1. Ecology Notes Materials taken from: http://www.regentsprep.org/Regents/biology/biology.cfm

2. Living VS. Non-Living Complex organisms, such as humans, require many systems for their life processes. Less complex living things may lack the complex systems of more complex organisms, but they still carry on the basic life activities. While non-living things may carry on some of these life processes, they do not carry on all of them, or these activities do not interact in a manner allowing the non-living thing to reproduce itself. The components of living things in humans and other organisms, from organ systems to cell organelles, interact to maintain a balanced internal environment. This balanced internal environment is called dynamic equilibrium or homeostasis. To successfully accomplish this, organisms possess many control mechanisms that detect internal changes and correct them to restore the internal balance of the organism. If an organism fails to maintain homeostasis, this may result in disease or death. Non-living things possess few control mechanisms to maintain homeostasis.

3. Living VS. Non-Living Living things carry out almost all the life processes or activities. These life processes include digestion, respiration, circulation, excretion, locomotion, immunity, coordination, and synthesis. Non-living things are incapable of carrying out at least one or more of the life processes. The sum of the energy used in all the life processes represents the metabolism of the organism. Homeostasis: The ability to carry on the life processes allow a living thing to maintain dynamic equilibrium or homeostasis with their surroundings. Homeostasis is a state of balance or steady state between a living thing and its environment. Homeostasis in an organism is constantly threatened. Failure to respond effectively to a failure of homeostasis can result in disease or death.

4. Diversity Population Diversity The greater the diversity, or number of different species of organisms in an ecosystem, the ecosystem is more stable and likely to last. These ecosystems contain many different kinds of organisms carrying on a variety of different nutritional modes. Organisms can be categorized by the function they serve in an ecosystem. Each species in an ecosystem has a role for which it is best suited. In general, no two species have the same role in an ecosystem. This allows different species to coexist successfully and helps maintain the stability of the ecosystem. Ecosystems are stable due to the interactions among the many different populations. These interactions contribute to the overall maintenance and continued existence of the ecosystem.

7. Pond Ecosystem

9. Stable Ecosystems In order for an ecosystem to sustain life certain conditions must be meet.

10. Stability of Ecosystems… The greater the number of different populations that interact within an ecosystem, the more stable and self- sustaining the ecosystem becomes. The number of different population within an ecosystem is something referred to as biodiversity. Theses interactions contribute to the overall eminence of the ecosystem.

11. Niche

12. Niche…