Earth's life support systems

Question 1

Atmospheric maintenance

Answer 1

photosynthetic organisms absorb CO2 and release O2 sustaining life on earth

Question 2

Role of plants in the hydrological cycle

Answer 2

Plants increase humidity via transpiration, which increases rainfall downwind

Question 3

Soil formation and conservation

Answer 3

Organism dies, gets broken down by detritivores then decomposers, releasing nutrients so new organisms can live
Plant roots protect the soil, binding it together so there’s less soil erosion from wind and water

Question 4

Food supplies

Answer 4

Organism eats food, organism becomes food.

Sick and weak die first= natural selection

Question 5

Pollination

Answer 5

Insects, birds, bats transfer pollen more reliably than wind

Question 6

Seed dispersal

Answer 6

Wind dispersal is unreliable, so using animals ensures better survival of plants and thus more animals

Question 7

Habitat provision

Answer 7

Plants provide habitat for animals (birds nesting in trees)