Organisms & Their Environment, Human Influences on Ecosystems, Biotechnology & Genetic Modification

Question 1

How is energy allocated in an organism [2]

Answer 1

1) 10% of energy is stored in the organism as biomass
2) 90% of energy is lost through egestion, excretion, and respiration

Question 2

Producers define

Answer 2

Organisms that make their own organic nutrients from sunlight using photosynthesis

Question 3

Define consumer

Answer 3

Organisms that get their energy by consuming another organism

Question 4

Rank of consumer

Answer 4

Primary -> Secondary -> tertiary -> Quaternary

Question 5

How does the arrow point in the food chain?

Answer 5

From nutrient source to predator

Question 6

Food webs vs food chain

Answer 6

Food webs shows all food chains within an ecosystem and all of the possible ways the energy could be transferred

Question 7

Food pyramids use

Answer 7

Tell us the population numbers of different trophic levels. It does not always have to be pyramid shaped

Question 8

Food pyramids of biomass [2]

Answer 8

1) Measure the differences in the total proportion of mass between different trophic levels
2) Always pyramid shape, as it accounts for size of organism

Question 9

How much energy is passed from one trophic level to the next as biomass

Answer 9

10%

Question 10

Ways energy is lost

Answer 10

waste, respiration, maintaining body temperature etc

Question 11

Why are pyramids of energy preferred over pyramids of number [2]

Answer 11

1) Pyramids of number does not account for life span or size
2) Pyramids of biomass account for different sizes, lifespans, and different types of biomass have different energy requirements

Question 12

Why does the farmer rather farm seaweed than salmon [3]

Answer 12

1) Seaweed is at lower trophic level
2) Energy is lost between trophic levels (10% transfer)
3) Energy lost in respiration, heat, and movement

Question 13

Explain how some mammals are able to stay in cold water for a long time compared to a reptile. [5]

Answer 13

1) Vasoconstriction will redirect blood away into vital organs
2) Fur and fat under skin
3) Poor conductor of heat
4) Generate heat by shivering
5) Fats help insulate the body

Question 14

Risks of untreated sewage to marine ecosystems [2]

Answer 14

1) Negative impacts and can lead to eutrophication of water
2) This eventually creates an oxygen-deprived environment where very little can survive

Question 15

Steps of eutrophication [6]

Answer 15

1) Excessive nutrients from fertilisers run off from land into water
2) Aquatic plants flourish and grow rapidly
3) Algae also show rapid growth
4) Algae bloom prevents sunlight from reaching aquatic plants, water oxygen levels fall
5) Decomposition rate increases, aerobic respiration of decomposers reduces dissolved oxygen further
6) Death of organisms requiring dissolved oxygen in water (Anoxic environment = no oxygen in water)

Question 16

Plastic pollution - Oceans [3]

Answer 16

1) Animals can eat plastics and become caught in it
2) Plastics can release toxins in to the water
3) Small microplastics can be ingested by marine organisms and enter the food chain

Question 17

Plastic pollution - land [2]

Answer 17

1) Buried in landfills
2) Toxins in plastic leech in to the soil, making it unfit for growing crops or livestock

Question 18

Air pollution - greenhouse gases [2]

Answer 18

1) Humans are responsible for elevated levels of carbon dioxide and methane in the atmosphere
2) leads of global warming and climate change