7th Grade Chapter 21 - Populations and Communities
Section 1 - Living Things and the Environment
In this section students will learn about the needs that must be met by an organism's surroundings. They will identify biotic or living factors and abiotic or non-living factors: water, sunlight, oxygen, temperature, and soil in different parts of a habitat. Students will then identify and describe the levels of organization within an ecosystem. We start with a single organism, next a "population" of that particular species/organism, then communities of all the different populations living and interacting together, and finally an ecosystem which is composed of all the living and nonliving factors of a particular area.
Section 2 - Studying Populations
This section will teach students about the different methods ecologists use to determine the size of a population: direct and indirect observations, sampling, and the mark-and-recapture method. Students will look at different factors that can effect the size of a population and learn about how some of those factors can limit a populations growth.
"Cats" in a Pond Lab
The "cats" students will be using for this lab really represent turtles in a pond. Students will use these cats to imitate the mark and recapture method used by ecologists to monitor the size of a population of organisms.
Section 3 - Interactions among Living Things
For this section students will be broken up into 6 groups of 4-5 students to research and present the six types of interactions among organisms: Competition, Predation, Symbiosis, Mutualism, Commensalism, and Parasitism. Students will also review how organism’s adaptations help them to survive.
Section 4 - Changes in Communities
In this short section students will learn the difference between primary and secondary succession.
