1 / 11

Bellringer

Bellringer. List 3 reasons why a population might decrease in size. Population. Limiting Factor : A factor that causes population growth to decrease 2 Types: 1. Density-dependent: Factors that depend on the size of the population

susanb
Download Presentation

Bellringer

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Bellringer • List 3 reasons why a population might decrease in size

  2. Population • Limiting Factor: A factor that causes population growth to decrease • 2 Types: • 1. Density-dependent: Factors that depend on the size of the population • Only become limiting when the population density becomes very high • Effects are intensified as the pop. Density increases • 2. Density-independent: Factors that do not depend, or are independent, of the size of the population • Are limiting regardless of the size of the population • Affect allpopulations in similar ways

  3. Limiting Factors

  4. Deforestation • Density-Independent • Human activities • Deforestation; over-hunting/fishing • Effects are harmful on population regardless of size

  5. Predation • Density-Dependent • Predation • The effect of predation intensifies as the population density of predators increases.

  6. Disease • Density-Dependent • Disease • High population densities make the spread of disease easier to transmit

  7. Natural Disasters • Density-Independent • Natural Disasters • Hurricane, tornado, flood, severe drought • Equally devastating to populations regardless of size

  8. Competition • Competition: • More members of a population = Less Available resources = More competition • Less members of a population = More available resources = Less competition

  9. Parasitism • Density-Dependent • Parasitism • High densities make it easier for parasites to find hosts, and spread diseases

  10. Severe frost • Density-Independent • Weather • Extremely hot/cold temperatures; frost • Adversely effects all populations regardless of their size.

  11. Creative Writing • Each group will work together to develop the beginning of a story. • Introduce your characters, setting, problem (limiting factor), and size of population in that characters community • Pass your story to the next group 2. Each group will read the introduction of the their new story, and: • Explain how the characters are being affected by the problem introduced in Part 1 (what fears/concerns does this organism have for his/herself and his population • Pass your story to the next group 3. Each group will read their new story, and write its ending: • Explain what happened to the character and his/her population as a result of the problem; will they be doing anything to re-build their population? • Explain the impact this problem had on the overall population size?

More Related