1. Interdependence of Living Systems
Parts of this Powerpoint are highlighted or in a different color font to assist dyslexic students.

2. Vocabulary
Homeostasis – process used by the body internally to stay stable externally
Negative feedback – a way to stay stable using a process that is turned off by the condition it produced

3. Hormone – chemical produced by endocrine gland that affects the activity of a tissue or organ
Diffusion – process that allows substances to move back and forth through a cell membrane

4. Osmosis – the diffusion of water molecules through a selectively permeable membrane
Turgor pressure – pressure of water against the cell wall of plant cell

5. The Body must stay in equilibrium
Homeostasis is the process by which the body keeps all systems working properly.
Must combat external forces to maintain equilibrium.
Negative feedback systems keep equilibrium.
Example: sweating and shivering

6. Example 1
Energy used by the body comes from breakdown of glucose through a chemical reaction
The level of glucose is controlled by hormones in the endocrine system
One hormone is insulin

7. Example 2
Homeostasis requires the amount of water in a system to be regulated
Cells (plant and animal) have a membrane that allows substances to move back and forth
This is called diffusion – in which a high concentration of molecules moves into an area where the concentration is lower

8. Turgor Pressure Plant cell walls allow for expansion
As water moves in the cell membrane expands against
the cell wall
The pressure is called turgor pressure and is what helps
give the plant shape and firmness

9. Interactions Among Living Things

10. Niche
Each organism has unique characteristics that allow it to serve a specific purpose in the ecosystem – that is its niche
This niche includes how the organism interacts with other organisms
There are 3 major types of interactions:
competition
predation
symbiosis

11. Competition
Different species can share same food needs but not the same niche
If they do occupy the same niche one of them will die off
Ecosystem has a limited amount of food, water, and shelter
the struggle to survive in a particular habitat is competition

12. Predation
The hunting and killing of another animal for food is predation
The organism doing the killing is the predator while the animal being killed is the prey
Many animals have developed some type of adaptation to help it catch and kill prey
Others have developed adaptations to avoid being caught
Predation has a major effect on the size of a population
A population size grows and reduces depending on food availability & disease

13. Symbiosis There are 3 types of symbiotic relationships
between organisms
These are :
mutualism
commensalism
parasitism

14. Mutualism
This is relationship in which both species benefit is mutualism
Commensalism
A relationship in which one species benefits and the other one is neither helped nor harmed

15. Parasitism
This relationship is one in which one organism lives on or inside another organism and harms it
The one that benefits is called a parasite and the host is the one that is harmed
Teacher Note-There is a parasite that lays its eggs in a human when they are bitten by a mosquito in Africa. When the parasite goes to reproduce it travels down to the legs and feet. There the animal lays its eggs. When they hatch the worm bores a hole through the skin. A doctor uses thread to wind the worm around the thread as he/she draws out the worm.