Unit 3 Lesson 3: Cycling of Matter and Energy Flow

Question 1

Biomass

Answer 1

Biomass is the amount of organisms in a given area or volume in an ecosystem.

Question 2

biomass can be burned or digested to produce a type of

Answer 2

energy

Question 3

Examples of biomass that you may be familiar with include

Answer 3

wood, agricultural products, solid waste, landfill gas, biogas, and alcohol fuels such as ethanol.

Question 4

What accounts for hlaf of all biomass energy

Answer 4

Wood (including logs, wood chips, bark, and sawdust) accounts for almost half of all biomass energy.

Question 5

What does plant biomass contain

Answer 5

Plant biomass contains chemical energy from the sun that was stored during the process of photosynthesis.

Question 6

Energy and matter flow into the ecosystem through autotrophs who produce their own food, like plants that photosynthesize. What does the amount of autotrophs in an area determein

Answer 6

The amount of autotrophs in an area determines what kind and how many organisms the area can support.

Question 7

Why is the productivity of the primary producers (autotrophs) is important in an ecosystem

Answer 7

The productivity of the primary producers (autotrophs) is important in an ecosystem since they provide the stored chemical energy to the other organisms.

Question 8

How fast the producers make food from the sun is known as

Answer 8

primary productivity

Question 9

primary productivity

Answer 9

the rate at which plants and other photosynthetic organisms produce organic compounds

Question 10

Gross primary productivity (GPP

Answer 10

is the total amount of material that is produced during photosynthesis; (GPP) the amount of organic, carbon-based material that is produced by photosynthesis

Question 11

Gross primary productivity is also thought of as how much carbon is used by the plants during respiration and is measured in

Answer 11

J/m2/day

Question 12

Organisms will need to use some of this energy for their own life processes such as respiration, moving, or reproducing. The remaining energy is the

Answer 12

net primary productivity (NPP

Question 13

net primary productivity

Answer 13

(NPP) the measure of the amount of organic material produced minus the amount of organic material used during life processes such as respiration; Net primary productivity is the amount of energy that is available to the organism that consumes it. The amount of organic material used by the autotroph during life processes, such as respiration, is subtracted from the GPP.

Question 14

What is another thing NPP measures

Answer 14

NPP also measures how effectively each trophic level uses and incorporates the energy from its food and into biomass.

Question 15

To find the net primary productivity of the ecosystem, the following equation is used:

Answer 15

GPP−respiration (carbon dioxide)=NPP

Question 16

An example of calculating for NPP would be a forest that has a GPP of 200 J/m2/day and 100 J/m2/day worth of carbon dioxide is used during cellular respiration.

Answer 16

Using the equation GPP−respiration (carbon dioxide)=NPP
200 J/m2/day−100 J/m2/day=100 J/m2/day

NPP would equal 100 J/m2/day

Question 17

What is often used to represent the percentage of energy entering an ecosysem

Answer 17

A pyramid is often used to represent the percentage of energy entering an ecosystem that is contained in biomass at different trophic levels. The pyramid represents the energy flow through the trophic levels.

Question 18

Consumers can only effectively use ?% of the energy stored in their food.

Answer 18

That 10% is used to help them grow, heal, move, and reproduce.

Question 19

Consumers can only effectively use 10% of the energy stored in their food. What happens the the remaninding 90%

Answer 19

The other 90% is released during digestion as heat or cannot be used and is transformed into waste.

Question 20

Because an organism can only use 10% of the energy in the food it eats, what happens the further you get from the producer of a food chain

Answer 20

Because an organism can only use 10% of the energy in the food it eats, the further you get from the producer of a food chain the less energy is being transferred to the next organism. Therefore, the levels of the energy pyramid get smaller and smaller as you move up the pyramid.

Question 21

How do scientists calculate the net primary productivity, or the amount of organic material available to transfer to the next trophic level?

Answer 21

Scientists can use the gross primary productivity, or the total amount of organic material produced through photosynthesis, and subtract the organic material that is used for life processes such as respiration.

Question 22

Calculate the net primary productivity of an ecosystem that has a gross primary productivity of 50060 J/m2/day
and the respiration is 36922 J/m2/day

Answer 22

13,138 J/m2/day

Question 23

Explain biomass and provide an example.

Answer 23

Biomass is the amount of organisms in an ecosystem; examples include wood chips.

Question 24

What stored energy is released when wood chips are burned?

Answer 24

The stored energy is released as heat when wood chips are burned.

Question 25

Why is there less energy as you move up the biomass pyramid?

Answer 25

There is less energy as you move up the biomass pyramid because only about 10 percent of energy is transferred to the next trophic level.

Question 26

Biomass as a source of renewabale energy

Answer 26

Biomass energy from plants and animals is potentially a great source of renewable energy and could someday lessen our dependence on fossil fuels. There are many different sources of biomass such as corn and other plants that can be fermented to produce ethanol. Ethanol can currently be found at some gas stations as “flex fuel” that is used by flexible fuel vehicles that can run on a mix of gasoline and ethanol (up to 83% concentration)

Question 27

Methane as fuel

Answer 27

Methane gas can be harnessed from animal waste and landfills of garbage that is discarded every day.

Question 28

Drawbacks of suing biomass energy

Answer 28

Burning biomass releases carbon dioxide into the atmosphere. When trees are cut and burned, more carbon may be released than plants can absorb. Cutting down trees (deforestation) has damaged many ecosystems along with the communities that rely on them.

Question 29

Drawbacks of ethanol

Answer 29

the combustion of ethanol is incomplete, and this produces black carbon that is known to increase climate change. Ethanol is a current additive to gasoline for vehicles and is advertised to help reduce our reliance on fossil fuels. Ethanol can also cause damage to engines in vehicles over time.

Question 30

Drawbacks of biofuels on food sources

Answer 30

Lastly, biofuels use plants and animals as an energy source that otherwise might be used for other applications such as a food source. Even if the plants were planted only for biofuel use, they still take up land space that could have been used for food crops. As the world population grows, the issue of having space not only for shelters but also space available for planting food crops also grows.

Question 31

There are some things that scientists must consider when using biomass. Some of the food that may have been used to feed people may be used for fuel instead while transporting biomass is expensive and combustion of ethanol produces black carbon, which is linked to global warming.

What are some of the disadvantages of using biomass?

Answer 31

Disadvantages of using biomass include releasing carbon dioxide, cutting down trees, and using food for fuel. Transporting the materials is expensive and using ethanol can add to global warming.