Artifact #1: Mathematics
In second semester of my junior year, I took Math 13 (statistics) at Laney College. The extra credit project was to conduct an experiment and analyze it with the methods we had learned over the course of the class.
Statistics Project Write-Up
1. Statement of the problem: Do students with high and low hours of sleep differ with respect to GPA? It is hard to tell, because there are two ways to look at this. If someone gets a lot of sleep, they are usually healthier and perform better, in and out of school. But what if someone doesn’t get a lot of sleep because they’re doing work for school? Many people stay up late every night finishing and perfecting all of their projects to earn those few extra points. So does amount of sleep really have an affect on your GPA? Extracurriculars could also have an affect on either variable, so participants were asked to share those as well.
2. Statistical context: Unit – one ACLC high school student
Population – all ACLC high school students; Population size: N=150
Sample – all ACLC high schoolers in the modern world history classes; n= 52
Variables – amount of sleep and GPA; dichotomous & numerical. Both are measured to the tenths decimal place.
3. Sampling method: Knowing it would be very difficult to pick out as many high schoolers possible throughout the day, I had my modern world history teacher let me survey all the students in his three classes he had that day. The survey I created was on paper, with columns for GPA, hours of sleep, and extracurriculars. Students could choose whether they were comfortable filling it out or not, but it is a completely anonymous survey. It seems not everyone was keen on participating, for only 52 slots were filled. Compared to the population size, it is a large amount and will be enough to draw conclusions.
4. The raw data: not available
5. The data organized and described:
1. Statement of the problem: Do students with high and low hours of sleep differ with respect to GPA? It is hard to tell, because there are two ways to look at this. If someone gets a lot of sleep, they are usually healthier and perform better, in and out of school. But what if someone doesn’t get a lot of sleep because they’re doing work for school? Many people stay up late every night finishing and perfecting all of their projects to earn those few extra points. So does amount of sleep really have an affect on your GPA? Extracurriculars could also have an affect on either variable, so participants were asked to share those as well.
2. Statistical context: Unit – one ACLC high school student
Population – all ACLC high school students; Population size: N=150
Sample – all ACLC high schoolers in the modern world history classes; n= 52
Variables – amount of sleep and GPA; dichotomous & numerical. Both are measured to the tenths decimal place.
3. Sampling method: Knowing it would be very difficult to pick out as many high schoolers possible throughout the day, I had my modern world history teacher let me survey all the students in his three classes he had that day. The survey I created was on paper, with columns for GPA, hours of sleep, and extracurriculars. Students could choose whether they were comfortable filling it out or not, but it is a completely anonymous survey. It seems not everyone was keen on participating, for only 52 slots were filled. Compared to the population size, it is a large amount and will be enough to draw conclusions.
4. The raw data: not available
5. The data organized and described:
Low: > 8 hours; High: ≤ 8 hours
GPA: mean= 3.6, median= 3.8, mode= 4, range= 2-4.3
Number of hours of sleep: mean= 6.9, median= 7, mode= 7, range= 3-9
Histogram for GPA
GPA: mean= 3.6, median= 3.8, mode= 4, range= 2-4.3
Number of hours of sleep: mean= 6.9, median= 7, mode= 7, range= 3-9
Histogram for GPA
Histogram for Number of Hours of Sleep
SD line: green; Regression line: red; Equation of regression line: y = 0.85x + 3.785
Confidence Interval
Variable #1: success is high GPA and low amount of sleep
We are 95% confident that the interval from 27.0% to 53.7% contains the percentage of all high school ACLC students with high GPAs and low amounts of sleep.
Variable #2: success is medium GPA and low amount of sleep
We are 95% confident that the interval from 10.1% to 32.3% contains the percentage of all high school ACLC students with medium GPAs and low amounts of sleep.
Chi-Square Test for Independence
SD= 0.6%, α= 5%, x2= 2.18
Decision rule: reject H0 if x2>5.99
Decision: do not reject H0 , results are not statistically significant.
P-value: 33.6%
Extracurriculars showed to not have a major effect on the variables tested. 88% of the sample has at least one extracurricular, and there is no obvious change with the remaining six who did not put any down. Because of this and knowing it would be difficult to mathematically prove anything with the information, I decided to drop this variable in my calculations.
