See below!
Unit 3: Earth and Life - Interactions and Feedback
WebQuest PS 13
Causes, Effects, and Feedback
Intro:
In this assignment, you will explore specific examples of feedback loops that exist in nature such that a change in one system leads to changes in another.
Please complete this assignment using a DIFFERENT font color than the questions in purple that is easy to read and distinguish.
Please use the space you need to answer the question (spacing has been removed between questions).
Grading:
This “Research PS13” will be evaluated by the rubric below and weighted as 30 points.
4 – 90% (27/30)
3 – 80% (24/30)
2 – 70% (21/30)
1 - < 70% (less than 21 points)
PS13
HS-ESS2-2: Analyze geoscience data to make the claim that one change to Earth’s surface can create feedbacks that cause changes to other Earth’s systems
| 4 | 3 | 2 | 1 | |
| Excelling Excelling means the student has thoroughly demonstrated knowledge on standard assessed. | Meeting Meeting means the student has demonstrated competence on standard assessed. | Approaching Approaching means the student has partially demonstrated competence on standard assessed. | Beginning Beginning means the student has not yet demonstrated competence on standard assessed. | |
| Student develops a model showing a feedback loop for system I that is clear, correct, and follows 4 steps. See instructions for system I model. AND Student develops a model showing a feedback loop for system II that is clear, correct, and follows 4 steps. See instructions for system II model. AND Student develops a model showing a feedback loop for system III that is clear, correct, and follows 4 steps. See instructions for system III model. | Does not meet requirements for level 4. Student develops a model showing a feedback loop for system I that is clear, correct, and follows 4 steps. See instructions for system I model. AND Student develops a model showing a feedback loop for system II that is clear, correct, and follows 4 steps. See instructions for system II model. | Does not meet requirements for level 3.
Student develops a model showing a feedback loop for system I that is clear, correct, and follows 4 steps. See instructions for system I model. | Does not meet requirements for level 2. OR Understanding cannot be determined as answers are vague, incomplete, missing, or incomprehensible. |
Research: Feedback Systems
Preparation Step 1: EXPLORE - Examples of Feedback Systems
You have likely heard the term “feedback loop.” When a change is made in one system that leads to a change in another system, this is considered a “feedback loop.”
Nature is filled with feedback systems.
You find feedback systems within living organisms that control blood sugar levels, body temperature, etc.
You find feedback systems within ecology studies in which changes in climate, vegetation, etc. can lead to changes in other systems.
There are different types of feedback systems.
Let’s look at two specific kinds of feedback systems.
POSITIVE FEEDBACK SYSTEMS:
A positive feedback system is one which the system will try to ENHANCE/AMPLIFY/INCREASE the original change made.
A common example provided is the body’s system approach to increase contractions during labor.
Study the next two slides to see this.
The big idea?
The original change:
INCREASE pressure on cervix from baby’s head pushing
The system’s response:
INCREASE release of oxytocin which travels via blood stream to uterus and leads to INCREASED contractions which leads to INCREASED pressure on cervix from baby’s head pushing
https://www.quora.com/Human-Physiology-Why-do-we-consider-the-effect-of-oxytocin-as-a-positive-feedback (accessed 5/8/2017)
http://slideplayer.com/slide/4892408/ (accessed 5/8/2017)
NEGATIVE FEEDBACK SYSTEMS:
A negative feedback system is one in which the system will try to COUNTERACT the original change made and return the system to its original state.
A common example provided is the body’s system to control blood sugar.
Study the next two slides to see this.
The big idea?
The original change:
INCREASE blood sugar levels (maybe you just devoured a Snicker’s bar)
The system’s response:
DECREASE blood sugar levels back to their original or healthy level (the pancreas releases the hormone insulin to cause the body’s cells to absorb glucose and thus remove it from the blood)
http://slideplayer.com/slide/4892408/ (accessed 5/8/2017)
http://slideplayer.com/slide/4892408/ (accessed 5/8/2017)
A SUMMARY OF POSITIVE AND NEGATIVE FEEDBACK SYSTEMS:
The below image summarizes the distinctions between positive and negative feedback loops.
Preparation Step 2: REVIEW – Elements and Instructions for your Assignment
Feedback loops don’t just occur in the body!
In fact, Earth is filled with examples of feedback loops that exist between various systems.
In this assignment, you will:
(1) COLLECT information from the web about specific feedback systems in nature. PROVIDE URL(s) you referred to in the diagram construction and captions.
(2) CONSTRUCT a simple feedback loop diagram.
(3) PROVIDE short captions to accompany your feedback loop diagram at each stage of the loop.
(4) PROVIDE a 2-3 sentence summary of your model:
- EXPLAIN the overall feedback loop.
- EXPLAIN, if applicable, whether your model is a positive feedback system or negative feedback system and EXPLAIN how you determined this.
What might this look like?
Let’s walk through of the 5 steps from above so you can see an example!
Ready? Here we go!
(1) COLLECT information from the web about specific feedback systems in nature. PROVIDE URL(s) you referred to in the diagram construction and captions.
I referenced the website below that explained how soil nutrients can be increased and how soil nutrients can be decreased.
https://www.extension.umn.edu/garden/fruit-vegetable/nutrient-cycling-and-fertility/ (accessed 5/8/2017)
Key Points from this website that I used in my model below:
Soil nutrients increases from fertilizer, weathering of rocks, decomposition of organic matter (plant/animal remains and microrganisms), animal waste, deposition of nutrients due to erosion processes bringing nutrient-rich sediments to the soil
Soil nutrients decrease from runoff, erosion carrying nutrient-rich sediments away from the soil, crop removal (when crops absorb nutrients from the soil – stripping the soil of nutrients over time)
My model specifically referred to the process of decomposition via termites/fungi/bacteria that added to soil nutrients
(2) CONSTRUCT a simple feedback loop diagram.
