Topic 5: Energy Transfer and Nutrient Cycles

Question 1

What is biomass?

Answer 1

Matter from recently living organisms used for bioenergy production

Question 2

Name one way energy is transfered through the living organisms?

Answer 2

When organisms eat each other organisms

Question 3

How is biomass measured?

Answer 3

Measured in terms of the mass of carbon that an organism contains or the dry mass of its tissue per unit area

Question 4

What is dry mass?

Answer 4

Mass of the organism with the water removed

Question 5

Why is dry mass more reliable than wet mass?

Answer 5

Water content of living tissue varies, so mass would constantly be changing

Question 6

How do you workout dry mass?

Answer 6

Sample is dried, often in an oven set to a low temp sample is weighed at regular intervals.
Once the mass becomes constant you know that all the water has been removed

Question 7

How much percenTage does mass of carbon taken is to be of the dry mass?

Answer 7

50%

Question 8

What is the unit for dry mass?

Answer 8

Kgm-2

Question 9

What are pests?

Answer 9

Organisms that reduce the amount of energy available for crop growth and decrease NPP of crops

Question 10

What is bad about pests?

Answer 10

Reduce the amount of energy available for humns

Question 11

How can you kill pests?

Answer 11

Using chemical pesticides and biological agents
So crops lose less energy and biomass, increased efficiency of energy transfer to humans

Question 12

How can you reduce respiratory loss?

Answer 12

By controlling condition that they live in, more of their energy is for growth
Less is lost through respiration

Question 13

What is good about reducing respiratory loss?

Answer 13

More food can be produced in a shorter space of time, often at a lower cost

Question 14

What is bad about reducing respiratory loss?

Answer 14

Raises ethical issues, people think conditions cause the animals pain or distress

Question 15

What is an example of how to reduce respiratory loss?

Answer 15

Animals to be kept in pens and often kept warm

Question 16

What happens as you move up a food chain (energy transfer)?

Answer 16

Becomes more efficient

Question 17

What do food chain/webs do?

Answer 17

Show how energy is transferred through an ecosystem

Question 18

What are the stages in a food chain called?

Answer 18

Trophic level

Question 19

What do decomposers do?

Answer 19

Break down dead or undigested material, allowing nutrients to be recycled

Question 20

What do most farming practices aim to increase?

Answer 20

Aim to increase the amount of energy that is available for human consumption

Question 21

How do we increase the amount of energy that is available for human consumption?

Answer 21

Increasing NPP of crops and NP of livestock

Question 22

How can you increase NPP of crops?

Answer 22

Energy lost to other organisms (pests reduced through simplification of food webs)

Question 23

How can you increase NP of respiration?

Answer 23

Energy lost through the respiration of livestock can be reduced

Question 24

How do consumers get energy?

Answer 24

Ingesting plant material, or animals that have eaten plant material

Question 25

What % of energy is lost through each tropic level?

Answer 25

90%

Question 25

Why is so much energy lost through each trophic level?

Answer 25

Some parts are indigestible, so are egested as faeces Chemical energy stored in there parts is lost to the environment some lost through respiration

Question 26

What is the equation for net production?

Answer 26

Chemical energy in ingested food - (chemical energy lost in faeces and urine + energy lost through respiration)

Question 27

What is another name for net production?

Answer 27

Secondary production

Question 28

What is the equation of % efficiency of energy transfer?

Answer 28

(Net production of trophic level/net production of previous trophic level) x 100

Question 29

What does GPP stand for?

Question 30

What is GPP?

Answer 30

Gross primary productivity

Question 31

What is GPP?

Answer 31

Total amount of chemical energy converted from light energy by plants in given area

Question 32

What is the energy lost to the environment as heat when plants respire called?

Answer 32

Respiratory loss

Question 33

What is the remaining chemical energy called?

Answer 33

Net primary productivity

Question 34

What is the equation of NPP?

Answer 34

NPP= (GPP-R)

Question 35

What is primary productivity?

Answer 35

When primary production is expressed as a rate

Question 36

What are the typical units for primary productivity?

Answer 36

KJ ha-1 yr-1/KJ m-2 yr-1

Question 37

What is NPP?

Answer 37

The energy available to the plant for growth and reproduction

Question 38

What % of GPP is lost to the environment as heat?

