AP LAB 3 MEIOSIS.doc - I. Meiosis Simulation ANALYSIS AND...

I. Meiosis Simulation
ANALYSIS AND INVESTIGATION
1. List 3 major differences between the events of mitosis and meiosis
2. Compare mitosis and meiosis with respect to each of the following in table 3.2
Table 3.2
MITOSIS MEIOSIS
CHROMOSOME NO. OF
PARENTAL CELL
NUMBER OF DNA
REPLICATION
NO. OF DIVISIONS
NO. OF DAUGHTER CELLS
PRODUCED
CHROMOSOME NO. OF
DAUGHTER CELLS
PURPOSE & FUNCTION
3. How is meiosis i and meiosis ii different?
4. How do oogenesis and spermatogenesis differ?
5. Why is meiosis important for sexual reproduction?
II. Crossing Over during Melosis in Sordaria
Sordaria fimicola is an ascomycete fungus that can be used to demonstrate the results of crossing over
during meiosis. Sordaria is a haploid organism for most of its life cycle. It becomes diploid only when the
fusion of the mycelia of two different strains results in the fusion of the two different types of haploid
nuclei to form a diploid nucleus. The diploid nucleus must then undergo meiosis to resume its haploid state.
Meiosis, followed by mitosis, in Sordaria results in the formation of eight haploid ascospores contained
within a sac called an ascus (plural, asci). Many asci are contained within a fruiting body called a
perithecium. When ascospores are mature the ascus ruptures, releasing the ascospores. Each ascospore can

develop into a new haploid fungus. The life cycle of Sordaria fimicola is shown in Figure 1.