Answer:
A sordaria ascus is useful in genetic studies because it allows scientists to see crossing over during meiosis.
Explanation:
Genetic studies became interesting with the help of Sordaria. Sordaria have a short life cycle, usually 7-12 days, and are easy to grow on nutrient agar in dish cultures. It is very much useful in studying meiotic segragation because it help the researcher in detecting the behavior of chromosomes during crossing over.
Crossing over during meiosis is the phase wherein a unique set of genetic material is produced as a result of exchange of chromosomes segments.