ECOLOGY Midterm Review Topics and Study Guide

ECOLOGY Midterm Review Topics and Study Guide:

Ecology:

Ecology is the study of how living organisms interact with both each other and their environment. An ecosystem is a particular place where we see such interactions.
For example, a pond is an ecosystem where we might see fish, insects, ducks, and plants interacting with each other and being affected by the temperature, the pH of the water, the amount of oxygen, and the amount of space and shelter available. There are interactions between both the living and the nonliving.
The living parts of an ecosystem are called biotic factors, such as the plants and animals that live there.
The nonliving parts of an ecosystem are called abiotic factors. Sunlight, soil type, minerals, water, pH, temperature, and oxygen are all examples of abiotic factors.

Diversity in the Ecosystem:

Within an ecosystem, there is a lot of diversity among living things. Diversity, or variation, increases the chances of survival within a population. If there are variations among individuals, chances are that someone will be able to survive an environmental change
The diverse populations of living things interact and compete with each other. Organisms compete for both biotic and abiotic factors. Organisms compete for mates to reproduce with and food (biotic factors). Organisms also compete for space, shelter, water, and sunlight (abiotic factors).

Carrying Capacity:

Organisms have the capability to reproduce infinitely, but because there is only a finite (limited) amount of resources in nature, ecosystems can only support a certain amount of organisms.
The maximum number of organisms that can be supported by an ecosystem is called the CARRYING CAPACITY.
If a population goes beyond the carrying capacity, then there will not be enough resources for everyone to survive. Organisms will run out of space, shelter, food, or water, and organisms will not survive. The population of a species cannot go beyond the carrying capacity of the ecosystem, because the ecosystem will run out of finite resources.

Roles in an Ecosystem:

Producer/Autotroph- Producers are organisms that make their OWN food by using energy from the sun. PLANTS are the producers of the ecosystem. Another name for a producer is an autotroph- an organism that makes its own food. Plants make their own food by the process of photosynthesis. Plant food is called glucose.
Consumer/Heterotroph- Consumers must EAT other organisms to get food for energy. All animals that eat are consumers- this includes insects, birds, cows, and humans. All consumers are heterotrophs. A heterotroph is an organism that relies on other organisms to get organic nutrients.
Predator- The hunter. (Example- WOLF)
Prey- The hunted. (Example- RABBIT) Remember, plants are NOT prey, because plants do not try to run away from, or hide from organisms that eat them.
Parasite- An organism that disrupts the homeostasis of another organism by stealing their nutrients.
Host- An organism infected by a parasite. Homeostasis is disrupted.
Decomposers-Bacteria and fungi are decomposers. Decomposers breakdown DEAD organic material. Their role in the ecosystem is to recycle nutrients back into the soil. Without decomposers, the ecosystem would not be able to exist.

ECOLOGY Practice Midterm Questions!