Energy Flow

Question 1

Gross primary productivity

Answer 1

• producers
• total energy available for primary consumers to gain from the producers
• rate at which the producers produce organic molecules by photosynthesising

Question 2

Equation for net primary production

Answer 2

NPP = GPP-R

GPP = gross primary production
R = respiration

Question 3

How do you measure biomass?

Answer 3

• dry organisms
• use oven
• mass of carbon or dry tissue per area
• but requires sacrificing organism so has ethical questions

Question 4

Secondary productivity key words

Answer 4

• detritus = DOM
• detritivores = reduce surface area of DOM for decomposers
• saprophytes = decomposers

Question 5

How is energy lost between tropic levels

Answer 5

• not all of each organism is consumed e.g. hair and teeth
• thermal energy lost
• faeces of aminal

Question 6

Equation for net production

Answer 6

N = I - ( F + R )

Net production = chemical energy store of food - (energy lost in faeces + energy lost in respiration)

Question 7

% efficiency

Answer 7

Energy available after transfer / energy available before transfer x 100

Question 8

Pyramids of number

Answer 8

• shows number of animals in species not biomas
• doesn’t show energy loss
• can get inverted pyramids

Question 9

Pyramids of biomass

Answer 9

• in kg
• mass of creature in each level
• may have different energy levels in comparison to their masses
• have to empty (starve) and dry organisms to get true biomass but that has ethical issues

Question 10

Pyramids of energy

Answer 10

• kj
• energy passed from one organism to another and what is lost
• taken at a given time
• more reliable as it shows energy levels in equal bars

Question 11

How to increase productivity of intensive farming

Answer 11

• for cattle, heat pens, antibiotics, steroids to produce more meat, and high protein diet
• monocultures require rich fertiliser, pesticides, and more space which requires hedgerow removal of