1. 3/6 Daily Catalyst Pg. 28 Carrying Capacity
1. In a particular food web from the coniferous forest biome, the first trophic level contains 5,987 kcals. How much energy would you expect to be at the fourth trophic level?
2. Describe the type of symbiosis that is commensalism.
3. Predict the impact of a disturbance that affects the primary consumers of an ecosystem.
Precipitation, evaporation, transpiration and condensation B
today

2. 3/6 Birthday fun!

4. 3/6 Class Business Pg. 29 Carrying capacity
Quiz #7 on Friday
Lab on Friday
Lab moved to next TUESDAY (after the PLAN test)
Outside, if weather permits (bring jacket)
Paper due Friday, March 6th
Must be printed out
Must include rubric
3 test grades
3rd, nine-week grades due March 13th

5. 3/6 Class Business Pg. 29 Carrying Capacity
Daily Catalyst
Class Business
Activity
Carrying capacity notes
Quiz #7

6. 3/6 Objective Pg. 29 Carrying Capacity
Today, we will study the carrying capacity of an environment and factors that influence the carrying capacity.

7. Video clip

8. What determines population?
Why can’t we have…10,000 students here at Bonnabel? Give specific reasons.
We will reach the capacity of the school!
Space
Books
Teachers
Supplies
Student behavior
These are called limiting factors!
Limit? These factors limit the population

9. On the provided graph paper, graph the following scenario.
Let’s graph!!
On the provided graph paper, graph the following scenario.

10. The deadly Ebola virus
Ridel and Eva are working together on a research project. They decided to study the Ebola virus. They specifically studied the growth rate of the Ebola in certain environments.

11. Ebola Virus vs. Time X = Time (wks) Y = # of virus 500 450 400 350 300
250
200
150
100 50
X = Time (wks)

12. At the beginning of the experiment (week 1), Ridel and Eva start off with 25 Ebola viruses in petri dishes.

13. Ebola Virus vs. Time X = Time (wks) Y = # of virus 500 450 400 350 300
250
200
150
100 50
X = Time (wks)

14. The first few weeks consist of the viruses invading the healthy host cells, integrating their DNA. Viral replication is slow at first. At the end of the 2 ½ week, viral numbers are 50. At the end of the fourth, week, viral numbers are 75.

15. Ebola Virus vs. Time Y = # of virus X = Time (wks) 500 450 400 350 300
250
200
150
100 50
X = Time (wks)

16. Ridel and Eva take a little bit of a break and check the petri dishes after six weeks. The viral numbers are only 100. They are worried their experiment is flawed.

17. Ebola Virus vs. Time Y = # of virus X = Time (wks) 500 450 400 350 300
250
200
150
100 50
X = Time (wks)

18. Over the next weeks, the Ebola viruses grow rapidly in the petri dishes. The petri dishes are filled with human living cells and the cells have plenty of energy sources. At the end of seven weeks, the number of viruses have increased to 175 .

19. Ebola Virus vs. Time Y = # of virus X = Time (wks) 500 450 400 350 300
250
200
150
100 50
X = Time (wks)

20. Now that they have seen significant growth, Ridel and Eva know they have a good experiment. Over week 8 and week 9, growth jumps to 250 and 375.

21. Ebola Virus vs. Time Y = # of virus X = Time (wks) 500 450 400 350 300
250
200
150
100 50
X = Time (wks)

22. At week 10, the population grows to 450 Ebola cells
At week 10, the population grows to 450 Ebola cells. There are still 6 more weeks left in the experiment. Ridel and Eva expect the Ebola virus to keep reproducing the entire 16 weeks!

23. Ebola Virus vs. Time Y = # of virus X = Time (wks) 500 450 400 350 300
250
200
150
100 50
X = Time (wks)

24. Eva is so excited about the growth of the Ebola and believes their science fair project is so amazing that Mrs. Ireland is sure to give them an A+. Ridel, on the other hand, is worried that there are not enough human cells. He knows from Environmental Science, that eventually the human host cells will be destroyed by the viruses. Without a living host, the viruses can replicate.

25. Ebola Virus vs. Time Y = # of virus X = Time (wks) 500 450 400 350 300
250
200
150
100 50
X = Time (wks)

26. Since Eva is so sure of their success, she leaves Ridel in charge of the lab as she begins to write their research paper for Mrs. Ireland. Over the next few weeks, Ridel starts to see a decline in Ebola growth.
At week 11, the population dips to 425.

27. Ebola Virus vs. Time Y = # of virus X = Time (wks) 500 450 400 350 300
250
200
150
100 50
X = Time (wks)

28. As another week passes, the population dips to 400
As another week passes, the population dips to 400. Ridel is worried and contemplates calling Eva. He doesn’t want all of the Ebola viruses to die! Mrs. Ireland will never take a project with empty petri dishes!

