It is called a sister chromatid, not a polar body.
The answer is Walter Hess
Hess manipulated the diancephalon of the brain of cats by inserting metal rods in the hypothalamus regions of the brain, where the diencephalon is located, and passing electrical current through the rods to the brain region. He noticed that the cats, among other complex behavioral changes, would curl up and sleep.
A pedigree is a symbolic diagram that is used to show the presence and presentation of specific alleles in the families of both parents. This is used mostly for genetically controlled diseases and conditions. If a couple is in genetic counseling a pedigree is valuable in helping to determine the risk of that couple having a child that will either present with the condition or be a carrier for the condition. A pedigree is also composed in a way, with shapes and colors, that is an easy to understand visual representation of the inheritance patterns.
