

A diagram that shows the number of organisms at each level in a food chain

Question 11

What 2 trends do we see as we move up the pyramid ?

Answer 11

Number of organisms decreases

Size of organisms increases

Question 12

What does a pyramid of biomass show?

Answer 12

The total mass of all the organisms at each stage in a food chain

Question 13

What is the biomass at each level dependent on ?

Answer 13

The energy passed on at each stage in the food chain and can vary throughout the year

Question 14

What is a pyramid of energy based on?

Answer 14

Productivity

Question 15

How is a pyramid of energy measured as?

Answer 15

Grams of dry mass per metre squarer per year and then is converted into energy equivalent in kJ per metre squared per year (kJ/m2/year)

Question 16

What is a pyramid of energy ?

Answer 16

A diagram that shows the amount of energy available at each level in a food chain

Question 17

What are producers ?

Answer 17

Green plants which produce their own food by changing the sun’s light energy into chemical energy by photosynthesis

Question 18

Why is nitrogen an essential element ?

Answer 18

Used to make DNA , amino acids and proteins

Question 19

What percentage of the air is nitrogen ?

Answer 19

80%

Question 20

What form do green plants absorb nitrogen ?

Answer 20

Nitrates from the soil and use it to make proteins

Question 21

What is the nitrogen cycle is essential to provide ?

Answer 21

Nitrates for plants to absorb and use

Question 22

What does the nitrogen cycle ensure ?

Answer 22

A continuous supply of nitrogen for years to come

Question 23

What does nitrogen fixing bacteria do?

Answer 23

Convert nitrogen gas to nitrate

Can be found in root nodules of clover plant s

Question 24

What do decomposers do ?

Answer 24

Convert protein to ammonium compounds

Question 25

What do nitrifying bacteria do ?

Answer 25

Some convert ammonium compounds to nitrites and some convert nitrites to nitrates

Question 26

What do denitrifying bacteria do?

Answer 26

Convert useful nitrates to nitrogen gas

Question 27

What is competition ?

Answer 27

When 2 or more organisms require the same resource.

All living things need natural resources but there is not enough for everyone.

Question 28

What is interspecific competition ?

Answer 28

Occurs when individuals of different species in an ecosystem require similar resources

Question 29

What is intraspecific competition ?

Answer 29

Occurs between members of the same species. It can be very intense because the requirements of all individuals are identical

Question 30

Where do we find the nitrogen fixing bacteria ?

Answer 30

Nitrogen fixing bacteria LIVE in legume root nodules

Question 31

What is a food chain?

Answer 31

A diagram that shows the feeding relationships of organisms living together in a particular ecosystem

Question 32

Describe how else nitrogen fixations can take place (natural event)

Answer 32

Lightning converts atmospheric nitrogen to nitrate. This nitrate is then dissolved in rain, falls to the ground and enters the soil