topic 3

Question 1

What is an ecosystem?

Answer 1

interaction between living components and non-living components

Question 2

State the factors that plants may
compete for

Answer 2

● Light
● Space
● Water
● Mineral ions from soil

Question 3

State the factors that animals might
compete for.

Answer 3

● Food
● Mates
● Territory

Question 4

What is interdependence?

Answer 4

Different species in a ecosystem depend
on each other for various resources, if
one species is removed, the whole
community may be affected.

Question 5

State the abiotic factors that may affect an ecosystem.

Answer 5

● Light intensity
● Temperature
● Moisture
● Soil pH and mineral content

Question 6

what are the types of adaptation

Answer 6

structural - physical
behavioural - how they behave
functional - inable them to survive

Question 7

Give 3 examples of extreme living environments

Answer 7

● High temperature
● High pressure
● High salt concentration

Question 8

carbon water cycle

Answer 8

takes carbon out - photosynthesis
dissolved in oceans - takes carbon out
respiration - puts carbon in
combustion - puts carbon

Question 9

whats percolation

Answer 9

water travelling through rocks to underground water

Question 10

factors affecting the rate of decay

Answer 10

water
temperature
oxygen

Question 11

adavntages of decay

Answer 11

garderners and farmers
optinum conditions of decay
to produce compost
natural fertilizer
crop production

Question 12

what does anerobic decay produce

Answer 12

methane

Question 13

why is watse management produced

Answer 13

increase in population
more reasources
more waste produced
more pollution

Question 14

different types of waste management

Answer 14

water - sewage fertilizer toxic chemials
air smoke and scidic gases

Question 15

ways to maintain biodiversity

Answer 15

breeding programmes
protection of rare habitats
seed banks
shooting ilegal

Question 16

What is trophic level 1?

Answer 16

Plants and algae which make their own
food

Question 17

What is trophic level 2?

Answer 17

Herbivores which eat producers - called
primary consumers.

Question 18

What is trophic level 3?

Answer 18

Carnivores that eat herbivores - called
secondary consumers.

Question 19

What is trophic level 4?

Answer 19

Carnivores that eat other carnivores -
called tertiary consumers.

Question 20

How do decomposers break down dead matter?

Answer 20

Decomposers release enzymes which
catalyse the breakdown of dead material into
smaller molecules. Soluble small food
molecules then diffuse into the
microorganisms.

Question 21

What is biomass?

Answer 21

The dry mass of all of the living
organisms in an area

Question 22

What percentage of the incident energy
from light for photosynthesis do
producers transfer?

Answer 22

1%

Question 23

What percentage of the biomass from
one trophic level is transferred to the
level above it in feeding?

Answer 23

Approximately 10%

Question 24

Why are biomass transfers not 100%
efficient?

Answer 24

• Egestion (removal of faeces)
• Excretion (removal of waste products e.g. urine
  containing urea and water)
• Respiration (loss of carbon dioxide and water) in which
  large amounts of glucose are used
• The production of inedible bones and shells

Question 25

How does the efficiency of biomass
transfers affect the number of trophic
levels in a biomass pyramid?

Answer 25

The less efficient the transfers, the fewer trophic levels and the fewer organisms in higher trophic levels.

Question 26

What is a biomass pyramid?

Answer 26

A pyramid that shows the total dry mass of organisms at each trophic level
Trophic level 1 is at the bottom of the
pyramid

Question 27

What is a pyramid of numbers?

Answer 27

A pyramid of numbers shows the number
of organisms at each trophic level

Question 28

State the biological factors threatening
food security.

Answer 28

● Rising birth rates
● Changing diets in developed countries → food is transported around the world
● New pests and pathogens
● Environmental changes affecting food production
● Increased cost of agriculture
● Armed conflicts

Question 29

How does intensive farming increase the
production of animals?

Answer 29

● Feed animals high protein foods to increase growth.
● Reduce their energy loss to the environment:
○ Limiting movement
○ Regulating their surrounding temperature
● Feed animals antibiotics to prevent diseases.

Question 30

What are the advantages of intensive
farming?

Answer 30

● Higher yield of food
● More efficient
● Allows easier quality control

Question 31

What are the disadvantages of intensive
farming?

Answer 31

● May lead to antibiotic resistance.
● Cost is high.
● Ethical objections eg. limiting movement of
animals may cause them harm.
● Biodiversity may be reduced.

Question 32

How can fish stocks be conserved?

Answer 32

● Control the size of gaps in fishing nets to
prevent juvenile fish from being killed.
before reaching reproductive maturity
● Introduce fishing quotas

Question 33

What is a transgenic organism?

Answer 33

An organism that has been genetically
modified to contain genetic material from
another source

Question 34

State an example of genetically modified
foods.

Answer 34

GOLDEN RICE

Question 35

How might crops be genetically
modified?

Answer 35

● To improve nutritional value
● To be pest resistant
● To be pesticide resistant

Question 36

WHAT IS BIOTECHNOLOGY

Answer 36

solutions to food security
to meet human demand

Question 37

how is quorn produced

Answer 37

fungus grown on glucose syrup
requires areobic conditions
biomass is harvisted and purified