Chapter 24

Section 1- Living Earth The difference in the Earth and other plants is that the Earth has an abundance of living organisms.  Biosphere  Part of the Earth that supports life.  Includes top portion of the Earth’s crust and all the water that covers Earth’s surface.  Biosphere contains FIXED amounts of water, Carbon, nitrogen, oxygen And other minerals

 Ecosystem- consists of all of the organisms living in an environment, as well as nonliving parts of that environment.  Ecology- the study of interactions among organisms and their environment.

 Population  Organisms in an ecosystem that belong to one species.  Ex. A population of deer  Community  All the populations in an ecosystem  Ex. Population of deer, population of turkeys, population of squirrels all living together  Habitat  The place in which an organism lives  Ex. The ocean is the shrimps habitat  Ex. The burrow a chipmunk digs under a patio stone

Section 2- Populations  Limiting Factor  Anything that restricts the number of individuals in a population.  Ex. Availability of food, water, living space, mates, nesting sites.  Carrying Capacity  The largest number of individuals of one species that an environment can support and maintain.

Section 3- Interactions Within Communities  Producers  Organisms that use an outside energy source to make energy-rich molecules  Ex. All green plants  Consumers  Organisms that CANNOT make their own energy-rich molecules.  Obtain energy from eating other organisms.

4 Types of Consumers  Herbivores- Plant eaters like deer and rabbits.  Carnivores- Animals that eat other animals. (meat eaters)  Ex. Frogs and Spiders eat Insects.  Omnivores- Eat mostly plants and animals.  Ex. Pigs and Humans  Decomposers- Eat dead organisms  Ex. Worms  Competition occurs when two or more organisms seek the same resource at the same time.

Type of Consumer??

 Symbiosis  A close relationship between species.  Organisms that live together and share resources.  Mutualism  A symbiotic relationship in which BOTH species BENEFIT  Ex. Lichens  Commensalism  A symbiotic relationship in which one partner BENEFITS but the other is NOT AFFECTED.  Ex. Clown fish and sea anemones  Parasitism  A symbiotic relationship in which one organisms BENEFITS but the other is HARMED.  Ex. Roundworms

Food Chains  Food Chains- The feeding relationships among the organisms in a population.

 Niche- how an organism survives in its environment.  The role a species plays within a community  How it obtains food, shelter, finds a mate, avoids danger.