-Mechanical (gravity or position):
Ex.: A car on a ramp.
Ex.: A battery, a handwarmer, a lightstick, a flashlight (have batteries that use chemicals), a grill, a car engine, a firefly, an athlete (they use chemicals to move), and a firecracker.
Ex.: A pulled-back slingshot.
Ex.: The sun
Ex.: A lightbulb
Ex.:P A Photoclavic Solar Cell, a battery, and a windmill.
Ex.: the sun, a grill, a lightstick, a firefly, a firecracker, a flashlight, and a Photoclavic Solar Cell (changes radiant energy to electrical energy.
-Mechanical (wind or motion):
Ex.: a bike, a radiometer, an athlete, a car engine, and a toy car.
Ex.: a firefly, the sun, a grill, a car engine, a firecracker, a flashlight, and a handwarmer
Ex.: a toy car and a firecracker
During the respiration process, animals inhale all of the gases in the atmosphere, but the only gas that is retained and not immediately exhaled is oxygen. Plants, however, take in and use carbon dioxide gas for photosynthesis. Carbon dioxide enters through tiny holes in a plant's leaves, flowers, branches, stems, and roots. Plants also require water to make their food. Depending on the environment, a plant's access to water will vary. For example, desert plants, like a cactus, have less available water than a lilypad in a pond, but every photosynthetic organism has some sort of adaptation, or special structure, designed to collect water. For most plants, roots are responsible for absorbing water.
The last requirement for photosynthesis is an important one because it provides the energy to make sugar. How does a plant take carbon dioxide and water molecules and make a food molecule? The Sun! The energy from light causes a chemical reaction that breaks down the molecules of carbon dioxide and water and reorganizes them to make the sugar (glucose) and oxygen gas. After the sugar is produced, it is then broken down by the mitochondria into energy that can be used for growth and repair. The oxygen that is produced is released from the same tiny holes through which the carbon dioxide entered. Even the oxygen that is released serves another purpose. Other organisms, such as animals, use oxygen to aid in their survival.