Question

1. Compare and contrast the structure of teosinte with that of corn. Why did people believe that teosinte could not be the ancestor to corn? Why were its kernels probably not used to a great extent as food?

Answer 1

Modern corn or maize (Zea mays) is a popular staple food of the Americas. In fact, it's believed that corn reached its useful and modernised version only through systemic and advanced breeding of it's ancient parent- Teosinte, a wild Mexican grass. Today, corn has more use than any other agricutural crop. It can generate fuel, solvents, abrasives. It is used as cattle-feed, animal-bedding and adhesives. The kernel is particularly useful as starch, bran, glutamates. The stalk is used to make artificial silk or rayon, silage, paper.

Importantly, famous geneticist- Dr. Gerge W. Beadle carried out genetic studies on corn and teosinte, He found that they had very similar chromosomes. He even crossed the two species and obtained fertile hybrids that proves beyond doubt that the two species belong to the same family. His work later on led to the Nobel Prize in 1958

However, teosinte has very few physiological similarities to be considered as the progenitor of modern-day corn.

1. Teosinte has several stalks while corn has only a single stalk

2. The seeds of teosinte are triangular while, that of corn are round shaped.

3. Seeds of teosinte are encased within a hard outer covering, while that of corn are not.

4. A teosinte ear is hardly 2-3 inches in length with just 5-12 kernels, while each ear of corn is almost 12 inches long and can hold close to 500 kernels.

For the above differences, one group of scientists argue that teosinte can't be the ancestor of corn or maize.

The outer casing of the teosinte kernel is extremely hard, a mechanism to protect the seeds from predators such as birds and animals for ready consumption. The same hard casing makes teosinte inedible to humans.