Genetics and ecosystems (Module 6)

Question 1

Producer

Answer 1

Green plants that convert simple molecules into complex organic molecules using the sun’s energy

Question 2

Consumer

Answer 2

Animal or plant that feeds on organic molecules made by a producer

Question 3

Decomposer

Answer 3

saprophytic bacteria and fungi that break down complex molecules in other organisms once they die, releasing simple molecules for other organisms to use

Question 4

Detritivore

Answer 4

Feed on particles or decaying organic matter, releasing the energy locked up in them to other living organisms

Question 5

Saprotrophs

Answer 5

Organisms such as bacteria and fungi that feed on dead and decaying matter

Question 6

Geochemical

Answer 6

From rocks and ocean deposits

Question 7

Eutrophication

Answer 7

Algae grow 
Light blocked out - kill bigger plants 
Bacteria decay dead plants
Bacteria use up all oxygen 
Fish die

Question 8

Ammonification

Answer 8

Production of ammonia from organic ammonium containing compounds such as ammonium nitrate, urea, proteins, nucleic acids and vitamins

Question 9

Nitrification

Answer 9

Oxidation of ammonium ions (NH4+) to nitrates (NO3-)
Two stage process
. Ammonia to nitrite
. Nitrite to nitrate

Question 10

Denitrification

Answer 10

Nitrate converted back to nitrogen gas
Occurs in water logged soils with little oxygen in anaerobic conditions
Leaves soils lacking in nutrients

Question 11

Nitrogen fixing

Answer 11

Conversion of atmospheric nitrogen in soils to nitrate or ammonium
. Lightning - nitrogen +oxygen = nitrates
. Haber Process - Nitrogen + hydrogen = ammonia
. Microorganisms - free living in soil, in mutualistic relationship in legumes

Question 12

Assimilation

Answer 12

When a molecule becomes part of an organism (nitrates become part of protein in plants)

Question 13

Leghaemoglobin

Answer 13

Molecule that absorbs oxygen in root nodules to make anaerobic conditions that allow nitrogen fixing

Question 14

Nitrogenase

Answer 14

Enzyme used in Rhizobium bacteria to convert nitrogen gas into ammonium ions, using ATP energy

Question 15

Nitrosommonas

Answer 15

Free living nitrifying bacteria - ammonium to nitrite

Question 16

Nitrobacter

Answer 16

Free living nitrifying bacteria - nitrite to nitrate

Question 17

Rhizobium

Answer 17

Nitrogen fixing mutualistic bacterium in legumes

Question 18

Abiotic factors

Answer 18

non-living components of an ecosystem that affect other living organisms

Question 19

Biotic factors

Answer 19

Environmental factors associated with living organisms in an ecosystem that affect each other (predation, disease)

Question 20

Ecosystem

Answer 20

Community of animals, plants and bacteria interrelated with the physical and chemical environment

Question 21

Biomass transfer

Answer 21

Transfer of biomass from one trophic level to another

Question 22

Trophic level

Answer 22

The level at which an organism feeds in a food chain

Question 23

Productivity

Answer 23

Rate of production of new biomass by producers

Question 24

Climax community

Answer 24

Final stable community that exists after succession has occurred

Question 25

Deflected succession

Answer 25

succession is stopped or interfered with (grazing, mowing)

Question 26

Pioneer species

Answer 26

The species that begin the succession process

Question 27

Succession

Answer 27

Progressive change in a community of organisms over time

Question 28

Population size of a species

Answer 28

mean number of individuals of the species in each quadrat / fraction of the total habitat area covered by a single quadrat