LIVING THINGS CHARACTERISTICS OF LIVING THINGS All living things…. Have CELLS—all organisms are made of 1 or more cells RESPOND to stimuli—organisms detect and respond to a change in their environment REPRODUCE—organisms make more organisms like themselves Asexual Reproduction: 1 parent Sexual Reproduction: 2 parents Have DNA—DNA is contained in cells and provides instructions for making proteins USE ENERGY—organisms use energy to carry out the chemical activities of life GROW & DEVELOP—organisms grow by increasing their # of cells OR by increasing the size of their cell NECESSITIES OF LIVING THINGS All living things need… FOOD—food provides organisms with the energy and raw materials necessary to carry on life WATER—water is necessary for maintaining metabolism. Cells are about 70% water AIR—air is a mixture of several different gases including oxygen and carbon dioxide SPACE—organisms must have somewhere to live that contains all the things they need to survive INTERACTIONS OF LIVING THINGS ECOLOGY: study of the connections/interactions among living things and their environment An environment has 2 parts: BIOTIC—living factors in the environment (trees, plants, insects, humans, etc) ABIOTIC—nonliving factors in the environment (water, soil, light, temperature, etc.) 5 Levels of Environmental Organization ORGANISM—an individual living thing POPULATION—group of individuals of the same species that live together in the same area at the same time COMMUNITY—all of the populations of different species that live and interact in an area (biotic) ECOSYSTEM—communities of organisms and their nonliving environment (biotic and abiotic) BIOSPHERE—the part of Earth where life exists The way energy moves through an ecosystem can be represented by… FOOD CHAIN: Shows how energy in food molecules (sun producers herbivores carnivores scavengers) FOOD WEB: diagram that represents the many energy pathways in a real ecosystem ENERGY PYRAMID: triangle-shaped diagram that shows the loss of energy at each level of a food chain NICHE: an organism’s way of life within an ecosystem (what it eats, where it finds shelter, how it reproduces, etc) HABITAT: the environment where an organism lives CARRYING CAPACITY: the largest population an environment can support over a long period of time LIMITING FACTOR: when 1 or more resources become scarce, occurs when a population reaches its carrying capacity