Fungi Flashcards
How is Fungi classified?
-Fungi use to be considered lower plants due to lack of movement
- kingdom fungi includes: mushrooms, toadstools, moulds, mildews, yeasts, rusts and lichens
- two largest phyla that classify fungi=
Basidiomycota and ascomycota
What are the differences and similarities between plants, fungi and animals
Although they have attributes of both plants and animals they do not fall under either.
What is a mushroom ?
-The term mushroom applies to a fleshy fruit body with a wide cap and gills underneath and having a more or less cylindrical stipe(stalk)
- this is simply a visual manifestation of a particular stage in the life cycle of an organism that generally lives below the surface of its habitat for most of the year.
- hidden below the soil, inside wood or dung or leaves or sometimes on the surface, is the main body-Mycelium
It is a extensive network of fine, hair like filaments called Hyphae, which are the basic building blocks of a fungus.
- these threads extend at their tips to form branches that develop and spread through the substrate
What is Mycelium responsibility?
- It is responsible for nutrition and development of the fruit bodies of the mushroom.
How long can mycelium survive ?
Mycelium can be perennial and can survive for centuries.
Some as old as 2000 years
Explain nutrition of fungi
- Fungi do not photosynthesise
- they are heterotrophs meaning they feed of others
- fungi use specialised enzymes called exoenzymes that are secreted from the tips of the growing hyphae onto their surroundings to break it down and digest it outside of the body.
- large food molecules are broken down into smaller once brought into the Hyphae
- cellular respiration takes place inside fungal cells(carbs and fatty acids broken down into ATP(energy))
Briefly Explain reproduction in Fungi
Various types of fungi able to reproduce asexually or sexually by producing spores that can be released into a suitable environment or carried away to new environments via air and water and can give rise to a new fungal body
Explain how asexual reproduction in Fungi takes place
-Occurs through mitosis
- fungal cell divides and produces identical copies of it self
- in single celled fungi like yeast this is known as budding, small offshoot or bud emerges from parent cell slowly growing in size , nucleus divides into two until it is the same size as the parent cell then it splits off
Multicellular fungi such as moulds produce asexual spores
Explain how sexual reproduction in Fungi takes place
-Spores produced through meiosis
- spores containing half the number of parental chromosomes
- once released spores germinate into tree like mycelia and are ready to “mate”
- primary mycelium divided into segments containing a single nucleus
- mating takes place when two primary mycelia come in contact with one another and form secondary mycelium.
- each segment of secondary mycelia has two nuclei, one from each original segment.
- after several steps these two nuclei join to make one nucleus with the same number of chromosomes as the parent cell
- the cycle then repeats itself
Name the different types of fungi and their role in nature
Saprophytic fungi - feed off of dead or decaying plant and animal matter.
- decomposers of organic material that can not be decomposed other wise( chitin of insects and animals and cellulose and lignin in plants)
- natures own recyclers, turning dead leaves, branches, logs and roots into to hummus, minerals and nutrients, which are then eventually returned to the soil to be utilised by plants for growth and new generations of organisms
Mycorrhizal fungi(symbiotic)
- form mutualistic relationships with higher plants
- fungi Hyphae penetrate roots of host obtaining carbs, making use of this food source to develop an extensive mycelial network in the substrate, in return the fungi decomposes organic material in the soil making minerals available to the plant for plant growth also helping with water absorption
parasitic fungi
- parasitise living plants, insects and animals
- in plants causing leaf spot or trunk rot, killing of certain plants in a area allowing for growth of another
- in insects and animals, athletes foot or ringworms, helping with natural biological method of population control
What is ment by fungal association?
Many species of fungi have evolved to develop highly specialised relationships with extremely specific host species
Name 3 examples of fungal associations
Lichens
Termite fungus gardens
Tree communication using fungi
What are lichens made of and explain the relationship
-Are merged organisms formed by fungi in association with a partner that is able to photosynthesise such as green algae or bacteria.
- algae provide fungi with carbs which are produced via photosynthesis and in turn the fungi protects the algae from drying out via retaining and absorbing water and also provides minerals
What are the roles of lichens
- They play an important role in the environment by colonising ecosystems and microhabitats.
- first organisms to inhabit bare rocky areas and play a role in soil formation
- used to serve as a measure of air pollution levels due to the fact that they are extremely sensitive to toxic compounds and have no way of excreting elements they absorb
