Download 3 - Edmodo

MARY WARD CATHOLIC SECONDARY SCHOOL
Centre for Self-Directed Learning
Grade 9 Academic Science (SNC 1D1)
Unit # 3: BIOLOGY – Interactions in Ecosystems
Unit Last Revised: August 2013
ACTIVITY DESCRIPTION
TIME
EVALUATION
CATEGORY
MARKS
Activity A - Interactions in
Ecosystems
1. Biotic Interactions
1.0 hr
Activity B – Carrying Capacity and
Limiting Factors
1. Population Growth
2. Limiting Factors
1.5 hr
Activity C – Case Study – Hares and
Wolves
2.0 hr
Rubric
Inquiry/
Application
/22
/16
Activity D - Unit Assessment
1.0 hr
Rubric
Knowledge
Level
Total Activity Time:
5.5 hr
Expectations: These are the things you will be learning in this unit:
Overall
 Demonstrate an understanding of the dynamic nature of ecosystems, including the relationship between
ecological balance and the sustainability of life
 Investigate factors that affect ecological systems and the consequences of changes in these factors
Understanding Basic Concepts
 Compare and contrast biotic and abiotic characteristics of sustainable and unsustainable terrestrial and aquatic
ecosystems
 Describe the limiting factors of ecosystems and explain how these factors affect the carrying capacity of an
ecosystem
Developing Skills of Investigation and Communication
 Use appropriate terminology related to sustainable ecosystems
 Interpret qualitative data, communicate the results graphically, and extrapolate from the data
Page 2 of 16
Activity A – Interactions In Ecosystems
1. Biotic Interactions
Now that we know about different components in an ecosystem, we can investigate how these components
interact (or work together) with each other. Organisms in a community interact with one another in many ways
and sometimes are dependent on each other. Three interactions we will look at are competition, predation and
symbiosis.
□
□
in your Investigating Science 9 textbook read pages 36-42
view the following video on Edomodo.com in Unit 3:
Competition, Predation, and Symbiosis
□
answer the following in your notebook:
1) How do similar species that feed on the same prey coexist in an area together and avoid competition?
2) Describe an example not from your textbook of an adaptation an organism uses to avoid being eaten.
3) What is symbiosis? Describe the 3 main types of symbiosis and an example for each.
Activity B – Carrying Capacity and Limiting Factors
1. Population Growth
Depending on what resources are available to organisms in an ecosystem, populations can experience different
types of growth. Below you will investigate 3 types of growth before moving on to the learning check box.
EXPONENTIAL GROWTH (J-CURVE):
Under ideal conditions – where there are few or no limiting factors – a population starts off slowly (to get
established in the ecosystem) and continues to increase exponentially (very rapidly).
Graph a line graph with the following data to obtain a J-curve:
J –Curve Graph
0
0
1
5
2
10
3
20
4
35
5
65
6
100
POPULATION
Time (years)
Population of
deer
TIME (YEARS)
Page 3 of 16
THE BOOM AND BUST CURVE:
Some populations go through periods where their numbers suddenly increase dramatically for a few generations
and then go back to normal. Insects are a common species that go through tremendous growth for a few
weeks, followed by a sudden collapse. This state can be described by means of a boom (sudden increase) and
bust (sudden decrease) curve.
Graph a line graph with the following data to obtain a Boom and Bust curve:
Boom and Bust Graph
0
0
1
5
2
20
3
55
4
70
5
50
6
25
POPULATION
Time (years)
Population of
flies
TIME (YEARS)
The S-Curve:
When populations are introduced into a new ecosystem they will start off as a J-Curve but after a while
population numbers slowly level off (plateau) due to the limiting factors (for example, amount of food, space).
When a population levels off, it is said to have reached the carrying capacity of its environment – the maximum
number of individuals the ecosystem can support without reducing its ability to support future generations of
the same species.
Graph a line graph with the following data to obtain an S-curve:
S –Curve Graph
0
0
1
5
2
30
3
55
4
55
5
60
6
60
 indicate the carrying capacity on your graph using a line
(hint: refer to fig 1.40 on pg 40)
POPULATION
Time (years)
Population of
deer
TIME (YEARS)
□
□
Obtain subject teacher’s signature to check your graphs  teacher signature:____________________
in your Investigating Science 9 textbook read pages 40-41
Page 4 of 16
2. Limiting Factors
As seen in the previous activity, ecosystems have a carrying capacity when certain factors limit the growth of
populations. For example, availability of resources such as food, water and space can be limiting factors that
prevent a further increase in the number of organisms. Limiting factors can be abiotic and biotic.
