Rest of the flashcards

Question 1

What breaks down organisms for decomposition

Answer 1

Saprophytic bacteria and fungi

Question 2

What do Saprophytic bacteria and fungi need

Answer 2

Need water, certain temperatures and oxygen

Question 3

How does Saprophytic bacteria and fungi cause Decomposition

Answer 3

They secrete enzymes called Extracellular enzymes which break down the molecules

Question 4

What is nitrogen fixing bacteria

Answer 4

Role
Turn nitrogen gas from the air intro nitrates in the soil

Preferred soil condition
Aerobic

Question 5

What is Nitrifying Bacteria

Answer 5

Turns ammonia in the soil into nitrates

Preferred soil condition
Aerobic

Question 6

What is denitrifying Bacteria

Answer 6

Turns nitrates in the soil into nitrogen gas in the air

Preferred soil condition
Waterlogged (anaerobic soils)

Question 7

How are root hair cells adapted for their function

Answer 7

Each having an extension called root hair, on one side of each cell. This extension increases the surface are for the uptake of water and nitrates

Question 8

What is active uptake and transport

Answer 8

Minerals move from low concentration in the soil to a high concentration in root hair cells. This is against a concentration gradient and this process requires energy. The root hair cells carry out respiration to provide them with the energy to enable them to take up the nitrates. Root hair cells need oxygen

Question 9

What is eutrophication steps

Answer 9

1. Excess nitrates enter a lake or river
2. aquatic plants and algae grow due to nitrates
3. Plants and algae grow so much they use up all the nitrates (nitrate depletion) Algae covering water can cause shading of other plants
4. Plants and algae die
5. Plants and algae decomposed by microorganisms (bacteria + fungi)
   6 Microorganisms use up oxygen when they decompose the plants and algae
   7 Oxygen levels in the water drop
   8 Invertebrates and other animals in the water die due to lack of water
   9 Over time oxygenlevels inwater return to normal

Question 10

What is the definition of Eutrophication

Answer 10

Nitrates from fertilisers or sewage enter a lake or a river, they cause a process called eutrophication. Results in a lack of oxygen in water and kill invertebrates and other animals in water

Question 11

What is phototropism?

Answer 11

Plant responds to unidirectional light (e.g. plant on a windowsill) Plant shoot bends towards light