In this lab students will have a chance to explore the effects of limiting factors on a pair of ducks. Students will then examine why the limiting factors influences the carrying capacity of a population. Students will collect data and analyze it before drawing a conclusion about limiting factors and carrying capacity.
Learning Objectives: What should students know and be able to do as a result of this lesson?
Students will be able to:
Visualize the effects limiting factors influences population size.
Describe why limiting factors influence population size.
Prior Knowledge: What prior knowledge should students have for this lesson?
Students should have prior knowledge of what a population is. Students should also have knowledge of how to graph data.
Guiding Questions: What are the guiding questions for this lesson?
Teacher probing questions
How can a factor be determined as a limiting factor?
Why would a population reach carrying capacity?
What are some factors that would cause a population to reach carrying capacity?
What might happen if a population was to surpass its carrying capacity?
What are examples of a limiting factor?
Could an event, such as pesticide runoff, affect a population size
If the factor has controlled the size of the population
Carrying capacity is reached if the population does not have enough resources to sustain the size of the population.
Water, food, shelter, predators
A population can not sustain itself if it exceeds its carrying capacity. Therefore the population size would decrease until the environment is able to support it again.
Anything that limits the size of a population.
Yes, the pesticides could kill a certain amount of the population or kill the food source therefore changing the population size.
Teaching Phase: How will the teacher present the concept or skill to students?
The teacher will introduce the topic of limiting factors and carrying capacity by showing a Youtube Video to engage students. Once the students have viewed the video the teacher will have the students record what they believe carrying capacity and limiting factors are on a sheet of notebook paper to reflect on at the completion of the activity. Have students turn to a shoulder partner and share what their definition of carrying capacity and limiting factors are.
The teacher will then distribute the lab work sheet for the students to deepen their knowledge of the topic. The teacher will also distribute the bag with the components needed for the lab at this time.
The teacher will demonstrate how to complete the lab.
Read the directions
Ask if there are any questions.
Read scenario one to the class.
Place 50 beans on the grid paper
Explain that the beans represent fish and the grid represents the lake.
Take thebluesquare of paper and drop it on the grid
Explain that the blue square represents a duck
How many fish the duck caught
Record the number of fish caught under Day one in the blue duck row.
Repeat step 4 and 5 for the pink duck.
Add the total number of fish for the blue duck and pink duck
Record this number under day one in the daily total row.
Repeat steps 4-7 for day 2 and day 3.
Take the daily total for day one and two and add them together
Record this number in the two day total under the day two column.
If the ducks did not catch a total of 4 fish in the two day span the ducks die do not continue
If the ducks caught a total of 4 fish in the two day span repeat steps 4-9 for day 3 and day 4.
Continue this process until the ducks die or until you reach day 10
At this point the teacher may ask the students some of the probing questions (found under guiding questions).
After the first scenario has been run as a demonstration have the students work in groups of three or less to complete the remaining scenarios.
At the conclusion of the activity have the students revisit their definition of carrying capacity and limiting factors at this point they may change or modify the definition. Remind students to not change their original definition. Have the students share with the class what their definition is and how it compares to their original definition.
Guided Practice: What activities or exercises will the students complete with teacher guidance?
Students will predict the outcomes of the duck population as different events occur. Students will also predict what is ultimately controlling the population's size.
Independent Practice: What activities or exercises will students complete to reinforce the concepts and skills developed in the lesson?
Students will observe the changes of a duck population with the limiting factor changing. Students will record their data and then communicate their findings though the use of graphs.
Closure: How will the teacher assist students in organizing the knowledge gained in the lesson?
Students will have a list of guiding questions in their lab worksheet to help them explain their observations of population growth, limiting factors, and carrying capacity. Students will also reflect on their definitions of limiting factors and carrying capcity.
To have data on the complete understanding of the main standards, the students will complete a lab write up and demonstrate their knowledge of how population size is effected by different limiting factors through analyzing student collected data. Students will demonstrate their mastery of the standards by accurately defining limiting factors and carrying capacity. Mastery will also be demonstrated by the completing of question 14 on the lab hand out.
Teachers will ask the student (in groups or individually) questions about their findings with regards to limiting factors. Another way to monitor student success in terms of the standards is to examine the student generated data towards the completion of the activity.
Feedback to Students
Students will receive feedback throughout the activity within their groups. Having immediate feedback will allow the students to ensure they are on track for meeting the learning objectives.
Accommodations & Recommendations
One modification is completing the activity on under a document camera or with the student. Another modification is to allow extra time on the assignment. The last modification would be reducing the reading on the handout.
Have students research a local population of a species. Have them identify the limiting factors. Once they know the limiting factors have them predict what would happen to the population if the limiting factor increases, decreases, or changes.
Identify relationships among organisms, including helping each other (mutualism); obtaining food (predation); benefiting at the expense of the other (parasitism); and competing with each other for food, space, or shelter (competition).