Final answer:
Waxy endosperm has a high amylopectin content and low amylose content, while shrunken endosperm has defective starch synthesis, leading to a shrunken appearance rather than an emphasis on amylose content.
Step-by-step explanation:
The characteristics of waxy endosperm (wx) and shrunken endosperm are related to the content of amylose and amylopectin in the starch they contain. Waxy endosperm has a high amylopectin content and low amylose content, which correlates to option 3 that states waxy endosperm has a high amylopectin content and shrunken endosperm has a low amylopectin content. Amylopectin is a highly branched form of starch, whereas amylose is a linear, unbranched polymer. Conversely, shrunken endosperm mutants are characterized by a defective starch synthesis process that leads to an accumulation of water-soluble polysaccharides instead of normal starch, resulting in the shrunken appearance of the endosperm. These facts suggest that waxy corn varieties, which have starch composed almost entirely of amylopectin, would be the opposite in amylose content compared to the shrunken endosperm.