1. Biotic Factors That Affect Populations
Gaiser Life Science

2. Know Evidence Page # What biotic factors affect an ecosystem?
“I don’t know anything.” is not an acceptable answer.
Use complete sentences.
Evidence
After listening to the PowerPoint lecture, come back here and list evidence to explain why your answer to the above question is or is not a good answer. You may also use other outside sources to help you respond.
Choose an animal and create a web to show how the biotic factors will affect that animal and its habitat.
Page #

3. Biotic Factors That Affect Populations
Information
Clarifying ?s
- the living parts of an ecosystem
biotic factors
Example: plants, animals, bacteria, fungi
6 types of biotic factors
1. Predation - one animal hunts and kills another for food
Examples: lions, tigers, bears, humans
Effect on population - Good hunters lower the population. Poor hunters allow the population to increase.
2. Competition - the struggle between organisms to survive in a habitat with limited resources
Example: Taller trees casting shade on shorter trees in a dense forest
3. Humans
A. Habitat destruction - major cause of extinction - forests cut down to build human homes
B. Poaching - illegal killing or removing of animals from an area
Examples: tropical fish, ivory, exotic birds, rhino horns
C. Pollution - Settles into water, air, and soil. Is absorbed by plants and animals. Can affect food chain and cause birth defects.
Example: Birds with malformed beaks
4. Disease - Infectious diseases can spread from one organism to another OR species to species!
Example: Flu, cold, smallpox, polio, HIV
5. Carrying capacity - too many organisms - not enough resources
6. Plants - type of plant determines what can live in area.
Example: Lion on the Savannah
Page #
Summary:

5. Biotic Factors That Affect Populations
Information
Clarifying ?s
- the living parts of an ecosystem
biotic factors
Example: plants, animals, bacteria, fungi
6 types of biotic factors
1. Predation - one animal hunts and kills another for food
Examples: lions, tigers, bears, humans
Effect on population - Good hunters lower the population. Poor hunters allow the population to increase.
2. Competition - the struggle between organisms to survive in a habitat with limited resources
Example: Taller trees casting shade on shorter trees in a dense forest
3. Humans
A. Habitat destruction - major cause of extinction - forests cut down to build human homes
B. Poaching - illegal killing or removing of animals from an area
Examples: tropical fish, ivory, exotic birds, rhino horns
C. Pollution - Settles into water, air, and soil. Is absorbed by plants and animals. Can affect food chain and cause birth defects.
Example: Birds with malformed beaks
4. Disease - Infectious diseases can spread from one organism to another OR species to species!
Example: Flu, cold, smallpox, polio, HIV
5. Carrying capacity - too many organisms - not enough resources
6. Plants - type of plant determines what can live in area.
Page #
Summary:
Example: Lion on the Savannah

6. This PowerPoint was created by Tim Paterek from Charlene Shea’s lecture notes. All pictures came from Google Image Search. To fall within the Fair Use Guidelines, this PowerPoint must be used within the confines of the classroom and may not be published back onto the Internet unless the pictures are removed.