Wednesday, April 21, 2010
Tues-Day 2
Bio - we learned some of the older techniques of biotechnology and genetic engineering. Selective breeding/artificial selection is the process by which humans breed/mate only those plants or animals that have the most desirable traits. Through "inbreeding" of just the most desirable members of the species, the succeeding generations of offspring, by percent, become more and more "true bred" or homozygous for these traits; occasionally harmful traits also are expressed as homozygous recessives, due to the increased likelihood of the homozygous condition from inbreeding.
We also discussed "hybridization"- selecting/mating similar species that have different desirable traits to produce offspring that have all of the desirable traits- that generally occurs in a certain percentage of the hybrid offspring. Unfortunately, some hybrids might get the least desirable traits from each parent.
AP Chem - we finished the Ksp equilibria unit by quantitatively solving separation of ion problems via selective precipitation; we did so for both anions and for cations.
We finished up by showing which salts could become more soluble in increasingly acidic solutions: ALL salts EXCEPT for chlorides, bromides, iodides, nitrates, and perchlorates become more soluble at lower pH's due to the hydronium ion in solution reacting with the Bronsted base anion of the salt, causing an equilibrium shift in the dissolving direction.
# posted by C @ 9:37 PM 
