Cycles

Question 1

Describe the carbon cycle

Answer 1

1. Green plants use CO2 to make carbs, fats and proteins
2. Eating passes carbon compounds from plants to animals
3. Respiration cause CO2 back into the air
4. Useful products (fossil fuels) are burned and releases CO2 back into the air

Question 2

Two examples of nitrogen fixation

Answer 2

1. Lighting: amount of energy is enough to make nitrogen react with oxygen to form nitrates
2. Nitrogen-fixing bacteria: atmospheric N2 to nitrogen compounds

Question 3

Four types of bacteria in nitrogen cycle and their uses

Answer 3

1. Decomposers: breaks down proteins and urea and turns it into ammonia
2. Nitrifying bacteria: ammonia to nitrates
3. Nitrogen fixing bacteria: atmospheric N2 to nitrogen compounds
4. Denitrifying bacteria: nitrates to N2 gas

Question 4

Describe the water cycle

Answer 4

1. Water from sea evaporates into water vapour
2. Water vapour is carried upwards, cools and condenses to form clouds
3. Water falls from clouds as precipitation and is returned to land/sea