Cold sores - painful sores on the lips and around the mouth, caused by a virus. Canker sores - painful sores in the mouth, caused by bacteria or viruses. Thrush - a yeast infection that causes white patches in your mouth. Leukoplakia - white patches of excess cell growth on the cheeks, gums or tongue, common in smokers.
Energy and Metabolism. All living organisms need energy to grow and reproduce, maintain their structures, and respond to their environments. Metabolism is the set of life-sustaining chemical processes that enables organisms transform the chemical energy stored in molecules into energy that can be used for cellular processes.
All the living things, or organisms, and nonliving things that interact in a particular area make up an ecosystem. Organisms live in a speciï¬c place within an ecosystem. An organism obtains food, water, shelter, and other things it needs to live, grow, and reproduce from its surroundings.Some organisms make their own food in a process called photosynthesis. Other living things depend on plants and algae for food.The place where an organism lives and that provides the things the organism needs is called its habitat. An organism interacts with both living and nonliving parts of its habitat. The living parts of an ecosystem are called biotic factors.rganisms live in a speciï¬c place within an ecosystem. An organism obtains food, water, shelter, and other things it needs to live, grow, and reproduce from its surroundings. Some organisms make their own food in a process called photosynthesis. Other living things depend on plants and algae for food.