6. Inferences about the population: Even though the sample shows an association with GPA and average hours of sleep through numbers and graphs, this can not be applied to the population as well. The chi-square test proved the null hypothesis of a non-association to be true. The variables being tested didn’t fit the tools used correctly. There is no definition of “success” in the problem, I’m just trying to find associations. Using the information gathered, I chose two variables to test to prove their association differences and confidence intervals.
7. A critique of your work: 1) Yes my question posed was answered, and GPA and average number of hours of sleep per night are not associated. 2) If someone were to criticize my work, they would probably object to my sampling method. Only surveying three separate classes didn’t seem to be enough to compute a strong conclusion for a test like this. Compared to the initial population, 52 is a large portion. However, in general, 52 is a small number and difficult to use to come up with an inference no matter the population size. Next time, this project would do much better if I had gotten double the sample size I did this time around. My original question, comparing hours of sleep and number of classes, would also be better to test because it makes more sense overall and seems to be more beneficial in the long run. 3) I was definitely most surprised by the difficulty of finding appropriate graphs and data organizers for my specific data collection and initial analysis. A lot of data analyzers we have used in class this last semester didn’t seem to support my data and hypothesis. I was also surprised by the results of the test. After seeing what the sample came up with, I was sure that those who had higher GPAs would get less sleep each night, but the chi-squared test proved that wrong for the population. 4) During this project, I learned that gathering and composing data and a whole test from scratch has a lot more depth to it than I previously thought. I have to admit, when I first read the assignment, I didn’t think too much of it and thought it would be fairly easy. But I spent much more time and effort than expected having to go through all those spreadsheets and picking appropriate graphs. Something as simple as GPA vs. sleep can have a lot more to it than initially thought of, and it makes me wonder what more we can do with this math and all those simple real-life problems that we might have yet to look more closely at.
Confidence Interval
Variable #1: success is high GPA and low amount of sleep
We are 95% confident that the interval from 27.0% to 53.7% contains the percentage of all high school ACLC students with high GPAs and low amounts of sleep.
Variable #2: success is medium GPA and low amount of sleep
We are 95% confident that the interval from 10.1% to 32.3% contains the percentage of all high school ACLC students with medium GPAs and low amounts of sleep.
Chi-Square Test for Independence
SD= 0.6%, α= 5%, x2= 2.18
Decision rule: reject H0 if x2>5.99
Decision: do not reject H0 , results are not statistically significant.
P-value: 33.6%
Extracurriculars showed to not have a major effect on the variables tested. 88% of the sample has at least one extracurricular, and there is no obvious change with the remaining six who did not put any down. Because of this and knowing it would be difficult to mathematically prove anything with the information, I decided to drop this variable in my calculations.
6. Inferences about the population: Even though the sample shows an association with GPA and average hours of sleep through numbers and graphs, this can not be applied to the population as well. The chi-square test proved the null hypothesis of a non-association to be true. The variables being tested didn’t fit the tools used correctly. There is no definition of “success” in the problem, I’m just trying to find associations. Using the information gathered, I chose two variables to test to prove their association differences and confidence intervals.
7. A critique of your work: 1) Yes my question posed was answered, and GPA and average number of hours of sleep per night are not associated. 2) If someone were to criticize my work, they would probably object to my sampling method. Only surveying three separate classes didn’t seem to be enough to compute a strong conclusion for a test like this. Compared to the initial population, 52 is a large portion. However, in general, 52 is a small number and difficult to use to come up with an inference no matter the population size. Next time, this project would do much better if I had gotten double the sample size I did this time around. My original question, comparing hours of sleep and number of classes, would also be better to test because it makes more sense overall and seems to be more beneficial in the long run. 3) I was definitely most surprised by the difficulty of finding appropriate graphs and data organizers for my specific data collection and initial analysis. A lot of data analyzers we have used in class this last semester didn’t seem to support my data and hypothesis. I was also surprised by the results of the test. After seeing what the sample came up with, I was sure that those who had higher GPAs would get less sleep each night, but the chi-squared test proved that wrong for the population. 4) During this project, I learned that gathering and composing data and a whole test from scratch has a lot more depth to it than I previously thought. I have to admit, when I first read the assignment, I didn’t think too much of it and thought it would be fairly easy. But I spent much more time and effort than expected having to go through all those spreadsheets and picking appropriate graphs. Something as simple as GPA vs. sleep can have a lot more to it than initially thought of, and it makes me wonder what more we can do with this math and all those simple real-life problems that we might have yet to look more closely at.
