Genetics: Karyotype

 Karyotypes are literally picture of chromosomes taken through a microscope, and they are used to screen for major genetic abnormalities.

In our case, we used these sample karyotypes to cut and paste homologous chromosomes and sort by size (the largest chromosomes are chromosome 1, and the smallest are chromosome 22).

A word of caution, the site provides some karyotypes showing chromosomal damage (trisomy 21, for example).  It's important to use the normal examples first, and move on to the abnormal ones if you want to do more karyotyping later (otherwise, it can be very confusing).







I had my girls do normal girl karyotypes, and the boys do normal boy karyotypes.

They enjoyed it, and it really helped them understand the homologous chromosomes and chromatids.

Genetics: Candy DNA

 Time is flying by: we are in the last section of our science survey class!



We've been doing all sorts of things with genetics, punnet squares and heredity.


One fun thing, while explaining DNA replication, was to make models of DNA out of leftover Halloween candy!

In these models, red licorice is the sense strand, and yellow is the non--sense strand. Fruit flavored tootsie rolls are the bases: cherry for adenine, blue raspberry for thymine, lime for cytosine, and grape for guanine.  We used tooth picks to link everything together, and Laffy Taffy to make the zipping and unzipping enzymes.