Biology: Fungi

Made for bio exam summer 2026 (add in full terms for LC)

Nature of fungi

Eukaryotic

What does eukaryotic mean

has a membrane bound nucleus and organelles

What method of nutrition do fungi use

heterotrophic nutrition

Two types of heterotrophic nutrition

• parasitic

• saprophytic

Saprophytic definition

obtain nutrients from dead organic matter (decomposer)

Examples of saprophytic fungi

mushrooms and moulds

Parasitic definition

feed on another organism (live host) causing harm

Two types of parasitic fungi

obligate and faculative

Obligate parasite definition

can’t live without host

Faculative parasite definition

can live with or without a host

Example of a disease caused by parasitic fungi

ahtlete’s foot

Example of a poisonous mushroom

death cap

Example of an edible mushroom

field mushrooms

How to differentiate between poisonous and edible mushrooms

use a key

Parts of the rhizopus

• stolon

• hypha

• rhizoids

• mycellium

• sporangiophore

• apophysis

• columella

• sporangium

• spores

What are the long thin threads that fungi are made of called

hyphae

What is it called when hyphae combine in masses

mycelium

Three types of hyphae

• stolons

• rhizoids

• sporangiophores

Stolon definition

hyphae that grow across the surface of the substrate, allows fungus to spread

Rhizoid definition

hyphae that grow down into the substrate, provide anchorage and absorb digested food

Sporangiophore definition

hyphae that grow vertically up above the substrate and prodce sporangium for reproduction

When do fungi reproduce NOT asexually

when under harsh or adverse environmental conditions

Method in asexual reproduction phase (sporulation)

• hyphae grow vertically and make sporangim

• Mitosis in sporangium makes mass of haploid cells

• Cells develop resistant walls to become spores

• Dry conditions: sporangium dries and bursts to release spores

• If they land on suitable substrate, germination and new mycellium form

What does fungi sexual reproduction form

zygospores

Two strains of mycellia

positive and negative

Method of fungi sexual reproduction

• positive and negative strains grow close together

• hyphae swell and contact

• nuclei (progametangia) move into each swelling

• cross walls produce gametangia, held by suspensors

• wall between gametangia breaks down

• nuclei fuse to fertilise, many diploid nuclei form

• zygospore forms around old gametangia

• parent hyphae die and zygospores released

• when suitable conditions, zygospores germinate through meiosis

• produces haploid hypha, grow to sporangium

• nuclei in sporangium form spores (mitosis), release new hyphae and mycelia

Structure of yeast cell

• unicellular

• oval/spherical

• haploid nucleus

• central vacuole

• chitin cell wall

Main method of yeast reproduction

asexual (budding)

Process of budding

• small extension forms

• bud enlarges and fills with cytoplasm

• parent cell nucleus divides (mitosis)

• second nucleus moves into bud

• bud grows and may separate or form colony

What nutrition method does amoeba use

heterotrophic

Amoeba structure

• small amount of cytoplasm surrounded by membrane

• no fixed shape

• cytoplasm can push out to form pseudopodia

Organelles inside the amoeba

• nucleus

• food vacuole

• contractile vacuole

• cell membrane

Function of the nucleus

controls activities of the cell

Food vacuole definition

digests ingested food particles

Pseudopia function

engulfing prey and movement

Contractile vacuole funtion

osmoregulation

Cell membrane function

allows diffusion of gases/water

Precautions when working with microbes

• swab benches and wash hand with anti-microbial soap before and after

• use only sterile equipment and growth media

• treat all cultures as potentially dangerous

• when inoculating on agar plate, only open lid slightly to prevent contamination

• dispose of all materials safely (autoclaving)