1. Emphasize how the study of biology and genetics has become the study of (a) the biochemistry of genetic processes, (b) DNA replication, (c) the transfer of information to a usable form in building proteins, and (d) the use of the proteins (often as enzymes) to produce the phenotype of the individual.
2. Consider how much the link between the DNA nucleotide sequence and the amino acid sequence of proteins has led to the current knowledge of what happens in a cell and how to "fix it" through genetic engineering. (Prepare for the coverage of the material in the next few chapters.)
3. Follow the progression of scientific understanding
of this material from the one geneñone enzyme hypothesis
to the one geneñone polypeptide hypothesis, and take the
next step to the one geneñone gene product hypothesis that
would include tRNA and rRNA as gene products. These still do not
fit the one geneñone polypeptide hypothesis, since they
do not involve polypeptides and yet are usable structures defined
by DNA gene sequences.