29. Ebola Virus vs. Time Y = # of virus X = Time (wks) 500 450 400 350 300
250
200
150
100 50
X = Time (wks)

30. Over the remaining couple of weeks, the viruses stay at a population size of 400. Ridel wonders why this happens?

31. Ebola Virus vs. Time Y = # of virus X = Time (wks) 500 450 400 350 300
250
200
150
100 50
X = Time (wks)

32. Ebola Virus vs. Time Y = # of virus X = Time (wks) 500 450 400 350 300
250
200
150
100 50
X = Time (wks)

33. Key Point #1: Carrying Capacity
The maximum population size that a particular environment can support.

34. Continuing for a period of time
Key Point #2: Disturbances
Cause damage to the biological community
Examples: fire, drought, storm, earthquakes (natural disasters), and human activity etc.
Following a disturbance, how do we expect the population to grow? As long as the soil is able to support life, with bacteria, life can return. We expect populations to grow exponentially because there are plenty of resources and the populations is trying to restore balance. Can this type of growth be sustained? No this type of growth cannot be sustained because as we know, there are limits to everything!
Sustained?
Continuing for a period of time

35. A more realistic image
If I only showed you the exposed graph, most of you would say this is exponential growth. So far, you are correct. In the beginning, we see early rapid growth. Click box. Eventually the population growth will start to slow down as resources become limited. The population growth will stabilize. Now this looks like a logistical curve.

36. Examining Logistic Population Growth
As the population levels out, this represents carrying capacity. Have a student define carry capacity once again. This is the population size (look at the y-axis, it is in population size (N), that the environment can safely hold.

37. Are Carrying capacities fixed?
Why does the carrying capacity vary?
Different climates
Abiotic and biotic factors vary
Environments can change
How?
Disturbances
Human activity
Because resources in environments will differ per climate what abiotic factors are present to provide for the biotic factors. Discuss disturbances. Fires, famine, earthquakes, hurricanes, etc.

38. Carrying Capacity
Key Point #3: Limiting factors affect the carrying capacity
Limiting Factors:
1. Water
2. Food
3. Shelter/space
4. Competition
Food, water, space, competition

39. Food and water availability- when the food/water supply runs low, a population can’t continue increasing or organisms will starve
Example: elephant
herd looking for
food during dry
season
Limiting factors

40. Living space- if the space becomes too crowded, the population can’t continue increasing
Example: large buffalo
herd in a small park

41. Competition- if another species with the same habitat as the population enters the ecosystem and competes for resources, the population(s) won’t be able to grow
Example: Lion and
cheetah
Bring up symbiosis and the fact that competition is (-/-) relationship

42. Stop, and Check
What might cause a population to reach carrying capacity? _______ ________
Limiting factors
LIMITING FACTORS

43. Not all limiting factors influence a population the same way.
Some limiting factors are effected by the size of the population and some are not.
Examples?

44. Graph’s predict birth and death rates
When the population is below its carrying capacity, there is room to grow so this is point B. When the population is above its CC, the population will decrease, point D. The population wants to be at its carrying capacity.

45. Carrying Capacity
Eventually the population becomes stable

46. Key Point #4:
-Population increasing= birth rates _______ over death rates
-Population decreasing= birth rates ________ over death rates
-Population is constant= birth rates ______ death rates
Higher
equal

47. Quick Class Practice
1. In what three years does population size most exceed carrying capacity?
2. Why does the population decrease after 1850?
3. What is this population’s carrying capacity?
1850, 1875, 1910
It was above the carrying capacity and couldn’t support the population
1.5 million people

48. The main point
Above carrying capacity  population will decrease (death rate is higher than birth rate)
Below carrying capacity  population will increase (birth rate is higher than death rate)
Levels off at the carrying capacity  population remains stable (birth rate=death rate)
Have students turn and talk about this with a classmate.

49. Quiz #7
Directions: Silently and independently complete quiz #7. Turn your quiz into the basket and start working on your symbiosis worksheet. This is homework and is due MONDAY in the basket!
Noise: 0 (SILENT)
Time: 12 minutes

50. Remember good behavior and respect**
Monday, 3/9
I will be gone Monday
You will work on a sub packet. Quiz #7 quiz corrections can be completed to boost your grade! Sub packets are due Tuesday. No exceptions and no late passes. Remember, grades are due next Friday. Sub packets are worth 3 test grades!
Remember good behavior and respect**

51. Practice Time
Directions: Using your notes and the book, complete the following problems on page This is homework if you do not finish and is due tomorrow in the basket. Answer these question on Pg. 18 Carrying Capacity
1, 3, 4, 7, 9, 10, 11, and 16
Time: 12 minutes
Noise: 1 (partner)

52. Exit Ticket #5 Name: ____________ Per: 1 date: 2/9 Score: _____/4
1. Define Carrying Capacity
2. If the population is above carrying capacity, what does this mean for birth rates?
3. What happens when a population reaches carrying capacity?
4. True/false, is the population size is constant, it means no births or deaths are occurring.

53. 1. Define Carrying Capacity:
The most organisms an environment can support
2. If the population is above carrying capacity, what does this mean for birth rates?
Birth rates are greater than death rates
3. What happens when a population reaches carrying capacity?
It cannot grow anymore, because the environment cannot support the population
4. True/false, is the population size is constant, it means no births or deaths are occurring.
False, means births= deaths