Artifact #2: English
In the first semester of my senior year, the first unit focused on was transcendentalism. At the end of it, we compiled all the works we had read to reach a conclusion about the topic and had to write an essay on it.
Clever Title About Nature
With the Transcendentalist movement in mid 1800s came many new, flourishing ideas that inspired those involved to become more in touch with subjects like individualism and harmony between man and nature. It is believed by the people in said movement that nature has a pure connection to the soul since everything’s roots lead back to nature. However, the human race has seemed to have lost familiarity with nature due to population growth and the need to expand and industrialize. Our instinct to survive and expand has stunted people’s ability to appreciate the world around us more and more every day, especially those of younger generations who have grown up in a more technology-reliant society. We have become blinded by the need to gather the resources nature has provided for us for survival without even taking the consequences into consideration. Because of this, our planet is becoming diminished and many essential things that nature provides have become alarmingly scarce. This issue has lead to today’s closed-mindedness towards our imperative surroundings. Man believes that nature’s first priority is to “serve” human kind’s necessities, however, they underestimate its true purpose and beauty by taking resources for granted.
When you look outside, it might not seem too obvious that our future is in peril. We might still have blue skies and grassy parks, but this is not the case everywhere. Destructive practices such as deforestation has caused so much more long-term harm than needed. According to scientific writer Alina Bradford, about half the world’s tropical forests have been cleared to make land for urbanization. Burning trees and clear cutting vast landscapes is extremely damaging since natural forests are limited and their destruction can be permanent. Another catastrophe that has a drastic effect on the world around us is air pollution. Smog made of carbon dioxide is scattered throughout the atmosphere all over the earth and does nothing but harm to all living beings. This greenhouse gas emitted by man-made objects such as cars and power plants is the primary contributor to global warming. Human activities, such as the burning of fossil fuels, pumps more chemical waste into the air. Toxic fumes can defect one’s body and is incredibly harmful to the lives of animals and plants. Even though we are starting to work on reducing waste and fixing the environment, no amount of effort will be enough to repair what we have broken.
Issues like these are probably good reasons behind why Lord Byron bad-mouthed humans when they invaded untouched land in his poem Childe Harold’s Pilgrimage. In his work, he conveys a very worshipful tone as he explains that he “love[s] not Man the less, but Nature more” (ln 5). Evidently, he begins to discourage man’s habitation and blatantly states that “man marks the earth with ruin” (ln 12), showing his distaste towards that decision. Byron is not the only one who agrees that man has left a long-lasting mark on the earth. Henry David Thoreau, a well known Transcendentalist author, decided to live alone in the woods for over two years to strengthen the bond between himself and the wilderness. He too had a strong appreciation for the simple and natural state of things, and explains that “the surface of the earth is soft and impressible by the feet of men” (pg 203) in his renowned novel, Walden. Thoreau explains the caution we need to take as humans when we disturb the natural order of things. This line makes me think of the earth as a ball of clay, and the person handling it is the human race. We have the ability mould and shape our world however we want, but if we fiddle with it too much, it will eventually crumble in our hands.
Humans tend to rely entirely on nature to survive, but that might not still be the case if you switch the roles around. Every aspect of nature is very self-sufficient and every organism has given instincts ingrained into their genes to survive. For example, when forest fires destroy massive amounts of wildlife, nature uses this destruction to its advantage. The demolition of old vegetation creates space for new life and returns nutrients to the soil. This natural way of regeneration is necessary for ecosystems to evolve. Nature is perfectly sustainably capable without any assistance from man, however man needs nature to survive. This is clearly shown in the 2007 film Into the Wild, where a young man named Chris ventures out through the wilderness alone. In order to survive, Chris relies on the wildlife around him to feed him and the vegetation to shelter him. If it was not for the availability of the surrounding living organisms, he would have been dead a lot sooner. Author Ralph Waldo Emerson supports nature’s independence in one of his essays called Self-Reliance. There is no need for nature to associate itself with non-relative things because it “suffers nothing to remain in her kingdoms which cannot help itself” (pg 30). There are no consequences to nature if it keeps to itself and continues through the countless cycles that make up all ecosystems. However, this is not so true for humans. We suffer dearly if we keep to ourselves and stop relying on nature to help our survival. Emerson also seems to have a lot to say about the relationship between man and nature and expresses his opinions in his essay appropriately titled Nature. He is an avid supporter of everything natural and possesses nothing but love for the stars in the sky and the dirt under his feet. He claims “in good health, the air is a cordial of incredible virtue” (pg 183). More simply put, our atmosphere not only contains key elements needed to live, but it is the stimulator for moral goodness. This is not anything you can just obtain and is only accessible through reaching a certain level of respect towards our earth.
