4.1 Ecology Study Guide

Question 1

Define Biomass.

Answer 1

The total mass of living matter in a given area or volume

Biomass is often used as a measure of the amount of organic material available for energy production.

Question 2

Define Productivity.

Answer 2

The rate at which energy is converted by photosynthetic and chemosynthetic autotrophs to organic substances

Productivity is typically measured in terms of biomass produced per unit area over a specific time period.

Question 3

Define Efficiency.

Answer 3

The ratio of useful output to total input

In ecological terms, it often refers to how effectively energy is transferred from one trophic level to the next.

Question 4

What are the inputs and outputs of Photosynthesis?

Answer 4

Inputs: Carbon dioxide, Water, Light energy
Outputs: Glucose, Oxygen

Photosynthesis occurs in plants, algae, and some bacteria.

Question 5

What are the inputs and outputs of Respiration?

Answer 5

Inputs: Glucose, Oxygen
Outputs: Carbon dioxide, Water, Energy (ATP)

Respiration occurs in all living organisms.

Question 6

What type of organisms perform the processes of photosynthesis and cellular respiration?

Answer 6

• Photosynthesis: Autotrophs (plants, algae, some bacteria)
• Cellular respiration: All organisms (including autotrophs and heterotrophs)

Autotrophs produce their own food, while heterotrophs consume other organisms.

Question 7

What is shown in a pyramid of energy vs. a pyramid of numbers vs. a pyramid of biomass?

Answer 7

• Pyramid of energy: Energy flow at each trophic level
• Pyramid of numbers: Number of organisms at each trophic level
• Pyramid of biomass: Total mass of organisms at each trophic level

Each pyramid illustrates different aspects of ecosystem structure and function.

Question 8

Apply the rule of 10 to an energy pyramid to determine the energy available at each trophic level.

Answer 8

Energy available decreases by 90% at each successive trophic level

For example, if the primary producers have 1000 units of energy, primary consumers would have 100 units.

Question 9

Explain why it is considered more efficient to eat at a lower trophic level vs. a higher trophic level.

Answer 9

Lower trophic levels have more available energy and biomass

Consuming plants (lower trophic level) is more efficient than consuming animals (higher trophic level) due to energy loss at each level.

Question 10

Predict how the amount of solar energy in a location relates to productivity.

Answer 10

Higher solar energy leads to higher productivity

Areas with abundant sunlight typically support more plant growth, resulting in greater biomass.

Question 11

Predict how the amount of solar energy in a location relates to biomass.

Answer 11

More solar energy results in increased biomass

Locations with higher solar energy can support more plant life, leading to greater overall biomass.