Midterm 1 Flashcards
What are yeast?
A fungi
What is the processes for the life cycle of the ‘a’ haploid strain of S. cerevisiae?
Budding, Mitosis, conjugation, sporulation + meiosis, germination, and back to budding
When does the shmoo structure occur during reproduction?
After the first round of mitosis when the two strains are first meeting.
What does the structure change into during the conjugation stage?
A zygote
When does the yeast become a diploid cell?
After conjugation
What is the cell called during the sporulation and meiosis stage?
ascus
What is produced after germination?
Four haploid (1N) segragants of meiosis
What is sporulation?
The process of meiosis that diploid yeast cells undergo when there is a deprivation of carbon and nitrogen. (food starvation)
What are the two types of respiration used by bakers yeast?
aerobic sugar: CO2
anaerobic sugar: Ethanol
Describe bakers yeast
unicellular eukaryote with linear DNA and 16 chromosomes in haploid
What is vegetative reproduction
Haploid -> haploid
Diploid -> diploid
and budding
3 types of sexual reproduction
Mating (conjugation)
between a and alpha and makes shmoos and leads to cell fusion and zygote formation
During Starvation
Change from mitotic to meiosis and sporulation occurs. Diploid ->haploid (stress resistant ascospores)
Nutrient rich environment
ascospores begin to germinate and form stable haploid cells
epistasis
the interaction of separate non-allelic genes, such that one gene interferes with the expression of another.
genetic complement
when an organism with a mutation that produces the mutant phenotype produces offspring with the wild-type phenotype when mated or crossed with an organism with a functional copy of that gene. In this case, the other strain’s genome supplies the wild-type allele to “complement” the mutated allele of the strain’s genome
auxotroph
a mutant strain that requires the addition of a nutrient to the media for growth.