Answer 38

50%

Question 39

What does an ecosystem include?

Answer 39

All the organism living in a particular area and all the non-living (abiotic) conditions

Question 40

What makes up biomass an how is it formed?

Answer 40

During photosynthesis plants use energy and co to make glucose and other sugars. Some of the sugars produce during photosynthesis are used in respiration to release energy for growth, rest of the glucose used to make other biological molecules make up the plants biomass

Question 41

What is biomass?

Answer 41

Mass of living material

Question 42

What else can biomass be thought of as?

Answer 42

Chemical energy stored in the plants

Question 43

Whats a consumers net production?

Answer 43

Energy available for the next trophic level

Question 44

What is an example of a food chain (general)?

Answer 44

Producers, primary consumers, secondary consumer and tertiary consumers

Question 45

Is it a you move up/down food chains that it becomes more efficient?

Answer 45

Moving up

Question 46

What do farmers use to reduce pests?

Answer 46

Pesticides, biological agents and intergrated chemical and biological method systems

Question 47

How do you reduce respiratory loss?

Answer 47

Controlling the conditions they live in o more of their livestocks energy is used for growth and less through respiration Animals kept in pens where their movement is restricted, indoors and warm no wasting energy through body heat

Question 48

What are microorganisms an example of?

Answer 48

Saprobionts

Question 49

What 2 things do saprobionts do?

Answer 49

Feed on remains of dead pants and animals and on own waste They secrete enzymes and digest their food externally

Question 50

What is it called when food is digested externally?

Answer 50

Extracellular digestion: Organic molecules are broken down unto inorganic nutrition

Question 51

What is mycorrhizae?

Answer 51

The symbiotic relationships with the roots of plants

Question 52

What is a hyphae?

Answer 52

Fungi made up of long, thin strands connecting plants roots

Question 53

What does hyphae do?

Answer 53

Greatly increase SA of plants roots system, helping the plants absorb ions from soil that are scarce

Question 54

Why do plants and animals need nitrogen?

Answer 54

Make proteins and nucleic acid

Question 55

How much of our atmosphere is made up of nitrogen?

Answer 55

78%

Question 56

How are plants and animals able to use the nitrogen?

Answer 56

Can't use it as N2 gas bacteria must convert it into nitrogen-containing compounds first

Question 57

What does the nitrogen cycle show?

Answer 57

How nitrogen is converted into a usable form passed between living organisms and that non-living environment

Question 58

Why do plants and animals need phosphours?

Answer 58

Make biological molecules e.g phospholipids

Question 59

Where is phosphate found?

Answer 59

Rocks and dissolved in water in the soil, dissolved in oceans to form phosphate ions

Question 60

Why do crops take in minerals?

Answer 60

Grow and use them to build their own tissues

Question 61

When crops are harvested what happens to minerals?

Answer 61

Crops are removed from the field where they're grown rather than being allowed to die and decompose there So the minerals ions they contain aren't returned to the soil by decomposers in nitrogen

Question 62

What do fertilisers do?

Answer 62

Fertilisers replace the lost minerals, so more energy from the ecosystem can be used for growth to increase efficiency of energy transfers

Question 63

What are the 2 types of fertilisers?

Answer 63

Natural and artificial

Question 64

What do natural fertilisers contain?

Answer 64

Contain pure chemicals as powders or pellets

Question 65

What do natural fertilisers do?

Answer 65

Include manure, composted veg, crop residues and sewage sludge

Question 66

What happens when more fertiliser is applied that the plants are able to use?

Answer 66

Leaching into waterways

Question 67

What is leaching?

Answer 67

When water-soluble compounds in the soil are washed away by rain. Leading to eutrophication

Question 68

What makes leaching occur more?

Answer 68

Inorganic ions in chem fertilisers are very soluble Meaning that more likely to leach into waterways Also, more likely to occur if fertiliser is applied just before heavy rainfall

Question 69

What type of fertiliser is less likely to cause leaching?

Answer 69

Nautral

Question 70

Why do natural fertilisers make leaching less likely to occur?

Answer 70

As nitrogen and phosphorus are still contained in organic molecules that need to be decomposed by microorganisms before they can be absorbed by plants

Question 71

What is more likely to cause leaching phosphates or nitrates?

Answer 71

Phosphates as they are less soluble in water