2.2 Communities and Ecosystems

Question 1

Define Ecosystem

Answer 1

A community of interdependent organisms and their abiotic environment.

Question 1

Define Community

Answer 1

A group of populations living and interacting in the same area.

Question 2

Define Photosynthesis

Answer 2

The process by which green plants make their own food using water and carbon dioxide.

Question 3

Define Respiration

Answer 3

The process in which food, often in the form of glucose, is broken down to release the energy it contains.

Question 4

State the formula of Photosynthesis

Answer 4

Carbon Dioxide + Water –> Sugar + Oxygen

Question 5

State the formula of Cellular Respiration

Answer 5

Glucose + Oxygen –> Carbon Dioxide + Water + ATP

Question 6

Define a Producer

Answer 6

An organism that converts light energy into chemical energy. Examples include green plants, algae, etc.

Question 7

Define Photo - Autotrophs

Answer 7

Make their own food from carbon dioxide and water using the energy from sunlight, ex. green plants.

Question 8

Define Chemosynthetic Organisms

Answer 8

Make their own food from simple compounds and do not require sunlight; ex. bacteria in the deep ocean.

Question 9

Define Consumer

Answer 9

An organism that feeds on other organisms. Includes herbivores, carnivores, and omnivores.

Question 10

Define Decomposers

Answer 10

Organisms that feed on dead material and recycle nutrients in the ecosystem.

Question 11

Define Biomass

Answer 11

The amount of biological matter in a living or recently living organism, measured in units of mass per unit area (e.g. gm^-2).

Question 12

Define Trophic Level

Answer 12

The position that an organism occupies in a food chain as a result of its feeding habits. The term also defines the position of a group of organisms that feed at the same position in their food chain.

Question 13

Define Ecological Pyramids

Answer 13

Graphical models of the quantitative differences between amounts of living material stored at each trophic level of a food chain. Are measured for a given area at a given time.

Question 14

Define the Pyramid of Numbers

Answer 14

Shows the number of organisms at each trophic level in a food chain at one time. Units are number per unit area.

Question 15

Define the Pyramid of Biomass

Answer 15

Contains the biomass (mass of each individual x number of individuals) at each trophic level. Biomass is the quantity of dry organic material at any level of ecological organization. Units are mass per unit area (g/m^2) or joules per unit area (J/m^2).

Question 16

Define the Pyramid of Productivity

Answer 16

Shows the rate of flow energy or biomass through each trophic level. Shows energy / biomass being generated and available as food to the next trophic level during a fixed period of time.

Question 17

Define Non - Biodegradable

Answer 17

Pollutants that cannot be broken down within an organism or trophic level.

Question 18

Define Bioaccumulation

Answer 18

The build - up of a persistent pollutant within an organism or trophic level because it is not biodegradable.

Question 19

Define Biomagnification

Answer 19

The increase in concentration of persistent pollutants along a food chain.