Final answer:
The purpose of inserting a normal gene into mutant yeast is to correct a genetic defect, which helps study gene function and evolutionary processes. Yeast is also utilized to produce biological substances and for reverse genetics to determine gene function.
Step-by-step explanation:
Inserting the normal gene into mutant yeast serves a purpose similar to gene therapy in humans. It allows researchers to correct a genetic defect by introducing a functional copy of the gene, which can then be expressed to restore normal function in the cells. In the case of yeast, this is useful for both scientific research and practical applications. For example, by specifically addressing mutations like ade-2 (which results in a red colony color) and ade-7 (which turns the colony white), scientists can study gene function, mutational effects, and the evolutionary implications of genetic variation. Moreover, the use of Yeast Artificial Chromosomes (YACs) enables the handling of large DNA sequences, further supporting the study of genetic phenomena.
In some contexts, the purpose of inserting genes into yeast is to produce substances of interest. For instance, the gene for hepatitis B virus surface antigen can be inserted into yeast to grow the virus protein. This highlights the versatility of yeast as an organism for producing biological products and studying genetic functions. Additionally, by utilizing reverse genetics, the function of specific genes can be analyzed through observing changes in phenotype when these genes are purposely mutated or removed.
The use of genetically engineered yeast therefore has broad implications for understanding genetics, conducting research, and applying biotechnological processes that can eventually lead to improvements in medical and industrial practices.