To create a balanced relationship between the two, humans must understand our wrongs and stop overlooking beauty in nature. There is so much in the world to discover and so much more to appreciate, yet humans are too caught up in using nature for economic benefits instead of realizing what else there is to gain from it. Emerson continues to touch on the subject of appreciation towards the earth in Nature by saying “nature never became a toy to a wise spirit” (pg 182). In other words, those who are wise respect nature and do not take it for advantage. Treating it as if it had little value like a toy would be immature, especially since we would be directly affected by the outcome. However one does not need to disturb the natural order to find happiness. In Childe Harold’s Pilgrimage, Byron claims that he finds “pleasure in the pathless woods” (ln 1). People are still able to find peace in the solitude and purity of an unviolated piece of nature. The simplicity of these sights seem to encapture Byron and allow him to treasure these moments. Not only do slightly biased Transcendentalist authors and poets acknowledge the benefits of keeping nature pure, but scientific experiments to prove that nature aids health have been conducted as well. Environmental scientist Greg Bratman was able to prove that spending time in nature helps humans develop psychologically. Subjects who were asked to take 90 minute walks in nature showed to have lessened blood flow to the subgenual prefrontal cortex. This area of the brain is where rumination occurs, which is the pattern of thought focused on the negatives of oneself. Not only can it help physically, but being in the outdoors can improve the mental health and train of thought for anybody.
How is it still that humans are not able to truly grasp the importance of keeping our planet sustained? Why is it that humans expect so much of nature, but never give anything in return? We already know that humans are entirely dependent on natural resources, yet we continue to poorly plan and misuse them, slowly leading to annihilation and eventual permanent loss. We fail to see the earth’s own self-reliance and disregard how important each element in our world actually is to us. Instead, we need to change the way we think and stop the exploitation of limited resources. By educating anyone and everyone and attempting to make a difference, we can secure a positive outcome and provide a sustainable future for generations to come.
Works Cited
“Air Pollution.” National Geographic, National Geographic Society. n.d. Web. 19 October 2015. <http://environment.nationalgeographic.com/environment/global-warming/pollution-overview/>
Bradford, Alina. “Deforestation: Facts, Causes, & Affects.” livescience.com, Purch. 04 March 2015. Web. 13 October 2015. <http://www.livescience.com/27692-deforestation.html>
Emerson, Ralph Waldo. Nature. Boston: James Munroe and Company, 1836. Print.
Emerson, Ralph Waldo. Self-Reliance. New York: Dover Publications, Inc., 1993. Print.
Goodstein, Eli. “Stanford Study Says Spending Time in Nature Benefits Mental Health.” USA Today, n.p. 9 July 2015. Web. 13 October 2015. <http://college.usatoday.com/2015/07/09/study-nature-good-for-mental-health/ >
Gordon, George. Childe Harold’s Pilgrimage. Kinsham: n.p., 1812-1818. Print.
Into the Wild. Dir. Sean Penn. Perf. Emile Hirsch, Vince Vaughn, and Catherine Keener. Paramount Vantage, 2007. Film
Thoreau, Henry David. Walden, or Life in the Woods. Concord, MA: 1954. Print.
With the Transcendentalist movement in mid 1800s came many new, flourishing ideas that inspired those involved to become more in touch with subjects like individualism and harmony between man and nature. It is believed by the people in said movement that nature has a pure connection to the soul since everything’s roots lead back to nature. However, the human race has seemed to have lost familiarity with nature due to population growth and the need to expand and industrialize. Our instinct to survive and expand has stunted people’s ability to appreciate the world around us more and more every day, especially those of younger generations who have grown up in a more technology-reliant society. We have become blinded by the need to gather the resources nature has provided for us for survival without even taking the consequences into consideration. Because of this, our planet is becoming diminished and many essential things that nature provides have become alarmingly scarce. This issue has lead to today’s closed-mindedness towards our imperative surroundings. Man believes that nature’s first priority is to “serve” human kind’s necessities, however, they underestimate its true purpose and beauty by taking resources for granted.
