Organisms and Their Environment
259 questions· page 1 of 26
What is the principal source of energy in most biological systems?
Options
A bacteria
B photosynthesis
C respiration
D sunlight
Untreated sewage contains nitrates and phosphates.
What will happen in the lake if untreated sewage is added?
Options
A increased biodiversity
B increased eutrophication
C increased fish populations
D increased light penetration
DDT is an insecticide that is harmful to living organisms. It builds up in the cells of living organisms as it is not excreted.
The diagram shows the path taken by DDT when it enters a lake.
Which organisms would the DDT harm the most?
Options
A aquatic plants
B carnivorous fish
C herbivorous fish
D fish-eating birds
What is a food chain?
Options
A a diagram showing an organism getting its energy by feeding on other organisms
B a diagram showing an organism's diet
C a diagram showing the flow of energy through a chain of organisms
D a diagram showing the names of trophic levels
Soil that contains more water allows denitrifying bacteria to grow well.
Which effects will be seen on the growth of plants in this soil?
Options
A More nitrate ions are taken up by plants, so plants grow less well.
B More nitrogen fixation takes place, so plants grow taller.
C Denitrification results in nitrogen gas being taken up by plants and they grow taller.
D There are fewer nitrate ions in the soil, so plants grow less well.
The statements describe the process of eutrophication which may happen after excess nitrogen fertiliser runs from fields into streams.
They are not in the correct order.
- Bacteria decay dead plants and use up oxygen.
- Animals die or leave the area.
- Light cannot reach aquatic plants.
- The growth rate of algae increases.
- Aquatic plants die.
What is the correct order for these statements?
Options
A
B
C
D
The diagram shows a food web.
Which organisms in this food web are primary consumers?
Options
A insects
B plants
C small birds
D small mammals
The processes listed occur in living organisms in a food chain.
- excretion
- photosynthesis
- respiration
Which processes would result in a loss of energy from a food chain?
Options
A 1 and 2
B 1 and 3
C 2 only
D 3 only
Trees in a forest need a constant supply of nitrates to continue growing.
The diagram shows some of the stages of the nitrogen cycle that provide the necessary nitrates.
Which stage in this cycle is not brought about by living bacteria?
Options
A A
B B
C C
D D
What is a method of conserving fish stocks?
Options
A fishing in protected areas
B fishing with nets with a small mesh size
C having closed fishing seasons
D only catching young, immature fish