1. Warm-up
Explain what symbiosis is.
Homework: Page 97 no. 1-6

2. Warm-up
Make a Venn-diagram to compare and contrast Mutualism and Commensalism

3. Ecology

4. Ecological Succession
Communities replace each other
Process of Succession
May take 100’s or 1000’s of years
Involves intermediate or serial communities
Starts with a Pioneer species.
climax community: is a relatively stable, almost permanent, community that is determined by an area’s climate.

5. Ecological Succession
Types of Succession
Primary occurs in areas that have not supported communities before
ex. Communities on bare rock
Begins with pioneer species
Serial communities are replaced until climax is reached
Secondary occurs in areas that have supported communities

6. Essential Questions
The first organisms to invade an area and start the process of succession are called?
Pioneer species
If a farmer abandons a field and lets it grow naturally, is this an example of primary or secondary succession?
Secondary because at one time the field supported living organisms

7. Warm-up Prepare for quiz: Primary succession Secondary succession
Habitat
Niche
Pioneer community
Climax Community
Marine succession - organisms

8. Quiz
1.The first species to inhabit a disturbed natural area, are usually called ___________ species.
2. A stable community that is unlikely to undergo many changes is known as a _________ community.
3. The development of successive communities on a newly formed volcanic island is known as ____________ succession.
4. The North American Redwood Forests are examples of a ____________ community.
5. Succession that happens on an old farmland is known as __________ succession.
6. Three species of warbler that live in one tree, has the same ____________ but not the same ______________.
7. The full range of conditions in which an organism lives and uses the conditions where it lives is known as the organism’s ___________.
8. When a whale dies and sinks to the bottom of the ocean floor, it attracts s______________ and d____________ which will be responsible for succession.

9. Warm-up
List at least three (general) characteristics you could use to describe a population in any ecosystem.

10. Warm-up: Inquiry Activity page 118
In each generation, only half of the population will be female.
6 offspring in year one, 18, 54, 162, 486 in year 5.
10 years: 120,000 rabbits
20 years: 7 Billion rabbits
Natural predators, diseases and limited food and water limit populations. Not all offspring survive, some adults do not reproduce.

11. Brain teaser
What would happen to the plant population once the rabbits start reproducing?
Starts to decrease, because rabbits eat them
If the rabbits died because there weren’t enough plants to eat, what would happen to the plant populations? Why?
Plant populations size increases; fewer rabbits are eating them.

12. Warm-up If population density = Number of individuals / unit area:
Suppose there are 150 bullfrogs living in an area of 3 square kilometers. What is the density of this bullfrog population?
Estimate the population density of people in this classroom. (Estimate area).

13. Principles of Population Growth
How fast do populations grow?
Not linear
Exponential growth (page 121)
Limits of the environment
Limiting factors stops unlimited growth
Ex food, space
Carrying capacity : the number of organisms of a species that an environment can support.

14. Warm-up Draw a graph that shows exponential growth.
Draw a graph that shows that population growth stabilized (logistic growth).

15. Population Growth Growth Curves S-Curve
J-Curve
Shows exponential growth
S-Curve
Shows that population growth stabilizes

16. Population Growth
Carrying capacity the max number of individuals that an environment can support
Limiting factors determine an area’s carrying capacity by limiting population size
Density dependent factors- food, salt concentration, oxygen
Density independent factors- weather, fire, natural disasters.

17. Warm-up 1. How has the size of human populations changed over time?
2.Why do population growth rates differ in countries throughout the world?
ANS.1 Tends to increase with time.
ANS.2 Because of differences in birthrates, death rates and age structures in different countries.

18. BIOMES

19. Biomes
Aquatic based on salinity of the water, takes up most space on earth
Marine: most salinity
Estuary: intermediate salinity
Freshwater: least salinity

20. Biomes Terrestrial based on types of climate patterns
Tundra: extremely cold temperatures; precipitation as snow
Adaptations- animals with thick fur, dwarf plants
Permafrost- layers of permanently frozen ground
Taiga: long severe winters and short dry summers
Adaptations- animals may migrate
Characterized by evergreens

21. Biomes Terrestrial (cont.) Desert: hot and dry
Adaptations- organisms must have ways to conserve water ex. nocturnal animals
Characterized by having lots of reptiles
Grasslands: experience a wet and dry season
Adaptations: lots of grazing animals
Soil rich with humus, grasses form a continuous layer of sod

22. Biomes Terrestrial (cont.)
Deciduous Forest: abundant precipitation and 4 distinct seasons
Adaptations- trees lose leaves in winter
Tropical Rain Forest: warmest and wettest biome, found near the equator
Adaptations- most animals live in the canopy to reach sunlight
Forest characterize by layers

23. Biomes of the World

24. Critical Questions
Which aquatic biome contains a mixture of salt water and fresh water?
Which biome do we live in?
Succulent plants which store water in their tissues may be found in what biome?
In which biome would you find the most diversity of plant and animal life?