What you will learn in Ratios, and what they are a statement about

1. 1. Mendel's problem, and why peas

   The four decisions that made the experiment readable, and what happens when any of them is made differently.

2. 2. One gene, run for real

   Offspring sampled one at a time, a running proportion that wanders and settles, and a test that refuses to run on four plants.

3. 3. Where the laws come from

   The metaphase plate and the dihybrid square on one screen, with the ratio falling out of the gamete proportions.

4. 4. When Mendel's rules bend

   Five patterns that depart from three to one, a trait built from many loci, and two sliders that separate facts a learner usually has fused.

5. 5. Sex, and what rides along with it

   One reciprocal pair on an X-linked gene, the same pair on an autosome, and the arithmetic that follows from having one X.

6. 6. Reading a family, and mapping a chromosome

   Four pedigrees that leave four, three, two and one mode standing, and a map built from 1448 flies.