Some people have hitchhiker's thumbs, which bend backwards with a large angle between the two segments (phalanges). The myth is that there are just two kinds of thumbs, straight thumbs (S) and hitchhiker's thumbs (H), and the trait is controlled by a single gene with two alleles, with the allele for S being dominant.This was proposed by Glass and Kistler (1953) and has been the subject of very little research since then.he myth is that there are just two kinds of thumbs, straight thumbs (S) and hitchhiker's thumbs (H), and the trait is controlled by a single gene with two alleles, with the allele for S being dominant. This was proposed by Glass and Kistler (1953) and has been the subject of very little research since then.
Two fundamental cellular processes are cellular respiration and photosyn-thesis. Cellular respiration is the process by which cells release stored energy from sugars. Photosynthesis is the process in which producer cells use carbon dioxide, water, and nutrients to produce glucose and oxygen.
Photosynthesis uses water, sunlight, and carbon dioxide from the atmosphere to create glucose molecules, and releases oxygen as a by-product. Cellular respiration uses glucose molecules and oxygen to produce ATP molecules and carbon dioxide as the by-product. Photosynthesis takes place only when there is sunlight. Cellular respiration occurs at all times. Photosynthesis involves conversion of one type of energy into another: light energy into chemical energy. Cellular respiration involves using that chemical energy and breaking it down to release energy.