Bio 5: Ecosystems and sustainability

Question 1

Habitat

Answer 1

A place where an organism lives

Question 2

Population

Answer 2

All of the organisms of one species that live in the same place at the same time and that can breed together.

Question 3

Community

Answer 3

All the populations of different species that live in the same place at the same time.

Question 4

Ecosystems

Answer 4

A group of organisms including biotic factors and abiotic factors and their interrelationships between them.

Question 5

Niche

Answer 5

Role that a species plays in an ecosystem

Question 6

Producers

Answer 6

Autotrophic organisms that convert light energy into chemical energy, which is then supplied to consumers

Question 7

Consumers

Answer 7

Living organisms that feed on other living organism

Question 8

Trophic level

Answer 8

Level at which an organism feeds in a food chain

Question 9

Pyramids of biomass

Answer 9

Areas of the bars are proportional to the dry mass of all the organisms at the trophic level

Question 10

Pyramid of energy

Answer 10

Burning the organisms in a calorimeter and working out how much heat is released per gram.

Question 11

Gross primary productivity

Answer 11

Rate at which plants convert light energy into chemical energy.

Question 12

Net Primary Productivity

Answer 12

NPP= GPP - Respiration
Rate at which carbphydrates accumulate in the tissue of plants of an ecosystem.
kg/ha/yr

Question 13

Primary productivity

Answer 13

Total amount of energy fixed by photosynthesis.

Question 14

Succession

Answer 14

The directional change in a community over time

Question 15

Saprotrophs

Answer 15

Secrete enzymes onto dead and waste material, they digest the material into small molecules, which are then absorbed into the organisms body.

Question 16

Nitrogen fixation

Answer 16

Lightning strikes
Haber process
Nitrogen-fixing bacteria

Question 17

Nitrogen-fixing bacteria

Answer 17

Root nodules
Give fixed nitrogen, get carbon compounds
Anaerobic: reduce nitrogen gas to ammonium ions

Question 18

Nitrification

Answer 18

Get energy from oxidising ammonium ions to nitrite
Or nitrite to nitrate
Only in well aerated soils

Question 19

Denitrification

Answer 19

Nitrates back to N2

Anaerobic conditions: nitrate as source of oxygen, make N2 and N20

Question 20

Carrying capacity

Answer 20

Maximum population size that can be maintained over a period of time in a particular habitat

Question 21

Limiting factors

Answer 21

factors that cause the population of something to stop growing any larger

Question 22

Intraspecific competition

Answer 22

Competition between individuals of the same species.

Question 23

Interspecific competition

Answer 23

Competition between individuals of a different species

Question 24

Coppicing

Answer 24

Cutting a tree close to the ground,once cuts several new shoots will grow from the surface, and these will grow into stems. These can then be cut again.

Question 25

Pollarding

Answer 25

Cutting the trunk higher up, in order to stop deers from eating the new shoots

Question 26

Clear felling

Answer 26

Felling an entire area. This destroys on a large scale. It reduces soil minerals and leaves it susceptible to erosion.

Question 27

Conservation

Answer 27

Maintenance of biodiversity, habitats and ecosystems

Question 28

Conservation: reasons and methods

Answer 28

• Over exploitation for food
• Habitat disruption or fragmentation
• Invasive species
• Extinction
• Valuable source : food, medicine, etc
• Pollination
• Ecotourism
• Vaccinating against disease
• Control predators and poachers
• Preserve habitats