PS263 Chapter Notes - Chapter 4: Cytosine, Zygosity, Chromosome
Document Summary
Genes come in pairs because they are aligned along chromosomes that also come in pairs. Several genes overlap on a stretch of chromosome. Part of a chromosome alters the expression of a gene without coding for any protein of its own. Strand of dna serves as a template for the synthesis of rna ribonucleic molecules. Messenger rna molecule serves as template for the synthesis of protein molecules. Order of dna bases determines order of corresponding bases along rna molecule which in turn determines order of amino acids that compose a protein. Identical pair of genes on two chromosomes = homozygous for that gene. Unmatched pair of genes = heterozygous for that gene. Ex gene for blue eyes on one chromosome and gene for brown eyes on other. Shows strong effect in either homozygous or heterozygous condition. At least 10 genes contribute to eye colour. Possible to express a gene in some cells and not others.
