Ch 1 - Energy Transfer in the Biosphere

Question 1

1. How does energy enter the Biosphere?
2. How does energy move through the Biosphere?

Answer 1

1. Photosynthesis: producers turning sunlight into food energy.
2. Cellular respiration: Organisms turn food into energy.

Question 2

1. what consumer/heterotroph eats dead organisms, but do not kill its own food? e.g. hyena, eagle.
2. What consumer breaks down organic matter? e.g. fungi, earth worms.

Answer 2

1. Scavenger
2. Decomposer

Question 3

1. How much of the sun’s energy is absorbed by the atmosphere?
2. How much of the sun’s energy is absorbed by Earth’s surface?
3. How much is reflected? (albedo)
4. How much is used by producers?

Answer 3

1. 19%
2. 51%
3. 30%
4. 1-2%

Question 4

• What do food chains represent?
• What are the consumer and tropic levels?

Answer 4

• Represent energy movement through an ecosystem. (arrows point in direction energy is moving).

1° = primary
2° = secondary
3° = tertiary
4° = quaternary

Question 5

The first and second law of thermodynamics

Answer 5

1. Energy cannot be created or destroyed, only converted. (higher levels will never have more energy than lower levels).
2. For every energy conversion, waste energy is lost. (energy available to each level is less than the one before).

Question 6

Rule of 10

Answer 6

Each level in a food chain only get 10% of the energy available to the previous level.
The prey gives 10% energy to predator.

90% used for reproduction, movement, growth, development, heat.

Question 7

What is the rate of energy as the food chain goes up?

Answer 7

Energy decreases as the food chain goes up.
Example: 100% -> 10% -> 1% -> 0.1, etc.

*Omnivores emerge; diversifying food sources to make up for energy loss.

Question 8

What are food webs?

Answer 8

Linked food chains that show relationships throughout an ecosystem.

*show the effects of adding/removing organisms on the rest of ecosystem.

Question 9

Energy Pyramid

Answer 9

Producers to 4° and above.
(Least energy to more energy)

Question 10

Can an energy pyramid be flipped?

Answer 10

No because the laws of Thermodynamics says that energy can’t increase.

*most energy is available to producers so they will always be at the base. (ex: plants)

Question 11

Biomass pyramid

Answer 11

The total mass of all living things.
Example: the mass of all organisms in one trophic level.

Question 12

Numbers pyramid

Answer 12

The population size as an average for each level in an ecosystem.
For example: 1,500,000 grass -> 200,000 mice -> 90,000 snakes -> 1 hawk.

Question 13

Biomass pyramid (Exception)

Answer 13

Exception occurs when the producers can replace lost mass easily.
*occurs at lowest level.

Question 14

Numbers pyramid (Exception)

Answer 14

1 large producer can support many consumers.
*only occurs at producer level.

Question 15

Bioaccumulation

Answer 15

Build-up of persistent, harmful substances within tissues of specific organisms.

Question 16

Biomagnification

Answer 16

Levels of a contaminant increase in each level of a food chain.
*upside down pyramid 🔻