ecosystems and human impact

Question 1

what is the source of all energy on the planet

Answer 1

sunlight

Question 2

is energy lost or gained at each stage of the food chain?

what does this do to the number of organisms that can exist at each level?

Answer 2

lost

they go down as the food chain progresses

Question 3

are plants producers

Answer 3

yes

Question 4

How is energy lost ?

Answer 4

organisms rarely eat all of another organism, so do not take all the energy available

Question 5

Give an example on how energy is used in the food chain

Answer 5

for repair of damaged cells and tissues. this needs energy from food.
for maintenance and growth of cells and organisms

Question 6

give an example of energy lost in the food chain

Answer 6

waste materials, carbon dioxide, urea and faeces all still contain energy!
respiration

Question 7

whats the equation for efficiency of energy tranfers between trophic levels

Answer 7

biomass transferred to the next trophic level divided by biomass available at previous trophic level. x100

Question 8

give an example of issues surrounding the need to balance the human requirements for food
and economic development with the needs of wildlife

Answer 8

people need places to live and work, but building houses, roads etc destroy habitat
the habitat may contain rare or endangered species

Question 9

define intensive farming

Answer 9

intensive farming is an agricultural system that aims to produce maximum yield from the land available.

Question 10

name 2 advantages of intensive farming

Answer 10

the food is cheaper to produce and more profitable to the farmer.
yield is high, more organisms can be kept and their conditions can be controlled

Question 11

name 2 disadvantages to intensive farming

Answer 11

chemicals used (pesticides and antibiotics) could enter the human chain.
causes stress and discomfort on animals, poor quality of life

Question 12

what is the indicator pollutant in air?

Answer 12

lichens

Question 13

what two compounds effect how lichens look in the air?

Answer 13

amount of sulpher dioxide and nitrous oxide

Question 14

in low or high levels of sulpher dioxide to we find leafy lichens?

Answer 14

low

Question 15

what are pesticides used for?

Answer 15

kill agricultural pests

Question 16

name two heavy metals

Answer 16

lead and mercury

Question 17

which organisms accumulate the highest level of poison

Answer 17

organisms at the top of the food chain

Question 18

what’s the first step in eutrophication

Answer 18

the fact that untreated sewage and fertilisers may run into water and cause
rapid growth of plants and algae