The hypothesis by Coleman was that the product of the ob+ gene was the appetite suppressing hormone. Hence, the homozygous ob/ob mutant are in a position to synthesize that hormone, and its circulating level would be zero. He also hypothesized that the product of the db+ gene was the receptor for the appetite-suppressing hormone. Thus, the homozygous db/db mutant would be able to synthesize the hormone but would not be in a position to respond to it. It would eat excessively and produce large amounts of body fat, which in turn would produce large amounts of appetite-suppressing hormone . In the absence of a receptor, the db/db mutant's hormone level would remain abnormally high.
Coleman's hypothesis were confirmed when the precise functions of the ob+ and db+ genes were determined. The peptide hormone encoded by the ob+ gene was named Leptin.
Answer:
Streak Test
Explanation:
A streak test is used by geologists to help determine the powdered color of a mineral. They usually use a white or black plate, scrape a sample of the mineral onto the plate, and voila!
P.S. I also had a question like this on a test before.
C, as A,B, and D aren't true.
I think A- laboratory mice are similar but not identical
