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Science_Lab_Yellow / Lesson 3: Living Things

Living Things Organized
What will we be learning today?

  • In this lesson, we are going to learn all about how living things are organized.

How Are Living Things Organized?

  • The Blackland Prairie, like all ecosystems, is home to many different organisms. Each kind of organism, whether an animal, plant, fungus, protist, or bacterium, is a member of a different species. All the organisms of a species living in the same area make up a population.

    Scientists study the interactions of different populations in an ecosystem's community. This helps them to understand what makes an ecosystem grow.

  • The Blackland Prairie has populations of armadillos and badgers. It has little bluestem grass and Indian grass. It has elm trees. It also has pond algae and soil bacteria.

  • Most people are satisfied with just identifying the populations around them. Scientists, however, want to know how populations interact. Scientists investigate the activities of animals, plants, fungi, protists, and bacteria in the ecosystem. They want to know which animals prey on others. Which animals eat plants? Which insects eat crops? They are interested in how bacteria and fungi make the soil fertile. All these questions need to be answered to understand how an ecosystem stays healthy

  • Scientists have to do more than study individual organisms or even individual populations in the ecosystem. They have to study the interactions of all the populations in an area. All the populations living in an area make up a community.

  • What Are Niches and Habitats?

    • The place where an organism lives is called its habitat. The chorus frog's habitat is in the scattered ponds of the Blacklands.

      The red bat's habitat is above the ground. During the day it hangs from tree branches like a red leaf. At night it streaks through the air looking for food.

  • Each species in an ecosystem also has a role or place in the activities of its community. The role of an organism in the community is its niche.

  • A species' niche includes many factors. It includes what a species eats and what eats that species. It includes the kind of environment the species needs to live in. It even includes whether the species is active by day or night.

  • No two populations can have the same niche. Why is this true? To have the same niche, two populations would have to eat the same foods and be eaten by the same predators. They would have to live in the same space and reproduce in the same ways. They would have to grow under the same temperature, moisture, and light conditions, get the same diseases, and look and behave exactly alike. They would have to be identical! No two populations are identical though, so no two populations have the same niche.

    • Scientists study the habitats and niches of organisms in a community. They do this to see if the community is healthy or in trouble.

      The horned lark has its niche on the prairie.

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