Chapter 7 Summary

The topics covered in this chapter can be summarized as follows:

• The Central Dogma describes the information flow from nucleic acids to proteins.
• Garrod’s observations showed that there is a connection between genes and enzymes.
• Beadle and Tatum proposed that one gene encoded one enzyme.
• It was an example of how to screen for genetic mutants, and therefore characterize biochemical pathways or biological processes.
• Forward genetic screening aims to find the molecular basis for a certain phenotype whereas reverse genetic screening aims to find the phenotypic effects that a gene might have on the organism.
• Somatic mutations occur in non-reproductive cells which affect the current individual, while germline mutations occur in the gametes which affect future generations and not the individual.
• Mutation can alter a gene into different levels and types of expression.
• Not all base pair changes (mutations) cause detectable changes in an organism. The efficiency of mutant screening is limited by silent mutations, redundancy, and embryonic lethality.
• Cystic Fibrosis is a genetic disease caused by the mutation in the CTFR gene.