Fungi Flashcards
Is fungi eukaryotic or prokaryotic?
Eukaryotic
How do fungi reproduce?
Asexually and sexually by spores
What are fungi cell walls made up of?
Chitin
Fungi nutrition
Heterotrophs
Rhizopus - saprophyte of starchy foods
Give two types of fungi
Rhizopus and yeast
How does rhizopus reproduce sexually?
Hyphae grow closer from opposite strains
Swellings form opposite eachother and touch
Progametangia - nuclei move into swelling
Gametangia - cross walls form
Walls of game dissolve
Diploid zygote nuclei formed by fertilisation a
Zygote
Zygospore forms around these nuclei + remains dormant + when conditions good it germinates by meiosis
Haploid hypha grows out zygoslore and produced sporganium at tip
Releases spores
How do rhizopus reproduce asexually?
Sporangiophores grow upwards and form sporangia. Spores are formed by mitosis and released and dispersed by wind. Spores germinate to from new mycelia
Is rhizopus multicellular or single celled
Multicelled
Is yeast single celled or multicelled?
Single celled
How does yeast reproduce?
Budding
Parent cell divides by mitosis and one nucleus and cytoplasm enters small bud which may seperate or remain attached
New bud divides again - colony will form
What is the function of the hyphae?
Digest and absorb substrate
What is the function of the stolon?
Allows fungus to spread rapidly
What is the function of rhizoids?
Extra surface area for absorption
Digestion
Achorage
What does aseptate mean?
No cross walls
How does yeast respire?
Anaerobically
Benefits of fungi
Yeasts can produce alcohols such as beers and wines
Mushrooms can be grown as source of food
Used in baking to make dough rise
Disadvantages of fungi
Potato light fungus - destroyed potato
Bread mould
Diseases - athletes foot
Yeast structure contains
Cell wall, cytoplasm, food vacuoles, vacuole, nucleus
[two v, cytoplasm, cell wall, nucleus]
What is hypha?
Tube or filament in a fungus
What is mycelium?
Visible mass of hyphae
Give one advantage and one disadvantage of asexual reproduction in organisms such as yeast
Adv - rapid reproduction
Disadv - increased risk of disease [no variation]
How does the genetic make up of the new yeast cell in budding relate to the parent cell and explain why
Identical because it reproduced by mitosis which is simply the division of one cell into two
How can scientists distinguish between different viruses?
Type of nucleic acid
Shape [of protein coat]
What’s the method of asexual reproduction in rhizopus known as?
Sporulation
Give an example of a poisonous fungus
Death cap fungus
What is the role of fungi such as rhizopus in nature and why is it vital?
They are saprophytes - feed on dead organic matter
Vital - return nutrients back into the soil
Give one structural difference between Fungi and Plantae?
Cell wall -
Fungi - chitin
Plantae - cellulose
Fungi may be classified into two groups on the basis of their nutrition, what are they?
Parasitic
Saprophytic
DIAGRAM
[of reproducing yeast cell]
Budding diagram!!
Nucleus + cell
-The growth of leaf yeast in the lab-
What principal nutrient was added to the agar for the yeast?
Malt
-The growth of leaf yeast in the lab-
How did you introduce yeast into the Petri dish?
Sterilise forceps by heating it in the flame of a Bunsen burner and allow cool before using the forceps to pick up leaves. Attach leaves to lid using blue tac, and leave the dish upright for 24 hours
-The growth of leaf yeast in the lab-
What did the yeast look like when it had grown on the agar?
Pink colonies growing on surface of agar
Sexual reproduction in Rhizopus is normally triggered by an adverse environmental stimulus. Suggest one stimulus
Dehydration
Give two advantages of rhizopus of zygospore formation
Can survive drought
Dispersal
What happens to new cells formed in the process of budding?
They form a colony or break away from mother cell
How does asexual reproduction in Rhizopus differ from that in yeast?
Rhizopus - produces spores
Explain why sporulation is asexual?
Only one parent involved
No gametes involved
What does the term saprophytic mean?
Feeds on dead organic matter
Explain the importance of saprophytic nutrition in the overall scheme of nature
Breakdown of dead organic matter and returns nutrients into the soil to be recycled
Name another form of nutrition employed by some fungi
Parasitic
Give two examples of harmful members of the kingdom of Fungi
Death Cap mushroom - deadly poisonous
Puccinia - Black rust disease on wheat plant
Give two beneficial members of the kingdom of Fungi?
