Living organisms are entities that exhibit the characteristics of life, including growth, reproduction, response to stimuli, and metabolism. They can be classified into various categories, such as plants, animals, fungi, and microorganisms. Each group has unique features that help them adapt to their environments and fulfill their roles in ecosystems. All living organisms are made up of cells, which are the basic units of life. These cells carry out essential functions, such as converting food into energy and repairing tissues. Living organisms interact with each other and their surroundings, forming complex relationships that sustain life on Earth.