Higher CO2 concentrations in the environment will decrease the number of stomata on a plant leaf. Specimens from before industrial times have greater densities of stomata than modern-day specimens, reflecting the increase in CO2 from environmental factors, such as the industrial revolution. Fossils have shown that high CO2 levels in the past (and warmer temperatures) decrease the numbers of stomata, while low levels of CO2 and ice ages have increased the numbers of stomata.
PLANT BIOTECHNOLOGY Plant biotechnology for the most part involves altering the genes of plants to create GMO (genetically modified organism) plant. These are also called biotech crops and are often used in agriculture. The goal of GM crops is to create a crop that has a trait that doesn’t occur in nature. Genes can be altered in order to increase the plants’ resistance to diseases, certain pests, spoilage, chemical herbicides, and certain environmental conditions. This affects about 12 percent of the crops in the world.
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