Tuesday, April 1, 2008
Mon-Day 1
Bio- we discussed "sex-linked" traits, which are determined by the genes that are located on the "sex chromosomes". Each human body cell has one PAIR of sex chromosomes; males have non-identical sex chromosomes, one X and one Y but females have an identical pair of X "sex" chromosomes.
We saw how the percentages of offspring that show a RECESSIVE trait CAN BE different when that trait is determined by a gene on a sex chromosome. The reason for that is that a male cannot mask/hide the phenotype from a recessive allele on its X sex chromosome because the Y chromosome has, practically speaking, no alleles to dominate over the recessive allele. Thus, sex-linked traits can be determined by the fact that NEITHER parents displays a recessive trait but ONLY the MALE offspring then display the recessive trait; this is because the recessive allele was "carried" by the mother but not phenotypically expressed (because she also had a dominant allele on the other X chromosome) and passed on to the son; the son also inherited a Y sex chromosome (from his father) that had no alleles to mask/hide the recessive allele.
Chem 7- we did some Keq expression and Keq value problems while stressing that ONLY the aq. and gaseous reactants and products go into these expressions. We noted that the BALANCED equation coefficients are used as exponents of the concentrations of their respective reactants and products.
We also learned that, "practically", there are two types of reactions that go to "completion"/about 100% products. These are:
1. reactions of two aqueous solutions that form an insoluble precipitate (which then does not appreciably dissolve to cause the reverse reaction).
2. reactions of aqueous solutions and/or liquids and/or solids that form gases (which are likely insoluble and therefore do not return to the solution for a reverse reaction).
Chem 8/9- we did some Keq expression and Keq value problems while stressing that ONLY the aq. and gaseous reactants and products go into these expressions. We noted that the BALANCED equation coefficients are used as exponents of the concentrations of their respective reactants and products. We also learned that, "practically", there are two types of reactions that go to "completion"/about 100% products. These are:
1. reactions of two aqueous solutions that form an insoluble precipitate (which then does not appreciably dissolve to cause the reverse reaction).
2. reactions of aqueous solutions and/or liquids and/or solids that form gases (which are likely insoluble and therefore do not return to the solution for a reverse reaction).
We then saw two demonstrations, one that showed a double replacement reaction going to completion and the other showing an equilibrium shift in the chromate-dichromate equilibrium mixture by increasing the concentration of a product- acid.
We saw how the percentages of offspring that show a RECESSIVE trait CAN BE different when that trait is determined by a gene on a sex chromosome. The reason for that is that a male cannot mask/hide the phenotype from a recessive allele on its X sex chromosome because the Y chromosome has, practically speaking, no alleles to dominate over the recessive allele. Thus, sex-linked traits can be determined by the fact that NEITHER parents displays a recessive trait but ONLY the MALE offspring then display the recessive trait; this is because the recessive allele was "carried" by the mother but not phenotypically expressed (because she also had a dominant allele on the other X chromosome) and passed on to the son; the son also inherited a Y sex chromosome (from his father) that had no alleles to mask/hide the recessive allele.
Chem 7- we did some Keq expression and Keq value problems while stressing that ONLY the aq. and gaseous reactants and products go into these expressions. We noted that the BALANCED equation coefficients are used as exponents of the concentrations of their respective reactants and products.
We also learned that, "practically", there are two types of reactions that go to "completion"/about 100% products. These are:
1. reactions of two aqueous solutions that form an insoluble precipitate (which then does not appreciably dissolve to cause the reverse reaction).
2. reactions of aqueous solutions and/or liquids and/or solids that form gases (which are likely insoluble and therefore do not return to the solution for a reverse reaction).
Chem 8/9- we did some Keq expression and Keq value problems while stressing that ONLY the aq. and gaseous reactants and products go into these expressions. We noted that the BALANCED equation coefficients are used as exponents of the concentrations of their respective reactants and products. We also learned that, "practically", there are two types of reactions that go to "completion"/about 100% products. These are:
1. reactions of two aqueous solutions that form an insoluble precipitate (which then does not appreciably dissolve to cause the reverse reaction).
2. reactions of aqueous solutions and/or liquids and/or solids that form gases (which are likely insoluble and therefore do not return to the solution for a reverse reaction).
We then saw two demonstrations, one that showed a double replacement reaction going to completion and the other showing an equilibrium shift in the chromate-dichromate equilibrium mixture by increasing the concentration of a product- acid.
# posted by C @ 1:24 PM 
