Energy and Ecosystems

Question 1

what is a producer

Answer 1

photosynthetic organisms
that manufacture organic substances using light energy,water,carbon dioxide
and mineral ions

Question 2

what is a primary consumer

Answer 2

organisms that consume producers

Question 3

what is a secondary consumer

Answer 3

an organism that consumes a primary consumer

Question 4

what is a tertiary consumer

Answer 4

an organism that consumes a secondary consumer

Question 5

what is a consumer

Answer 5

organisms that obtain energy by feeding on other organisms rather than using sunlight directly

Question 6

what is a trophic level

Answer 6

a level in a food chain

Question 7

what is biomass

Answer 7

the total mass of living material in a specific area in a given time

Question 8

why is using dry mass better than bio mass

Answer 8

bio mass involves the water levels which vary day to day

Question 9

how do you remove the water from an organism

Answer 9

weigh and heat sample so water evaporates

heat until mass remains constant

Question 10

what % of the light energy from the sun is converted to chemical energy in plants

Answer 10

1-3%

Question 11

give 4 reasons why all of the light energy from the sun is no converted to chemical energy in plants

Answer 11

1. not all wavelengths of light are absorbed
2. some light is adsorbed or reflected by clouds or atmosphere
3. light may not fall on a chloroplast molecule
4. temperature or CO2 conc may limit the rate of photosynthesis

Question 12

what are saprobionts

Answer 12

fungi and bacteria that

break dead and waste material

Question 13

what % of energy at each stage of the food chain

Answer 13

10%

Question 14

what do saprobionts do to do dead and waste matter

Answer 14

the secrete enzymes onto dead and waste material to break it down

Question 15

what do saprobionts do to organic molecules

Answer 15

organic molecules are broken down into inorganic molecules

Question 16

what do saprobionts do to smaller molcules

Answer 16

they absorb smaller molecules and use them for storage/respiration

Question 17

outline nitrogen fixation

Answer 17

nitrogen-fixing bacteria

covert nitrogen gas to ammonium ions

Question 18

outline nitrification

Answer 18

nitrifying bacteria convert ammonium ions to nitrite ions and then nitrite ions to nitrate ions

Question 19

how are phosphate ions in rocks released into the soil

Answer 19

phosphate ions in rocks are released into the soil by weathering

Question 20

what do plants do to the phosphate ions that are released into the soil

Answer 20

they take up phosphate ions through their roots

mycorrhizae greatly increase the rate at which phosphate can be assimilated

Question 21

what is mycorrhizae

Answer 21

a symbiotic relationship between plants and fungi benefitis both species

Question 22

what happens to the phosphate ions after plants absorb them

Answer 22

phosphate ions are transferred through the food chain as animals eat the plant and are in turn eaten by other animals

Question 23

how are phosphate ions lost from animals

Answer 23

phosphate ions are lost from the animals in waste products

Question 24

outline assimilation

Answer 24

nitrates are used to make amino acids and proteins

Question 25

outline ammonification

Answer 25

saprobionts break down organic molecules into ammonium ions

Question 26

outline dentrification

Answer 26

dentrifying bacteria convert nitrate ions into nitrogen gas

Question 27

what happens to minerals in the soil in intensive farming

Answer 27

minerals are removed from the soil and not being returned

Question 28

why do we use fertilisers

Answer 28

to the replace the mineral ions that are removed from the soil in intensive farming

Question 29

what do saprobionts do to animals and plants when they die (phosphorous cycle)

Answer 29

they are involved in the breaking down the organic compounds, releasing phosphate ions into the soil for assimilation by plants they also release the phosphate ions from urine and feaces

Question 30

how are phosphate ions released into rivers and how are they taken up

Answer 30

weathering of rocks releases phosphate ions into rivers

they are taken up by aquatic producers such as algae and passed along the food chain to birds

Question 31

what is the waste produced by sea birds called and what it is it’s role in phosphorous cycle

Answer 31

it is called guano and contains a high proportion of phosphate ions it returns a significant amount of phosphate ions to soils

Question 32

what are the two types of fertilisers

Answer 32

natural organic fertilisers

artifical inorganic fertilisers

Question 33

what are natural organic fertilisers made from

Answer 33

dead and dying plants as well as plants and animal waste

Question 34

what are artifical inorganic fertilisers made from

Answer 34

rocks that have been mined they contain NPK

Question 35

what are the problems with fertilisers

Answer 35

reduced species diversity
leaching
eutrophication

Question 36

why do fertilisers cause reduced species diversity

Answer 36

as NPK fertilisers favour the growth of rapidly growing species,grasses and nettles
as they absorb more light and compete for space far better

Question 37

outline leaching

Answer 37

fertilisers and mineral ions dissolve in rainwater and run off into lakes, rivers and streams

Question 38

what is gross primary production

Answer 38

the total amount of chemical energy converted from light energy by plants in a given area

Question 39

what are respiratory loses

Answer 39

the gross primary production lost to the environment as heat when the plants respire