Fungi 2 Flashcards
What type of organism are fungi?
Fungi are eukaryotes.
What is the nutritional mode of fungi?
Fungi are heterotrophs, meaning they require organic foodstuffs.
What type of fungi are saprophytic?
Moulds are often saprophytic, meaning they feed on dead or decaying organic matter.
What are the two main forms of fungi?
Fungi can be unicellular (yeast) or multicellular (moulds or higher fungi)
What is the oxygen requirement for most fungi?
Most fungi are aerobes, requiring oxygen for survival.
How do some yeast differ in their oxygen requirements?
Some yeast are facultative anaerobes, meaning they can survive with or without oxygen.
What is the structure of hyphae in moulds?
Moulds possess hyphae, which are long, thread-like structures. A mass of hyphae is called a mycelium. They have an outer cell wall and a hollow lumen that contains cytoplasm and organelles.
What is the difference between septate and aseptate hyphae?
Septate hyphae have cross walls (septum) with pores for movement of cytoplasm and nutrients.
Aseptate hyphae lack cross walls and are continuous.
What is the role of vegetative hyphae?
Vegetative hyphae form mycelia and anchor the fungus in its substrate to help obtain nutrients from the environment.
What are reproductive hyphae and what are they often called?
Reproductive hyphae are less common and are often referred to as aerial hyphae because they stick up in the air and form reproductive spores.
How do fungi digest decaying plant material?
Fungi use exodigestion, secreting cellulolytic enzymes to break down cellulose and access cellular components.
What is the preferred pH of fungi?
Fungi are acidophiles, meaning they prefer acidic environments.
What temperature do fungi prefer?
Fungi are mesophiles, meaning they thrive in room and body temperature.
What is the role of mycorrhizae in fungi?
Mycorrhizae are mutualistic partnerships between plant roots and fungi, where fungi enhance plant access to water and minerals, while plants provide carbohydrates to the fungi.
What is the oxygen requirements of mould?
Moulds are obligate aerobes, meaning they rely on aerobic respiration for energy.
What is the oxygen requirements of yeast?
Yeast may be obligate aerobes or facultative anaerobes and can use glucose in respiration.
What condition can Malassezia cause?
Malassezia can cause dandruff by feeding on fatty secretions from the skin.
What is Pneumocystis and how does it affect humans?
Pneumocystis is a fungal pneumonia that is commensal in healthy individuals but can become opportunistic in immunocompromised people, causing lung infection.
What is Stachbotrys chartarum and what symptoms can it cause?
Stachbotrys chartarum, also known as black toxic mould, produces mycotoxins that can cause respiratory issues, organ damage and mental impairment.
How do yeast reproduce asexually?
By budding, where a bud forms on a parent cell, receives a copy of the nucleus, and then separates to form a chain of daughter cells.
How do yeast reproduce sexually?
Yeast can reproduce sexually through spore formation.
What is the difference between the asexual spores of Penicillium and typical moulds?
In Penicillium, chains of spores (conidia) form at the end of aerial hyphae and are not enclosed in a sac, unlike typical moulds which form spores inside a sporangium.
How do moulds reproduce asexually?
Moulds reproduce asexually by forming spores inside a sporangium, where the cytoplasm divides to form sporangiospores.
How do fungi reproduce sexually?
Fungi reproduce sexually through formation of sexual spores.
