nutrient cycles

Question 1

producer

Answer 1

-autotrophs
-able to synthesis complex organic substances

Question 2

consumer

Answer 2

-heterotrophs
-unable to synthesis complex organic substances

Question 3

decomposers

Answer 3

-break down organic substances into simpler inorganic substances
-recycle nutrients

Question 4

biotic
abiotic environment

Answer 4

-living organisms
-non-living factors: soil factor, climate factor
topographical factor

Question 5

removing CO2 from atmosphere

Answer 5

-forests as carbon sinks: absorbs carbon dioxide through photosynthesis
-oceans as carbon sinks:
carbon dioxide dissolving into ocean/sea. remain/converts to carbonate and bicarbonate. carbon dioxide used by marine plants to photosynthesis.

Question 6

returning CO2 to atmosphere

Answer 6

respiration, decomposition, combustion

Question 7

passing carbon from one organism to the other

Answer 7

carbon in food enters food chain through feeding.

Question 8

eutrophication

Answer 8

-excess nutrients enter waterbodies by rainwaters
-algae absorbs and grows rapidly. This is an algae bloom.
-forms a blanket on surface of water, blocking sunlight from entering the water
-aquatic plants and submerged algae cannot photosynthesis without light, they die
-bacteria decomposes the dead plants and algae, multiplies rapidly, uses up oxygen in water, other organisms die.

Question 9

inorganic waste and insecticides

Answer 9

-factories dump inorganic waste which contains poisonous metal into water bodies.
-insecticides are carried by rainwater into water bodies.
-they accumulate in tissue of organisms and are not excreted. This is called bioaccumulation.
-they are passed along food chain through feeding, increases in concentration. This is called biomagnification.

Question 10

plastic pollution

Answer 10

-plastics are non-biodegradable
-animals eat/become caught.
-plastic releases toxins that affect marine animals. when broken down into very small particles, they are ingested by animals, enter food chain, leading to bioaccumulation and biomagnification.

Question 11

greenhouse effect+global warming

Answer 11

-high level of greenhouse gases in atmosphere
-industrial revolution, coal burnt, produces a lot of carbon dioxide
-CO2 increase rapidly
-causes global warming: earth temp increases, causes climate change like glaciers melt and raising in sea level, risk of flooding. unpredictable extreme weather, higher chance of extinction of animals.