The term 'disease agent' can be summarized as a GERM, which is a four-letter word. A GERM is a microorganism that can cause disease in humans, animals, and plants. Examples of germs include bacteria, viruses, fungi, and parasites. These germs can spread through contact with an infected person or animal, contaminated food or water, or contact with contaminated surfaces. Germs can also be spread through the air when an infected person coughs or sneezes. It is important to practice good hygiene and take precautions to prevent the spread of germs.