□
□
in your Investigating Science 9 textbook read pages 41-42
view the following video on Edmodo.com in Unit 3:
Populations Biotic Potential
□
answer the following in your notebook:
1) In a table, categorize different limiting factors as abiotic and biotic.
Page 5 of 16
Blank Page for Double-Sided Printing
Page 6 of 16
Activity C – Case Study – Hares and Wolves
 Hand in for evaluation
Complete the Case Study – Hares and Wolves. Once you have completed it hand it in to your teacher with the
evaluation rubric.
PART A
Imagine the following scenario:
One winter, an ice bridge is formed across a large lake to an island. A pair of hares, one male and one female, make their
way across the ice to the island. They end up stranded when the ice begins to melt in the spring. There is ample food on
the island; no other hares live there, and there are no predators. The hares find shelter and produce 6 offspring.
Please Note:
a) every spring each pair of hares produces 6 offspring, 3 males and 3 females
b) all of the parents die each winter, only the offspring survive to breed
c) all of the offspring survive through the winter and breed in the spring
d) there is no immigration or emigration
Determine what the population would be in the fall, 5 years later, by filling in Table A. Show All of Your Work!
Table A: Hares before Wolves
Year
Year 0
Year 1
Year 2
Year 3
Year 4
Year 5
Number of Parents
2
6
Breeding Pairs
1
3
Number of Offspring
6
18
Obtain subject teacher’s signature to check your values before moving on  teacher signature: ____________
Graph the population of Hares vs. Time on the following page.
 The numbers you should graph are found in the shaded boxes of Table A.
 Make sure your graphs are appropriately titled and the axes are labelled. Time is the independent variable (on
x-axis) and Population is the dependent variable (on the y-axis).
 Choose an appropriate scale.
 Neatly draw the curve. (5 marks)
Page 7 of 16
Descriptive Title: __________________________________________________________________
Page 8 of 16
PART B
Suppose the following changes are made to the ecosystem in Part A:
a)
b)
c)
d)
e)
in the summer of year 3, a pair of wolves immigrates to the island
each pair of wolves produces 3 offspring a year, alternating male and female
no wolves die during the next 4 years
each wolf eats 22 hares per year
all parent hares are eaten by the wolves before they die naturally
Calculate the wolf population and their consumption of hares in years 3, 4 and 5 by filling in Table B.
Table B: Wolves
Year
Wolves
Breeding Pairs
Year 0
Year 1
Year 2
Year 3
Year 4
Year 5
0
0
0
2
0
0
0
1
Number of
Offspring
0
0
0
3
Total Wolves
Hares Eaten
0
0
0
5
0
0
0
110
Obtain subject teacher’s signature to check your values before moving on  teacher signature: ____________________
Now with introduction of wolves calculate the hare population in years 3, 4 and 5 (in this scenario) by filling in Table C.
In years 3-5, the wolves can eat ANY of the hares, offspring and parents. Therefore, in years 3, 4 and 5:
Hares Left = Total Hares – Hares Eaten
Table C: Hare and Wolf Population
Year
Parent
Hares
Offspring
Hares
Total Hares
Year 0
Year 1
Year 2
Year 3
Year 4
Year 5
2
6
18
6
18
54
8
24
72
Total Wolves
(refer to
Table B)
0
0
0
Hares Eaten
(refer to Table
B)
0
0
0
Hares Left
6
18
54
Obtain subject teacher’s signature to check your values before moving on  teacher signature: ____________________
Plot a graph of the population of Hares vs. Time after Arrival of Wolves
 The numbers you should graph are found in the shaded boxes of Table C.
 Make sure your graphs are appropriately titled and the axes are labelled. Time is the independent variable (on
x-axis) and Population is the dependent variable (on the y-axis).
 Choose an appropriate scale.
 Neatly draw the curve. (5 marks)
Page 9 of 16
Descriptive Title: _________________________________________________________________
Page 10 of 16
DISCUSSION QUESTIONS:
1. What is the name of the growth curve you obtain when you plot the data from Table A? Explain why the hare
population shows this type of growth.
2. What is the name of the growth curve you obtain when you plot the data from Table C? Explain why the hare
population shows this type of growth.
3. What will happen to the wolf population if the hare population continues to decrease? Eventually the hare and wolf
populations will ‘follow’ each other in a pattern that will repeat. Explain what this means.
