Chapter 32.2- Reproduction Flashcards
What are the two things fungi must do to complete life cycle?
- find males to mate with
- they must be able to disperse from one place to another
What is the benefits of having spores?
to disperse over long distances where hyphaes cannot and find food when there is a food shortage
What is the purpose of fruiting bodies?
release sexually produced spores into the air for dispersal, and sexually produced spores are released high above the ground.
Where does asexual reproduction takes place?
production of haploid spores by mitosis
Where does sexual reproduction takes place?
takes place as two haploid cells (often male and female gametes) fuse
to form a diploid zygote through meiosis.
Steps of asexual reproduction of fungi:
Steps of sexual reproduction of fungi:
- germination and dispersal:
- Plasmogamy: the cytoplasmatic union of two cells
- Heterokaryotic cell: the period between cell fusion and nuclei fusion
- Karyogamy: the fusion of the nuclei
5.Zygotes are formed - Meiosis
- Spores
Dikaryotic
- Heterokaryotic cells with two
genetically distinct haploid nuclei n+ - new septa form duplicate nuclei replicate so each contain haploid
What is special about dikaryotic fungi?
the separation of
plasmogamy and karyogamy is neither distant in space nor long in
time
How does parasexual fungi generate genetic diversity?
- asexual means
- ## they cross over DNA during mitosis
Fungi have different mating types that are
genetically determined and prevent self-fertilization.
Fertilization can take place only
between individuals that have different alleles at the mating-type gene.
In some species, there are only two mating-type alleles
Steps if parasexuality
- haploid nuclei in a heterokaryotic cell undergo karyogamy to diploid nucleus
- Rare crossing over during mitosis and cells loses excess chromosomes down the line
- The nuclei with the restored haploid chromosome but novel gene combination
