Fungi Flashcards
Fungi
-mycology is the study of fungi
-eukaryotic cells and heterotrophic
-don’t have chloroplast
-cell walls are made out of chitin - tough carbohydrates
Parasitic fungi
Live in or on a live host causing harm
-obligate parasites- take food from live host
Facultative parasites- get foot from live or dead host
Saprophytic fungi
Act as decomposers - feed on dead organisms
Vital for the environment as they recycle nutrients
Eg mushrooms
Adv of fungi
Yeasts are used to produce alcohol
Food sources eg mushroom
Disadv fungi
Destroy food and crops - blight
Fungal diseases of plants and humans and animals
Rhizopus
-saprophytic fungi
Bread mould fungus
Rhizoids
Anchor the fungus and used for absorption
Hyphae
Digest and absorb the substrate on which they grow
Mycelium
A mass of hyphae
Stolons
Enables fungus to spread rapidly
Sporangiophore
Stem of fungus
Sporangium
Produces haploid spores
Columella
Feed spores
Spores
Used in asexual reproduction
Asexual reproduction - rhizopus
Sporulation - process of making haploid spores
Sporulation process
•after a few days growth,hyphae grow upwards - sporiangiophores
•the tip swell & produce a sporiangium contents divide by mitosis
•each cell develops resistant wall =spore
•each spore has one haploid nucleas
•base of sporangium is a wall called columella
•in dry conditions the sporangium fires out and opens to realise many spores
•each spore blows away and grows into a new hypha if it lands on a suitable substrate
Sexual reproduction
Drought unsuitable temp conditions
Sexual reproduction process
•hyphae from OPP strains grow close together
•swellings form opp each other and grow towards and touch
•nuclei move into each swelling forming progametangia
•cross walls form to produce gametangia
•many fertilisations produced a number of diploid zygote nuclei
•black zygospore forms around nuclei
•when suitable conditions zygospore germinated by Mieosis
Function of zygospore
Enables rhizopus to survive drought and aids in dispersal
Yeast
Unicellular
Round
Have thin cell walls made of carb chitin
Yeast asexual reproduction
Budding
•parent cell divides by mitosis
•the bud enlarges and fills with cytoplasm
•this bud may separate or remain attatched
Adv asexual reproduction
Rapid
No variation
Disadvantages of asexual reproduction
Increased risk of disease
No variation
