Topic 9 - Ecosystems And Material Cycles

Question 1

3 factors affecting the rate of decay ….

Answer 1

-temperature
-desiccation
-oxygen

Question 2

How does temperature affect decay / decomposition?

Answer 2

-cold temp slows decay down as it slows the reaction ( low energy reactions and therefore less successful collisions)

-too hot temp slows decay as decomposes denature

Question 3

What’s desiccation?
How does desiccation affect rate of decay / decomposition ?

Answer 3

Desiccation - removal of water / solvent ( extreme dryness)

-dessication removes the solvent and decay slows as organisms need water to survive and carry out chemical processes

Question 4

What are saprophytes ?what’s special about them?

Answer 4

Organisms that eat dead things eg- mushrooms

-they don’t have digestive systems , they liquify food outside the body and absorb it

Question 5

What’s a biotic factor?

Answer 5

Living

Question 6

What’s an abiotic factor!

Answer 6

Nonliving

Question 7

What’s a niche?

Answer 7

The role of a species within a community

Question 8

Abiotic factors effecting communities and how ?

Answer 8

1) light intensity - light is required for photosynthesis.rate of photosynthesis affects how much a plant rows .plants can be food sources and shelters for many organisms

2)temperature - temperature affects the rate of photosynthesis

3) moisture levels -both plants and animals need water to survive

4) soil ph and mineral content - soil ph affects the rate of decay and therefore how fast mineral ions return to the soil to be used again. Different species of plants thrive in different nutrient concentrations

5)wind intensity and direction - wind affects the rate of transpiration in plants. Transpiration effects the rate of photosynthesis’s in a plant as it transports water and minerals ions to the leaves

6)c02 levels