4. What type of biome does this interaction between wolves and hares occur? (You may have to research this on the
internet). Describe the climate and vegetation of this biome.
Page 11 of 16
5. Wolves need to catch and eat several hares in order to survive because when the wolf eats the hare only 10% of the
hare’s energy is passed on to wolf. What has happened to the 90% of energy that the wolf does not get?
6. Describe in detail 2 types of adaptations hares could develop in order to avoid being eaten by wolves.
7. Besides predators, describe several other limiting factors that could prevent hare populations from increasing. Are
these factors biotic or abiotic?
Page 12 of 16
Case Study – Hares and Wolves Rubric
Inquiry
Graph 1
Graph 2
1
1
2
2
3
3
4
4
5
5
Level 1
Level 2
Level 3
Minimal critical thinking
Some critical thinking and
Thinking and and inquiry skills were used inquiry skills were used to
Inquiry
to interpret data and form interpret data and form
conclusions
conclusions
Level 4
Adequate critical thinking Thorough critical thinking
and inquiry skills were used and inquiry skills were used
to interpret data and form to affectively interpret
conclusions
data and form detailed
conclusions
Q1. What is the name of the growth curve you obtain when you plot the data from Table A? Explain why the hare
population shows this type of growth.
Q2. What is the name of the growth curve you obtain when you plot the data from Table C? Explain why the hare
population shows this type of growth.
Q3. What will happen to the wolf population if the hare population continues to decrease? Eventually the hare
and wolf populations will ‘follow’ each other in a pattern that will repeat. Explain what this means. .
TOTAL INQUIRY MARKS:
1 2 3 4
1 2 3 4
1 2 3 4
/22
Application
Level 1
Application
Makes minimal
connections between
data/research with
science, technology, and
the environment.
Level 2
Level 3
Makes some connections
between data/research
with science, technology,
and the environment.
Makes adequate
connections between
data/research with
science, technology, and
the environment.
Level 4
Makes affective and
descriptive connections
between data/research
with science, technology,
and the environment.
Q4. What type of biome does this interaction between wolves and hares occur? (You may have to research this on
the internet). Describe the climate and vegetation of this biome.
Q5. Wolves need to catch and eat several hares in order to survive because when the wolf eats the hare only 10%
of the hare’s energy is passed on to wolf. What has happened to the 90% of energy that the wolf does not get?
Q6. Describe in detail 2 types of adaptations hares could develop in order to avoid being eaten by wolves.
1 2 3 4
Q7. Besides predators, describe several other limiting factors that could prevent hare populations from increasing.
Are these factors biotic or abiotic?
1 2 3 4
TOTAL APPLICATION MARKS:
/16
Page 13 of 16
1 2 3 4
1 2 3 4
Blank Page for Double-Sided Printing
Page 14 of 16
Activity D – Unit Assessment
 Hand in for assessment: level
After completing all the learning checkboxes, you are now ready to complete your unit assessment. Answer the
following questions and hand in to your teacher. Some questions will be the same as the ones you have already done in
your notebook.
After your teacher reviews your answers you will receive a unit assessment feedback sheet. You will not get a numerical
mark for this assessment but a level from the rubric below and feedback on where you need to improve.
Level 1
Knowledge
Minimal knowledge of
facts, terms, concepts,
theories and relationships
was demonstrated.
Level 2
Some knowledge of facts,
terms, concepts, theories
and relationships was
demonstrated.
Level 3
Level 4
Adequate knowledge of
facts, terms, concepts,
theories and relationships
from the unit was
demonstrated
Thorough knowledge of
facts, terms, concepts,
theories and relationships
from the unit was
demonstrated
Interactions in Ecosystems
1) How do similar species that feed on the same prey coexist in an area together and avoid competition?
2) Describe an example not from your textbook of an adaptation an organism uses to avoid being eaten.
3) What is symbiosis? What are the 3 main types of symbiosis?
Page 15 of 16
4) Classify the following interactions as mutualism, commensalism, or parasitism:
a) Yucca moth caterpillar feeds on the yucca plant and pollinates the yucca plant
b) Lice feed harmlessly on the feathers of birds
c) Cowbird removes an egg from a robin’s nest and replaces it with one of its own
d) An orchid plant grows on the branch of a tree. The tree remains healthy
Carrying Capacity and Limiting Factors
5)
A squirrel population grows in a forest until they reach their carrying capacity. What are some abiotic and biotic
factors that limit the overpopulation of squirrels?
Congratulations! You have now completed Unit #3.
Page 16 of 16