(3) PROVIDE short captions to accompany your feedback loop diagram at each stage of the loop.
The image I found is from the website https://www.slideshare.net/total/lesson-2-rainforest-ecosystems (accessed 5/8/2017)
Notice, the captions at each stage of the cycle that “walk us through” the cycle.
REMEMBER – you will construct your own model!
You will not insert a Google image directly like I did here!
However, I am fine if you base your model on an example from Google images provided you cite your source AND explain the image fully in your own words and captions.
(4) PROVIDE a 2-3 sentence summary of your model:
- EXPLAIN the overall feedback loop.
- EXPLAIN, if applicable, whether your model is a positive feedback system or negative feedback system and EXPLAIN how you determined this.
In my model above, the feedback loop that exists between vegetation and soil nutrients is shown. The process begins with an area that includes dense vegetation (lots of plant matter). As various trees, bushes, and flowering plants drop plant matter (leaves, twigs, flowers) to the ground, this organic matter begins to collect on the soil surface. Next, this organic matter gradually gets broken down by termites, fungi, and bacteria. Next, the break-down of organic matter leads to the release of nutrients into the soil. Next, the soil becomes increasingly nutrient-rich and thus fertile over time. Finally, this spike in nutrients in the soil increases vegetation density, completing the feedback loop.
Overall, the process appears to be a positive feedback loop as the starting change (increased plant vegetation) is amplified/enhanced in this feedback loop. In other words, greater vegetation density leads to more plant matter deposition and decomposition which in turn leads to more nutrients released which in turn causes an increase in plant vegetation density.
NOTE: Students seeking a “2” will complete the above steps for a total of (1) system – this means you must do the option related to greenhouse gases etc. found in feedback system I below.
NOTE: Students seeking a “3” will complete the above steps for a total of (2) different systems – this means you must do the option related to greenhouse etc. found in feedback system I AND choose 1 option from feedback system II.
NOTE: Students seeking a “4” will complete the above steps for a total of (3) different systems – this means you must do the option related to greenhouse gases etc. found in feedback system I AND choose 1 option from feedback system II AND choose 1 option from feedback system II.
Feedback System I – REQUIRED for all students
Follow steps below to describe the feedback loop that exists between the following system components below:
Glacial Ice
Greenhouse Gases
Global Temperatures
(1) COLLECT information from the web about specific feedback systems in nature. PROVIDE URL(s) you referred to in the diagram construction and captions.
(2) CONSTRUCT a simple feedback loop diagram.
(3) PROVIDE short captions to accompany your feedback loop diagram at each stage of the loop.
(4) PROVIDE a 2-3 sentence summary of your model:
- EXPLAIN the overall feedback loop.
- EXPLAIN, if applicable, whether your model is a positive feedback system or negative feedback system and EXPLAIN how you determined this.
INSERT your model based on steps 1-4 in the space below.
You can complete this model by hand OR using Microsoft paint.
You can refer to Google Images but should create your own model (again, just cite your source that you used to construct your model).
Feedback System II
Follow steps below to describe the feedback loop that exists between ONE of the following feedback systems below:
Option 1:
Vegetation
Water runoff and erosion
Option 2:
River dams
Sediment transport
Coastal Erosion
Option 3:
Wetland area
humidity
(1) COLLECT information from the web about specific feedback systems in nature. PROVIDE URL(s) you referred to in the diagram construction and captions.
(2) CONSTRUCT a simple feedback loop diagram.
(3) PROVIDE short captions to accompany your feedback loop diagram at each stage of the loop.
(4) PROVIDE a 2-3 sentence summary of your model:
- EXPLAIN the overall feedback loop.
- EXPLAIN, if applicable, whether your model is a positive feedback system or negative feedback system and EXPLAIN how you determined this.
INSERT your model based on steps 1-4 in the space below.
You can complete this model by hand OR using Microsoft paint.
You can refer to Google Images but should create your own model (again, just cite your source that you used to construct your model).
Feedback System III
Follow steps below to describe the feedback loop that exists between ONE of the following feedback systems below (notice that this final feedback system III allows you to choose your own feedback system for option 4):
Option 1:
Vegetation
Water runoff and erosion
Option 2:
River dams
Sediment transport
Coastal Erosion
Option 3:
Wetland area
humidity
OR
Option 4 – YOUR CHOICE – HEAD TO GOOGLE IMAGES AND SELECT A FEEDBACK SYSTEM THAT INTERESTS YOU
(1) COLLECT information from the web about specific feedback systems in nature. PROVIDE URL(s) you referred to in the diagram construction and captions.
(2) CONSTRUCT a simple feedback loop diagram.
(3) PROVIDE short captions to accompany your feedback loop diagram at each stage of the loop.
(4) PROVIDE a 2-3 sentence summary of your model:
- EXPLAIN the overall feedback loop.
- EXPLAIN, if applicable, whether your model is a positive feedback system or negative feedback system and EXPLAIN how you determined this.
INSERT your model based on steps 1-4 in the space below.
You can complete this model by hand OR using Microsoft paint.
You can refer to Google Images but should create your own model (again, just cite your source that you used to construct your model).
