For example, mutagenized yeast strains cannot be used for further genetic analysis such as tetrad analysis.
2.
Data based on tetrad analysis from several species of fungi show that only a minority ( on average about 34 % ) of recombination events during meiosis are COs ( see Whitehouse, Tables 19 and 38 for summaries of data from " D . melanogaster " during meiosis in females there is at least a 3 : 1 ratio of NCOs to COs.