When you look outside, it might not seem too obvious that our future is in peril. We might still have blue skies and grassy parks, but this is not the case everywhere. Destructive practices such as deforestation has caused so much more long-term harm than needed. According to scientific writer Alina Bradford, about half the world’s tropical forests have been cleared to make land for urbanization. Burning trees and clear cutting vast landscapes is extremely damaging since natural forests are limited and their destruction can be permanent. Another catastrophe that has a drastic effect on the world around us is air pollution. Smog made of carbon dioxide is scattered throughout the atmosphere all over the earth and does nothing but harm to all living beings. This greenhouse gas emitted by man-made objects such as cars and power plants is the primary contributor to global warming. Human activities, such as the burning of fossil fuels, pumps more chemical waste into the air. Toxic fumes can defect one’s body and is incredibly harmful to the lives of animals and plants. Even though we are starting to work on reducing waste and fixing the environment, no amount of effort will be enough to repair what we have broken.
Issues like these are probably good reasons behind why Lord Byron bad-mouthed humans when they invaded untouched land in his poem Childe Harold’s Pilgrimage. In his work, he conveys a very worshipful tone as he explains that he “love[s] not Man the less, but Nature more” (ln 5). Evidently, he begins to discourage man’s habitation and blatantly states that “man marks the earth with ruin” (ln 12), showing his distaste towards that decision. Byron is not the only one who agrees that man has left a long-lasting mark on the earth. Henry David Thoreau, a well known Transcendentalist author, decided to live alone in the woods for over two years to strengthen the bond between himself and the wilderness. He too had a strong appreciation for the simple and natural state of things, and explains that “the surface of the earth is soft and impressible by the feet of men” (pg 203) in his renowned novel, Walden. Thoreau explains the caution we need to take as humans when we disturb the natural order of things. This line makes me think of the earth as a ball of clay, and the person handling it is the human race. We have the ability mould and shape our world however we want, but if we fiddle with it too much, it will eventually crumble in our hands.
Humans tend to rely entirely on nature to survive, but that might not still be the case if you switch the roles around. Every aspect of nature is very self-sufficient and every organism has given instincts ingrained into their genes to survive. For example, when forest fires destroy massive amounts of wildlife, nature uses this destruction to its advantage. The demolition of old vegetation creates space for new life and returns nutrients to the soil. This natural way of regeneration is necessary for ecosystems to evolve. Nature is perfectly sustainably capable without any assistance from man, however man needs nature to survive. This is clearly shown in the 2007 film Into the Wild, where a young man named Chris ventures out through the wilderness alone. In order to survive, Chris relies on the wildlife around him to feed him and the vegetation to shelter him. If it was not for the availability of the surrounding living organisms, he would have been dead a lot sooner. Author Ralph Waldo Emerson supports nature’s independence in one of his essays called Self-Reliance. There is no need for nature to associate itself with non-relative things because it “suffers nothing to remain in her kingdoms which cannot help itself” (pg 30). There are no consequences to nature if it keeps to itself and continues through the countless cycles that make up all ecosystems. However, this is not so true for humans. We suffer dearly if we keep to ourselves and stop relying on nature to help our survival. Emerson also seems to have a lot to say about the relationship between man and nature and expresses his opinions in his essay appropriately titled Nature. He is an avid supporter of everything natural and possesses nothing but love for the stars in the sky and the dirt under his feet. He claims “in good health, the air is a cordial of incredible virtue” (pg 183). More simply put, our atmosphere not only contains key elements needed to live, but it is the stimulator for moral goodness. This is not anything you can just obtain and is only accessible through reaching a certain level of respect towards our earth.
