Ecology Terms

Question 1

Ecosystem

Answer 1

Community of organisms (biotic) and non-living (abiotic) components of an area and their interactions .

Question 2

Primary productivity

Answer 2

The rate of primary production; energy fixed by photosynthesis in a given area in a given period of time. (KJ ha- 1 year-1)

Question 3

Producer

Answer 3

Photosynthetic organism at the start of the food chain that manufactures biomass (using light energy, carbon dioxide, water and lineal ions) for all living things.

Question 4

Secondary productivity

Answer 4

The rate of secondary production; the rate at which animals convert the chemical energy in plants that eat to their own biomass in a given area in a given period of time (Kj ha- 1 year-1).

Question 5

Trophic level

Answer 5

Position of an organism on a food chain

Question 6

Photosynthesis

Answer 6

A complex metabolic pathway that consists of three main stages: capturing light energy, light dependant reaction, light-independent reaction.

Question 7

Net production of consumers (N)

Answer 7

Calculated by subtracting the chemical energy lost due to respiration (R) and as a result of excretion and egestion (F) from the chemical energy stored in ingested food (I). N= I - (F+R)

Question 8

Net primary production (NPP)

Answer 8

The chemical energy store that remains when energy losses due to respiration are subtracted from the total energy store. This is used in plant growth or reproduction and is also available to other trophic levels. Net primary production (NPP) = gross primary production (GPP) - respiratory losses (R).

Question 9

Gross primary production (GPP)

Answer 9

Total amount of chemical energy stored in plant biomass in a set area or volume.

Question 10

Food chain

Answer 10

Describes the feeding relationships between organisms and the resultant stages of biomass transfer. It takes the form

Producer—> primary consumer—> secondary consumer—> tertiary consumer

Question 11

Food web

Answer 11

The interconnection of many different food chains in a habitat.

Question 12

Consumers

Answer 12

Organisms that feed off of other organisms to obtain energy

Question 13

Efficiency of energy transfer.

Answer 13

Efficiency of energy transfer between trophic levels is calculated using:

Percentage efficiency= energy available after transfer/ energy available before transfer x 100

Question 14

Biomass

Answer 14

The total mass of organic material, measured in a specific area over a set time
period. This can be calculated in terms of dry mass or mass of carbon per given area.

Question 15

Calorimitry

Answer 15

Technique used to estimate the chemical energy store in dry biomass.

Question 16

Aerobic respiration

Answer 16

A form of cellular respiration that takes place in the presence of oxygen
and produces carbon dioxide, water and ATP, It involves four main stages: glycolysis, link
reaction, Krebs cycle, and oxidative phosphorylation.

Question 17

Saprobionts

Answer 17

Microorganisms that break down dead plant and animal material into simpler
organic matter to obtain nutrients. Also known as saprophytes.

Question 18

Mycorrhizae

Answer 18

Mutualistic associations between some species of fungi and the roots of many
plants that retain water and minerals around the roots.

Question 19

Herbivores

Answer 19

Animals that eat plants, also known as primary consumers.

Question 20

Carnivores

Answer 20

Animals that prey on and eat other animals. They can be secondary or tertiary
consumers.

Question 21

Predator

Answer 21

an organism that actively hunts and kills another living organism for nutrition

Question 22

Prey

Answer 22

A living organisms eaten by predators

Question 23

Symbiotic relationships;

Answer 23

mutualism,
commensalism,
parasitism, and
competition.
Intraspecific
Interspecific