Friday, April 4, 2008
Fri-Day 1
Bio- HW: text 12.1 outline is due on TUESDAY.
we discussed polygenic inheritance: a trait that is controlled/determine by more than one gene; these genes can even be on different (nonhomologous) chromosomes. The resulting trait typically has a wider/more varied range of phenotypes as is the case with eye color. So, instead of just having a dominant brown allele and a recessive blue allele, there can be more combinations among several different genes, which causes the various possible eye color shades.
We also discussed several examples of ENVIRONMENTAL effect (nurture) on GENE EXPRESSION (an organism's nature): people with the genes for melanin production do not have very dark skin unless they are exposed to sunlight, which turns the gene ON so that transcription and translation of that gene occur.
Chem 7-9: we prepped for the quarterly; over the weekend, work on the Regents exam to see what you need to work on.
we discussed polygenic inheritance: a trait that is controlled/determine by more than one gene; these genes can even be on different (nonhomologous) chromosomes. The resulting trait typically has a wider/more varied range of phenotypes as is the case with eye color. So, instead of just having a dominant brown allele and a recessive blue allele, there can be more combinations among several different genes, which causes the various possible eye color shades.
We also discussed several examples of ENVIRONMENTAL effect (nurture) on GENE EXPRESSION (an organism's nature): people with the genes for melanin production do not have very dark skin unless they are exposed to sunlight, which turns the gene ON so that transcription and translation of that gene occur.
Chem 7-9: we prepped for the quarterly; over the weekend, work on the Regents exam to see what you need to work on.
# posted by C @ 5:44 PM 
