What Do We Know? 1. All living things need water to survive. 2. All living things grow, develop and reproduce. 3. Some living things breathe. 4. All living things have a habitat. 5. All living things adapt to their environment. 6. All living things compete for resources. 7. Some organisms live together. 8. Organisms interact in different ways.

Describe life in a Saguaro cactus:

Many species live on, in or around the cactus. Hawks live in a nest Owls live inside the cactus. Rattlesnake looks around the cactus for food. Bats feed on the nectar from the cactus’s flowers. Each organism has unique characteristics. These characteristics help the organism survive in this environment.

I. Adapting to the Environment A. Natural Selection 1. Natural Selection is a process by which characteristics that make an individual better suited to its environment become more common in a species. 2. Natural selection results in adaptations.

A. Natural Selection 3. Adaptations are behaviors and physical characteristics that allow organisms to live successfully in their environments. 4. Over time, poorly suited characteristics disappear from the species.

B. Niches 1. Every organism has a variety of adaptations that are suited to its specific living conditions. 2. The role of an organism in its habitat or how it makes its living is called its Niche.

B. Niches 3. A niche includes: type of food, how it obtains the food, what eats it, and how the organism reproduces and conditions to survive.

II. Types of Interactions C. Competition 1. Competition is the struggle between organisms to survive as they attempt to use the same limited resources. 2. An ecosystem has limited food, water and shelter.

Specialization of Species 3. How do species coexist? Organisms must have adaptations that enable them to reduce competition in order to survive. Organisms “specialize” in their role/niche to survive.

D. Predation 1. An interaction in which 1 organism kills another for food is called predation. 2. The Predator does the killing while the Prey is killed. 3. Predators and Prey have adaptations for survival.

E. Symbiosis 1. Symbiosis is a close relationship between 2 species that benefits at least 1 of the species.

Mutualism 2. Mutualism is a relationship where both species benefit. Example = 1. Bats and the Saguaro Cactus 2. Acacia trees and Stinging Ants

Commensalism 3. Commensalism is a relationship in which 1 species benefits and the other is neither helped nor harmed. Example = 1. Hawks build a nest in the cactus 2. Owls living in the cactus 3. Not very common in nature.

Parasitism 4. Parasitism involves 1 organism living on or inside another organism and harming it. a. the organism that benefits is Parasite b. the organism that is harmed is the Host Example = 1. Fleas, ticks and leeches 2. Tapeworms 3. Mites living in the ears of Moths

Parasite/Host

What did We Learn? 1. Organisms adapt to their surroundings. 2. Natural selection is a process in which species become better suited to their environment. 3. Organisms have niches, which are their roles. 4. Some organisms are predators. 5. Specializing can reduce competition. 6. Organisms use defense strategies to avoid predators. 7. Some organisms live together in symbiotic relationships type of Symbiosis include: Mutualism, Commensalism and Parasitism.