To create a balanced relationship between the two, humans must understand our wrongs and stop overlooking beauty in nature. There is so much in the world to discover and so much more to appreciate, yet humans are too caught up in using nature for economic benefits instead of realizing what else there is to gain from it. Emerson continues to touch on the subject of appreciation towards the earth in Nature by saying “nature never became a toy to a wise spirit” (pg 182). In other words, those who are wise respect nature and do not take it for advantage. Treating it as if it had little value like a toy would be immature, especially since we would be directly affected by the outcome. However one does not need to disturb the natural order to find happiness. In Childe Harold’s Pilgrimage, Byron claims that he finds “pleasure in the pathless woods” (ln 1). People are still able to find peace in the solitude and purity of an unviolated piece of nature. The simplicity of these sights seem to encapture Byron and allow him to treasure these moments. Not only do slightly biased Transcendentalist authors and poets acknowledge the benefits of keeping nature pure, but scientific experiments to prove that nature aids health have been conducted as well. Environmental scientist Greg Bratman was able to prove that spending time in nature helps humans develop psychologically. Subjects who were asked to take 90 minute walks in nature showed to have lessened blood flow to the subgenual prefrontal cortex. This area of the brain is where rumination occurs, which is the pattern of thought focused on the negatives of oneself. Not only can it help physically, but being in the outdoors can improve the mental health and train of thought for anybody.
How is it still that humans are not able to truly grasp the importance of keeping our planet sustained? Why is it that humans expect so much of nature, but never give anything in return? We already know that humans are entirely dependent on natural resources, yet we continue to poorly plan and misuse them, slowly leading to annihilation and eventual permanent loss. We fail to see the earth’s own self-reliance and disregard how important each element in our world actually is to us. Instead, we need to change the way we think and stop the exploitation of limited resources. By educating anyone and everyone and attempting to make a difference, we can secure a positive outcome and provide a sustainable future for generations to come.
Works Cited
“Air Pollution.” National Geographic, National Geographic Society. n.d. Web. 19 October 2015. <http://environment.nationalgeographic.com/environment/global-warming/pollution-overview/>
Bradford, Alina. “Deforestation: Facts, Causes, & Affects.” livescience.com, Purch. 04 March 2015. Web. 13 October 2015. <http://www.livescience.com/27692-deforestation.html>
Emerson, Ralph Waldo. Nature. Boston: James Munroe and Company, 1836. Print.
Emerson, Ralph Waldo. Self-Reliance. New York: Dover Publications, Inc., 1993. Print.
Goodstein, Eli. “Stanford Study Says Spending Time in Nature Benefits Mental Health.” USA Today, n.p. 9 July 2015. Web. 13 October 2015. <http://college.usatoday.com/2015/07/09/study-nature-good-for-mental-health/ >
Gordon, George. Childe Harold’s Pilgrimage. Kinsham: n.p., 1812-1818. Print.
Into the Wild. Dir. Sean Penn. Perf. Emile Hirsch, Vince Vaughn, and Catherine Keener. Paramount Vantage, 2007. Film
Thoreau, Henry David. Walden, or Life in the Woods. Concord, MA: 1954. Print.
Artifact #3: Science
In junior year, the whole biology class was tied up in our "duckweed investigation" as we spent weeks observing and counting these tiny plants floating in water. It was definitely a project that defined that class for me, so it felt wrong to not include my final report on my website.
Duckweed Formal Investigation Report
Abstract
When discovering new terms like carrying capacity, population growth rate, and ecosystem, it’s hard to truly understand and experience their meanings without being able to see it for yourself. That’s why this experiment was conducted to have a physical example to show what these terms come to in reality. The small but powerful plant duckweed was used in this investigation to help create a solid understanding. The duckweed is an aquatic and asexual plant, and can reproduce at an exponential rate. Because of its fast growth rate and ability to suck up all the dissolved carbon dioxide in a body of water, it is often seen as an invasive species since it prevents native plants from obtaining said carbon dioxide. This experiment was used to learn about the population of organisms through duckweed, how this population grows, and the differences in results shown when certain factors and starting numbers affect some population. Group 8 went into this investigation with the hypothesis that the population of duckweed would increase exponentially as time goes on. Due to its reproduction method, it would grow in a curve because the population would expand at a faster rate each week. The hypothesis was proven to be correct, and is expanded on more in the data and data analysis. However, this group was an outlier and the results found for all the other groups were a steady rise in population, then the decrease as it reached carrying capacity.
