Fungi

Question 1

What is like a fungus but different

Answer 1

Significant differences between fungi and oomycetes

Question 2

Fungi – Sexual and asexual reproduction

Answer 2

The asexual cycle produces mitospores, and the sexual cycle produces meiospores.
mycelium is roots of fungus these are haploid and multicellular they were produces by unicellular reproductive cells called spores.
Asexual
mycelium can use mitosis already haploid so produces unicellular spores these are genetically identical to mycelium these stay on ground and produce more mycelium
Sexual
mycelium keeps dividing getting longer underground then eventually one mycelium will release pheromones until two different mycelium will touch and these two mycelium are genetically different both are haploid and these will undergo a process called plasmogamy. This now forms heterokaryotic stage with two nuclei in one cell that are different, eventually these will fuse in a process called karyogamy (chromosomes fuse) and form one cell with one nucleus called a zygote. (no gametes).
zygote will grow into a fruiting body (mushroom body) diploid structure. A part on the fruiting body will undergo meiosis producing spores which are unicellular and haploid. These spores fall to the grown to produce more mycelium and then these can undergo either type of reproduction.

Question 2

What do ascomycetes spores contain ?

Answer 2

Ascus

Question 3

Explain the structure and types of mycelium.
How do hyphae colonise?
How do fungi eat?

Answer 3

• Fungi produce a mycelium of fine thread-like hyphae, which
  grow from the tip, this allows them to explore their environment efficiently (hyphal tip).
  Hyphae that have walls (septa) between the cells are called septate hyphae.
  Hyphae colonize by polar growth and branching.
  They secrete invertase to break down into sugars and then absorb them. Fungal secretion is (mainly) from
  the hyphal tip Enzymes, proteins, effectors, metabolites are secreted and these may be to eat, manipulate or hide from the host

Question 4

What are slime moulds

Answer 4

Slime moulds are single cells with many nuclei.

Question 5

Fungi are heterotrophic. Different types of lifestyle include;
Necrotrophic
Saprotrophic
Biotrophic pathogens
Hemibiotrophic pathogens
mutualistic relationships

Answer 5

Necrotrophic =aggressive pathogens
Saprotrophic= decompose dead material
Biotrophic pathogens = live whole life cycle in live host
Hemibiotrophic pathogens= Has a phase of symbiotic
growth with the host before necrotrophy
Mutualistic Lichens and mycorrhyzal fungi= exemplify
mutualistic relationships where there is a benefit to each partner

Question 6

What is an example of a toxin released by fungi?

Answer 6

Mycotoxins which are toxins that harm humans and animals

Question 7

Ergot – an arsenal of chemical weapons

Answer 7

Produces many alkaloids in sclerotia with circulatory and neurological functions

Question 8

Rice blast fungus (Magnaporthe oryzae) lives inside plant leaves

Answer 8

Plant pathogens are responsible for 15 – 30 % loss of food crops.
* Rice blast fungus (Magnaporthe oryzae) is the major pathogen of cultivated rice globally
and kills enough rice each year to feed 60M people.
Magnaporthe oryzae life cycle involves a symbiotic relationship