(1) There is a genetic factor controlling amylopectin synthesis and a genetic factor controlling amylose synthesis in rice cells. When forming gametes, the two genetic factors separate into different gametes, and the gametes containing amylopectin genetic factors synthesize amylopectin, which turns orange-red when exposed to iodine; Amylose synthesized by gametes containing amylose genetic factor turns blue-black under the action of iodine, and the ratio is 1: 1.

(2) Mendel separation phenomenon.

(3)2