Fungi

Question 1

Features of fungi

Answer 1

Made of thread like structures called hyphae (mycelium)
Cell wall made of chitin

Question 2

Nutrition

Answer 2

Heterotrphic ;
Saphrophytes , acts as decomposers recycles nutrients back into environment
Parasites ; lives in or on a host causing harm to the host , population control

Question 3

Symbiosis

Answer 3

Two different species living together where at least one benefits

Question 4

Edible

Answer 4

Field mushroom , truffle

Question 5

Poisonous

Answer 5

Death cap , destroying angel

Question 6

Beneficial fungi

Answer 6

Ecomically ; source of food and makes yeast
Medical : production of Antibiotics

Question 7

Harmful

Answer 7

Economic: attack crops (blight)
Medical : infects animals (ringworm, athletes foot)

Question 8

Rhizopus (structure)

Answer 8

Black bread mould
Long thin threads called hyphae with place pins at ends inside pins is spores
No cross walls and are multi nucleate
The nuclei are all haploid
Three types of hyphae : Stolons Rhizoids Sporangiophores

Question 9

Columella

Answer 9

Separates spores from sporangiophore

Question 10

Sporangium

Answer 10

Produces and hold spores

Question 11

Spores

Answer 11

Used in asexual reproduction

Question 12

Stolon

Answer 12

Aerial hyphae growing horizontally, these spread over the surface , turning downward at intervals to create rhizoids

Question 13

Rhizoids

Answer 13

Branched hyphae that penetrate the food source anchoring the fungus
Release digestive enzymes into food and absorb digested food

Question 14

Sporangiophore

Answer 14

Hyphae branched up from stolon large at tip

Question 15

Rhizopus (digestion)

Answer 15

Lives on starchy food
Releases enzymes to substrate
Breaks down carbohydrate to maltose
Reabsorbed by diffusion
This process is extra cellular digestion

Question 16

Rhizopus ( reproduction)( asexual)

Answer 16

Asexually (sporulation)
1. Mitosis occurs in sporangium and produces haploid spores
2. Each cell develops a resistant wall and is now a spore
3. In dry conditions the sporangium dries out and bursts , releasing spores
4. If spore lands on suitable substrate they will germinate new mycelium forms

Question 17

Rhizopus (reproduction) ( sexually)

Answer 17

Under harsh conditions in order to survive
Structurally identical but chemically different positive and negative
1. Nuclei move into newly formed swellings - progametangia
2.cross - walls form to produce gametangia
3.wall between gametamgia break down
4. Fertilisation occurs when two nuclei fuse and become diploid
5. This forms a tough resistant wall called a zygospore (2n)
6. Parent hyphae dye away and zygospore is released
7. When conditions are suitable zygospore germinates by meiosis
8. Haploid hypha grows from zygospore and produces sporangium
9. Nuclei in the sporangium form spores by mitosis these spores are later dispersed

Question 18

Yeast (structure )

Answer 18

Unicellular
Oval or spherical
Haploid nucleus
Large central vacuole
Thin cell wall of chitin

Question 19

Yeast ( reproduction) (budding)

Answer 19

Asexual
1. Small bud grows out from the cell wall and fills with cytoplasm
2. Nucleus undergoes mitosis
3. One of the daughter nuclei move into bud
4. The bud enlarges and pinches off from the mother cell

Question 20

Advantages and disadvantages of budding

Answer 20

Rapid no variation ( genetically identical )

Can increase risk of disease

Question 21

Aseptic

Answer 21

Free from pathogens

Question 22

Sterility

Answer 22

Free from all microorganisms