ecosystems and material cycles

Question 1

what is parasitism?

Answer 1

where a species benefits at the expense of another species

Question 2

what is mutualism?

Answer 2

where a species benefits and provides for another species

Question 3

how would you use a quadrant to estimate the number of flowers in a 10m x 10m field?

Answer 3

• divide the field into 100 1m x 1m squares
• get a random number generator to pick a number
• take the quadrant and place it in the square
• count the number of flowers in the square
• repeat with different squares 5 times and find an average
• multiply by 100 to find the average number of flowers on the field

Question 4

how do you calculate the efficiency of biomass transfers?

Answer 4

efficiency of biomass transfers= biomass transferred to the next level/ biomass on previous level x 100

Question 5

what are 3 positives and negatives to human interactions with ecosystems?

Answer 5

positives:
- raise awareness to the public
- afforestation and can regrow destroyed things
- stop humans from doing certain things that damage the environment

negatives:
- release greenhouse gases to the atmosphere
- deforestation to build things on it
- overfishing

Question 6

what is food security?

Answer 6

having enough food to feed the population

Question 7

what are 3 factors that affect food security?

Answer 7

• increase birth rate
• conflict in some countries
• climate change

Question 8

what is the process of the carbon cycle?

Answer 8

co2 is removed from the air through photosynthesis and these plants are eaten by animals, when they die, they decompose and the carbon is released into the atmosphere again through burning fossil fuels

Question 9

what is compost and what does it do?

Answer 9

the decaying of biological material, used by farmers as natural fertilisers

Question 10

what conditions are needed for decay

Answer 10

more oxygen available for aerobic respiration which produces heat, the higher the temperature the higher the rate of decay so compost is made quicker

Question 11

what is the water cycle?

Answer 11

suns energy causes water to evaporate from the seas to make water vapour which is also formed from transpiration, water vapour rises, cools, condenses to form clouds then it precipitates on land and sea and the process repeats

Question 12

what is nitrogen often used for?

Answer 12

included in fertilisers to form ammonium nitrate to stimulate growth

Question 13

how can we tell if water is polluted?

Answer 13

the presence of bloodworms and sludgeworms

Question 14

how do we know if water is clean?

Answer 14

the presence of freshwater shrimps and stonefly

Question 15

how do we know if an area is less polluted?

Answer 15

rose blackspot fungus
lichen

Question 16

how does temperature affect the rate of decomposition?

Answer 16

the rate will increase when the temperature increases, but if it gets too hot the enzyme will denature and decomposition will stop

Question 17

how does water affect the rate of decomposition?

Answer 17

the more water, the faster the rate of reaction

Question 18

how does availability of oxygen affect the rate of decomposition?

Answer 18

the more oxygen, the higher the rate of decomposition as it is needed for aerobic respiration