Energy Transfer and Nutrient Cycles

Question 1

Where do plants get their energy from

Answer 1

The sun

Question 2

What is biomass

Answer 2

the mass of living material or chemical energy stored in a plant

Question 3

How can biomass be measured

Answer 3

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

Question 4

What is dry mass

Answer 4

The mass of an organism with the water removed

Question 5

Why does water have to be removed for an organism to be used as a measure of biomass

Answer 5

As the water content of living tissue varies

Question 6

How to measure dry mass

Answer 6

Dry sample of organism,(often in an oven at a low temp), the sample is weighed at regular intervals

Question 7

Why is the sample of an organism weighed at intervals when creating dry mass

Answer 7

As when the sample is at a constant weight you know all of the water has been removed

Question 8

How can the amount of chemical energy stored in biomass be estimated

Answer 8

By burning the biomass in a calorimeter, the amount of heat given off tells you how much energy is in it

Question 9

What is gross primary production

Answer 9

The total amount of chemical energy converted by plants in a given area

Question 10

How much of the gross primary production is lost to the environment

Answer 10

approximately 50%

Question 11

What is respiratory loss

Answer 11

Energy lost to the environment as heat when plants respire

Question 12

What is the equation for net primary production

Answer 12

NPP= GPP-R

Question 13

What is Net primary production

Answer 13

The energy available to the plant for growth and reproduction-the energy is stored in the plant’s biomass

Question 14

How do consumers get energy

Answer 14

By ingesting plant material, or animals that have ingested plant material

Question 15

What % of chemical energy from consumer’s food is shared to the next trophic level

Answer 15

90%

Question 16

What happens to lost chemical energy

Answer 16

Not all of the food is eaten, some is lost excreted, lost through respiration

Question 17

What is the equation for net production

Answer 17

Net Production= Chemical energy from ingested food-(Chemical energy lost in faeces and urine-Energy lost through respiration)
N=I-(F+R)

Question 18

efficiency equation

Answer 18

efficiency of energy transfer=
net production of trophic level/ net production of previous trophic level x 100

Question 19

What is used by farmers to reduce pests

Answer 19

Pesticides, biological agents, integrated systems that combine both chemical and biological methods.

Question 20

Ways farmers can decrease energy lost through respiration in livestock

Answer 20

restrict movement, indoor and warm environment

Question 21

What are the 2 things that saprobionts do

Answer 21

feed on remains of dead plants and animals and break them down
Extracellular digestion

Question 22

What is extracellular digestion

Answer 22

When they secrete enzymes and digest their food externally, then absorb the nutrients they need. Organic molecules are broken down into inorganic ions

Question 23

What is saprobiont nutrition

Answer 23

Obtaining nutrients from dead organic matter and animal waste using extracellular digestion

Question 24

What relationship is known as mycorrhizae

Answer 24

the symbiotic relationship between some fungi and the roots of plants

Question 25

What are hyphae

Answer 25

Long thin strands that make up fungi, which connect to other plants roots

Question 26

What are the benefits of hyphae

Answer 26

Increased surface area of the plants roots system, helping the plants to absorb ions from the soil Increased water uptake by the plant

Question 27

What do hyphae obtain from plants

Answer 27

Organic compounds (glucose...)

Question 28

Plants and animals need nitrogen to make

Answer 28

Proteins and nucleic acids (DNA,RNA)

Question 29

How much of the atmosphere is made up of nitrogen

Answer 29

78%

Question 30

Animals and Plants can't use nitrogen in it's natural form so it's got to be converted to

Answer 30

nitrogen containing compounds first

Question 31

What is nitrogen fixation

Answer 31

When nitrogen gas in the atmosphere is turned into nitrogen containing compounds

Question 32

What is nitrogen fixation carried out by

Answer 32

Bacteria such as Rhizobium

Question 33

What effect does Rhizobium have on nitrogen

Answer 33

It turns it into ammonia which goes on to form ammonium ions in solution that can be used by plants

Question 34

Where is Rhizobium found

Answer 34

Inside root nodules of leguminous plants,

Question 35

Rhizobium forms a mutualistic relationship with leguminous plants how

Answer 35

They provide the plant with nitrogen compounds and the plant provides them with carbohydrates

Question 36

other nitrogen fixing bacteria are found

Answer 36

in the soil

Question 37

What is ammonification

Answer 37

When nitrogen compounds from dead organisms are turned into ammonia by saprobionts, which goes on to form ammonium ions

Question 38

Animal waste also contains nitrogen compounds and can be turned into

Answer 38

Ammonia by saprobionts and go on to form ammonium ions

Question 39

What is nitrification

Answer 39

When ammonium ions in the soil are changed into nitrogen compounds that can then be used by plants(nitrates)

Question 40

First nitrifying bacteria Nitrosomonas change ammonium ions into

Answer 40

Nitrites

Question 41

Other nitrifying bacteria called nitrobacter changes nitrites into

Answer 41

Nitrates

Question 42

What is denitrification

Answer 42

When nitrates in the soil are converted into nitrogen gas by denitrifying bacteria

Question 43

During denitrification nitrates in the soil are used to carry out

Answer 43

Respiration and produce nitrogen gas, this happens under aerobic conditions

Question 44

Other ways nitrogen gets into an ecosystem

Answer 44

by lightning(which fixes atmospheric nitrogen into nitrogen oxides by artificial fertilisers(produced on industrial scale from atmospheric nitrogen by haber process

Question 45

Plants and animals need phosphorus to make biological molecules such as

Answer 45

Phospholipids, DNA, ATP

Question 46

Where is phosphorus found

Answer 46

in rocks and dissolved in the oceans in the form of phosphate ions

Question 47

Phosphate ions can be assimliated (absorbed and then used to make more complex molecules) by

Answer 47

Plants and other producers

Question 48

Phosphate ions are released into the soil by

Answer 48

Weathering

Question 49

Phosphate ions are taken into the plants through

Answer 49

The roots

Question 50

Mycorrihaze greatly increases the rate at which

Answer 50

phosphorus can be assimilated

Question 51

Phosphate ions are transferred through the food chain as

Answer 51

Animals eat the plant and are in turn eaten by other animals

Question 52

Phosphate ions are lost from the animals through

Answer 52

Waste products

Question 53

Weathering also releases phosphate ions into seas lakes and rivers, this is taken up by aquatic producers and passed on to

Answer 53

sea birds through food chain

Question 54

What is the waste produced by sea birds known as

Answer 54

Guano

Question 55

What does Guano contain

Answer 55

A high proportion of phosphate ions

Question 56

Guano returns a significant amount of phosphate ions to

Answer 56

soils and is often used as a natural fertiliser