L6 - The chemical enviroment

Question 1

How do legumes ‘fix’ nitrogen?

Answer 1

|Through their mutualistic relationship with nitrogen fixing bacteria in their root nodules

Question 2

give 2 ways in which plants change to capture a resourse?

Answer 2

Grow towards the source, the source moves towards them

Question 3

What kind of resource causes wide resource depletion zones?`

Answer 3

A mobile resource such as nitrogen in a field. RDZ is widespread as depletion zones overlap

Question 4

What kind of resource causes narrow resource depletion zones?

Answer 4

Non-mobile resource such as phosphorous which is bound in soil colloids. RDZs don’t overlap

Question 5

What does overlapping resource depletion zones cause in plant roots?

Answer 5

competition between roots

Question 6

What are the 3 types of heterotrophs based on their method of gaining resources/food?

Answer 6

Parasite - eat living without killing
Predator - eat living by killing prey
Decomposer - eat already dead

Question 7

What is the nutritional advantage of being a carnivore against being a herbivore?

Answer 7

plant material has 40:1 C:N ratio while

meat has a 10:1 C:N and is high in lipid and protein

Question 8

Give an example of an organism with cellulases

Answer 8

Many fungi and some protozoa