Short answers, pulled from the story.
A bean is the seed of plants in many genera of the legume family, Fabaceae, used as a vegetable for human food or animal feed. The seeds are sold fresh or dried as a pulse. As legumes, the plants fix nitrogen and form seeds with a high protein content.
Beans were cultivated in an early form in Thailand from the early seventh millennium BCE, predating ceramics. Large-seeded broad beans did not appear in the Aegean, Iberia, and transalpine Europe until the second millennium BCE. The oldest-known domesticated beans in the Americas, found in Guitarrero Cave in Peru, date to around the second millennium BCE.
Raw beans, especially red kidney beans, contain a flavourless toxin called phytohaemagglutinin, a lectin that must be destroyed by cooking. Even 4 or 5 raw beans may cause severe stomachache, vomiting, and diarrhea. Boiling the beans for at least ten minutes is recommended, and under-cooked beans may be more toxic than raw ones.
India is the largest producer of pulses, accounting for 17.56 million metric tons in 2016, or 21.47% of the world total of 81.80 million tons. India also leads dry bean production of the genus Phaseolus, followed by Myanmar and Brazil. Tanzania is the most important producer in Africa.
Beans contain large sugar molecules called oligosaccharides, particularly raffinose and stachyose, that the human digestive tract cannot break down. Bacteria in the large intestine digest them instead, producing gases such as methane that are released as flatulence. The enzyme alpha-galactosidase, extracted from the fungus Aspergillus niger, has evidence of reducing it.
The Three Sisters is a companion planting method used by Pre-Columbian peoples as far north as the Atlantic seaboard, in which beans were interplanted with maize and squash. The tall corn stalks acted as support for the climbing beans.
A Mexican jumping bean is a segment of a seed pod occupied by the larva of the moth Cydia saltitans, and sold as a novelty. The pods start to jump when warmed in the palm of the hand. Scientists suggest the resulting random walk may help the larva find shade and survive hot days.