Answer to Question 1
The three main trophic categories are the producers, the consumers, and the decomposers. Producers capture energy from the Sun or from chemical reactions to convert carbon dioxide to organic matter. Most producers are green plants. Consumers feed on organic matter as their source of energy. Examples of consumers include all animals, fungi, and most bacteria. Decomposers have the ability to digest and feed off of detritus, which includes leaves, grasses, and fecal wastes and dead bodies from higher trophic levels. Examples of decomposers include scavengers, like vultures, and other detritus feeders like earthworms, some species of fungi, and also some bacteria and other microbes.
Answer to Question 2
Two major reasons to replace fossil fuels are their limited availability and impact on the environment. When burned, fossil fuels contribute to increasing levels of carbon dioxide in the environment. The current administration has made strides in decreasing our dependence on fossil fuels, but the need to get over political and infrastructure issues here in the United States limits our ability to move forward with renewable energy sources.
2-1b Structure of the water molecule
Children may sometimes sort their toys into different categories.
Vienna: Social Structure and Social Interaction
Structure of the g complex bound to DNA
Main arteries of the arm
Typical leaf structure of eudicots (left) and monocots (right).