Genetics

[|Isn't Science Grand (YouTube Video])
 * A cute video on Mendelian genetics and F1 and F2 crosses.

From Rob0bops@aol.com I am not sure this will help but I will tell you what we do. We use ...ah...poker chips... to represent the alleles. Yes, not an improvement over the beads so keep the beads there. But what helps them understand the beads is that first we discuss blending inheritance. I introduce the subjects with this very silly video til 2min30sec: http://www.youtube.com/watch? v=eYkT9JY8FQw.

We pour purple and white paint together to show that blending doesn't explain why we only have purple or white not in between colors of peas plants. Then we discuss the fact that Mendel suggested we have something in us that is not purple or white but that tells the cell to make the purple or white color. They instantly recognize that as genes and realize that there may be two copies of them as they have seen a human karyotype by then and realize that humans have two copies of most genes [ do sort of ignore for a time polyploidy]. The we try to figure out a way the combinations of poker chips could give use purple and white flowers only as in the generations tested by Mendel.

Then we test this by crossing two heterozygous purple plants by putting one each of the poker chips in a brown bag, have each partner pull out one and then record with a hash mark what color plant then have. Amazingly, with a little time and a lot of groups (we works in twos in this) we often get very close to three to one. [Encourage them to work fast].

I know its very simple but maybe seeing the paint demonstration or hearing about the other theories at the time first helps as they really do seem to get it...

Robin Wooten Lenexa, Kansas

[|The Case of Desiree's Baby. A Case Study In Skin Color]

[|Genetic Traits Activities]