Chapter 32.1- Growth and nutrition

Question 1

What are the two ways in which fungi consuming food, cause problems?

Answer 1

Fungi absorb organic molecules directly through their cell walls.
1.They are too big to enter cell wall. There are bigger molecules that have to be broken down first by enzymes.

2. The ability to find food.

Question 2

What are Hyphaes?

Answer 2

they are thin hairs that provide fungi with more SA to get more nutrients into the cell

Question 3

What are mycelium?

Answer 3

The network of branching hyphaes that form the roots of the fungi

Question 4

Why is Hyphal growth?

Answer 4

Hyphal helps to find and locate food for fungi by extending their tips.

Question 5

what are chitins? and why are they important to Hyphal growth?

Answer 5

Chitins are modified polysaccharides that are made up of nitrogen. They are important because they make up the cell wall

Question 6

Why are cell walls important to hyphal? growth?

Answer 6

• prevents hyphal from swelling or breaking during osmosis
• the pressure of the tuphor within the cell wall pushes the hyphal tip further into the envoirment

Question 7

How does fungi transport materials through their hyphae?

Answer 7

increases and decreases of turgor pressure lets hyphae transport materials through bulk flow.

Question 8

What is a septum? Why is it important to fungi cells?

Answer 8

• walls that partially divide the cytoplasm into separate cells
• They are important to fungi cells because they the hyphae is damaged sealing mechanisms plug the pores from in the septa to stop more damage.

Question 9

What is yeast? How do they compensate for lacking hyphae?

Answer 9

• yeast are single-celled organisms in moist rich nutrients environments
• Yeast divide by budding off

Question 10

What advantages does fungi have over bacteria when finding food?

Answer 10

• fungi have growing hyphae that can actively always search for new food, and they can penetrate the side of food sources such as tree
• Bacteria flagella can only stretch out so far they have to wait for new food sources instead of moving

Question 11

Why are fungi considered an important plant decomposer?

Answer 11

• Fungi most common food source is cellulose (plant wall ) therefore they help to partially decay plants.

Question 12

What problems do fungi face when breaking down cellulose?

Answer 12

• individual cellulose polymers bind together closely making it hard to break down
• Woody tissues contain lignin which makes it harder to get to the cellulose.

Question 13

list some of the ways that fungi can infect plant cells

Answer 13

• using tugor pressure and hyphael to penetrate plant cell
• through plant wounds
  -through xylem vessels

Question 14

How do plants get infected above the ground?

Answer 14

through fungal pores carried by the wind or bodies of insects

Question 15

How do plants get infected below the ground?

Answer 15

through hyphae that penetrate the roots of plants.

Question 16

How do fungi infect insects intervertebras?

Answer 16

• they trap them using sticky traps on their hyphae
• ## other lasso their victims by forming rings

Question 17

What are mycorrhizal fungi? and what are the two different types?

Answer 17

they supply plant roots with nutrients from soil and get carbohydrates in return

ectomycorrhizal: the surround the plant but dont penetrate

endomycorrhizal : they penetrate the root providing a large surface area for nutrients exchange.

Endophytes: live within the leaves. they help benefit the cell when the cell is stressed

Question 18

Argue why lichens are symbioses between a fungus and a green alga/cyanobacteria.

Answer 18

• lichens can be separated to their individual part anf then reassembled
• the bulk of lichens is fungal hyphae
• photosynthetic algal cells form a thin layer under the surface of lichen