Minnie wants to investigate the way changes in the hours of daylight affect the loss of leaves in maple trees. What is Minnie most likely to include in her investigation?
Answers
Explanation:
Autumn color signals the onset of senescence that leads to dormancy, a process that allows trees and hardy perennial plants to survive the cold temperatures and meager daylight of winter in extra-tropical climates. Cellular bodies, called chloroplasts, toil inside leaves all summer long, capturing sunlight in green pigment called chlorophyll to combine with water and carbon dioxide to make sugars -- carbohydrates that power the tree’s respiratory system. In autumn, chlorophyll production dwindles as the number of daylight hours falls below 12, causing leaf colors to change about the same time across latitudes regardless of other factors. The departure of chlorophyll reveals yellow, orange or brown pigments, called cartenoids, in the cells. Other red, purple or blue pigments, called anthocyanins, rush in to fill the void, consuming excess carbohydrates and providing leaves with a brightness known as peak color.
Weather
Weather can help trigger dominance by cartenoids and anthocyanins. Maples (Acer spp.), especially sugar maples (A. saccharum) and soft maples (A. rubrum and A. saccharinum), are especially sensitive to heavier than normal rain. This causes the trees to shut down carb production. Heat compounds the effects of drought because it increases tree perspiration, called transpiration, further taxing the tree’s system. In Wisconsin’s drought year of 2012, where spring began with 80 degree days in March and stretched into a hot, dry summer, trees began to turn as much as two weeks early. Spectacular colors followed drought-breaking rains and cooler weather.
Answer: b
Explanation: