The Simple Bare Necessities of Life

Basic Needs of Living Things Almost every organism has the same basic needs: food water air a place to live

Food All living things must have food. Food provides organisms with the energy and raw materials needed to carry on life processes and to build and repair cells & body parts Organisms are grouped into 3 categories based on how they get their food (producers, consumers, decomposers).

Producers Producers produce their own food. Ex. Plants are producers. They use energy from the sun to make food from water and carbon dioxide.

Consumers Consumers must eat (consume) other organisms to get the food they need. Ex. A salamander is a consumer. It gets the energy it needs by eating insects and other organisms.

Decomposers Decomposers are organisms that get their food by breaking down the nutrients in dead organisms or animal wastes. Ex. Fungus absorbs nutrients from dead plant material in the soil.

Water Almost all living organisms are made up of approximately 70% water. The metabolism of organisms is dependent on water because most of the chemical reactions that take place in organisms involve water. You obtain your water from the fluids you drink and the food you eat. You could only survive for about 3 days without water.

Air Air is a mixture of several gases, including oxygen and carbon dioxide. Oxygen is used in respiration, the exchange of gases between living cells and their environment. Organisms that live on land get oxygen from the air. Organisms that live in water take in dissolved oxygen from the water or come up for air. Plants, algae, & bacteria get carbon dioxide & oxygen through photosynthesis, the process that converts the energy in sunlight to energy stored in food.

Place to Live All organisms must have a space to live. This space must contain all the things they need to survive. Because the amount of space on Earth is limited, organisms often compete with each other for food, water, space, and other necessities in life.

Homework: Answer the following questions: 1. How are decomposers and consumers alike? How do they differ from producers? 2. What percent of water do most living organisms consist of? 3. How might a cave, an ant, and a lake meet the needs of an organism?