Penicillium
Yeast
Give a role for rhizoids and explain how they carry out this role
Digestion
Secretes enzymes
Name one structure in plant cells not found in fungi
Chloroplast
-The growth of leaf yeast in the lab-
What is the purpose of using agar when growing fungi or bacteria in the lab?
Source of nutrients
-The growth of leaf yeast in the lab-
Suggest one reason why leaf yeasts are more plentiful in July than in March
More leaves due to a more suitable temperature
-The growth of leaf yeast in the lab-
What was the precise purpose of the control in this investigation?
To show that the yeast did come from the leaf
-The growth of leaf yeast in the lab-
How did you recognise the leaf yeasts when they appeared on the agar?
Pink colonies
-The growth of leaf yeast in the lab-
How did you safely dispose of the plates at the end of the investigation?
Immerse in disinfectant [dettol]
-The growth of leaf yeast in the lab-
Draw a graph to show how the number of leaf yeasts varied following their introduction into the plate
Lag - stationary
Give one way in which Rhizopus differs from yeast
Multicellular
Rhizopus undergoes both sexual and asexual reproduction, yeast only asexual
What is a nutrient medium?
Solid Material that supplies food to allow for growth
-The growth of leaf yeast in the lab-
Name the nutrient medium you used
Malt agar
-The growth of leaf yeast in the lab-
Describe in words how you conducted the investigation
1 - collect leaves from outdoor plant and cut them
2 - sterilise forceps by heating in flame of Bunsen burner and allow cool before using to pick up leaf
3 - Place blue tac on inside of lid and attach the leaf
4 - Seal dish and ensure leaf is facing down on agar, leave upright for 24 hours
5 - after 24 hours, leave Petri dish in incubator upside down to prevent condensation forming on lids and leave for 24-48 hours
-The growth of leaf yeast in the lab-
What was the result of your investigation and diagram!!
Positive result should show the formation of pink colonies, indicating the growth of leaf yeast
Diagram - purple book
-The growth of leaf yeast in the lab-
What is agar?
It’s a material derived from seaweed and is used to form growth medium
-The growth of leaf yeast in the lab-
What is the purpose of nutrient agar?
It allows micro organism to grow by providing a source of food
-The growth of leaf yeast in the lab-
Why is a forceps used?
To prevent micro organisms getting onto the leaf from your hands and contaminating
-The growth of leaf yeast in the lab-
Why is the lower surface of the leaf facing down on agar?
There are more micro organisms on lower surface of leaf than on upper surface. Leaf yeasts can expel their spores down onto the surface of the agar
-The growth of leaf yeast in the lab-
Why are the Petri dishes left at room temperature?
Leaf yeasts grow well at room temperature, but higher temp will speed up growth
-The growth of leaf yeast in the lab-
Why should the dishes be incubated upside down?
Prevents condensation forming on the lids
-The growth of leaf yeast in the lab-
What is the control?
A Petri dish with no leaf
Antibiotics should not be prescribed for a person suffering from a viral infection. Suggest a reason for this
Antibiotics do not have effect of viruses
What are nutrient agar plates and it’s purpose
Dishes with additives [food]
Purpose - allow growth
-The growth of leaf yeast in the lab-
From which plant did you collect the leaf sample?
Ash
-The growth of leaf yeast in the lab-
Describe how you collected the leaf sample
Cut the leaf of an ash tree and put in a sterile container to prevent contamination and prevent leaf being crushed
-The growth of leaf yeast in the lab-
What did you do with the leaves when you returned to the lab?
Put in a container
Sterilise forceps
Attach using blue tax
What is the function of sporangium?
Produce spores
What is the function of gametangium?
Produce gametes
Function of zygospore?
Dispersal
-The growth of leaf yeast in the lab-
What aseptic measures taken to exclude unwanted micro-organisms
Wash your hands
Wash the bench with disinfectant
Keep al containers closed.
-The growth of leaf yeast in the lab-
What sterile technqiues were taken so that all micro organisms are destroyed.
Sterilise all equipment by heating a pressure cooker to 1200 C for 15 minutes.
Flame all needles or loops by placing them over Bunsen burner before and after they are used.
Open all containers for the shortest possible time and distance.