Experimental Design
In order to conduct this investigation, each group was given a different number of duckweed to start with and placed them in a plastic cup filled with spring water. Two of the nine groups started with 10 plants, another two started with 15, and so on for 20 and 25. The ninth group started out with 35 duckweed plants. The cups were then put under a light and carefully observed for the next eight weeks. Each week, the population number was recorded, and after time was up, each group came together with their data and the varying numbers were graphed. These small duckweed ecosystems were affected by the light they were given since the light was not on for all eight weeks. The results could have been very different if a light was beaming on the duckweed for a longer period of time, or if the plants were given almost no unnatural light at all.
Data
All of the results from this observation of duckweed population growth varied between groups. Even though the volume of the duckweed habitat seemed as if it would be a limiting factor for the population growth, it didn’t seem to affect any cup the same. Group 1 and 2 both started with 10 duckweed plants, but group 1 ended with 94 and group 2 ended with 58. Another drastic difference was between groups 5 and 6, who both started with 20 plants. Somehow, the numbers of duckweed plants for these two groups after eight weeks was 64 and 160. Group 4 ended up double the amount of their corresponding group, with 89 compared to group 3’s 46. The biggest outlier was with group 8, with a whopping 268 duckweed plants after eight weeks. Somehow their 25 turned into a massive amount, while group 7 finished with only 52. The last group, group 9, stood by themselves, and increased their number from 35 to 69. All of this can be seen in the data table and the graphs below.
Duckweed Class Data
Abstract
When discovering new terms like carrying capacity, population growth rate, and ecosystem, it’s hard to truly understand and experience their meanings without being able to see it for yourself. That’s why this experiment was conducted to have a physical example to show what these terms come to in reality. The small but powerful plant duckweed was used in this investigation to help create a solid understanding. The duckweed is an aquatic and asexual plant, and can reproduce at an exponential rate. Because of its fast growth rate and ability to suck up all the dissolved carbon dioxide in a body of water, it is often seen as an invasive species since it prevents native plants from obtaining said carbon dioxide. This experiment was used to learn about the population of organisms through duckweed, how this population grows, and the differences in results shown when certain factors and starting numbers affect some population. Group 8 went into this investigation with the hypothesis that the population of duckweed would increase exponentially as time goes on. Due to its reproduction method, it would grow in a curve because the population would expand at a faster rate each week. The hypothesis was proven to be correct, and is expanded on more in the data and data analysis. However, this group was an outlier and the results found for all the other groups were a steady rise in population, then the decrease as it reached carrying capacity.
Experimental Design
In order to conduct this investigation, each group was given a different number of duckweed to start with and placed them in a plastic cup filled with spring water. Two of the nine groups started with 10 plants, another two started with 15, and so on for 20 and 25. The ninth group started out with 35 duckweed plants. The cups were then put under a light and carefully observed for the next eight weeks. Each week, the population number was recorded, and after time was up, each group came together with their data and the varying numbers were graphed. These small duckweed ecosystems were affected by the light they were given since the light was not on for all eight weeks. The results could have been very different if a light was beaming on the duckweed for a longer period of time, or if the plants were given almost no unnatural light at all.
Data
All of the results from this observation of duckweed population growth varied between groups. Even though the volume of the duckweed habitat seemed as if it would be a limiting factor for the population growth, it didn’t seem to affect any cup the same. Group 1 and 2 both started with 10 duckweed plants, but group 1 ended with 94 and group 2 ended with 58. Another drastic difference was between groups 5 and 6, who both started with 20 plants. Somehow, the numbers of duckweed plants for these two groups after eight weeks was 64 and 160. Group 4 ended up double the amount of their corresponding group, with 89 compared to group 3’s 46. The biggest outlier was with group 8, with a whopping 268 duckweed plants after eight weeks. Somehow their 25 turned into a massive amount, while group 7 finished with only 52. The last group, group 9, stood by themselves, and increased their number from 35 to 69. All of this can be seen in the data table and the graphs below.
Duckweed Class Data
Data Analysis
The numbers recorded in week eight aren’t the height of the population for each group. Due to the carrying capacity, some of these organisms couldn’t go past a certain population number because of their limiting factors. Sometimes there isn’t enough of one or more resources for some organisms, and the lack of substantial needs stop them from expanding and increasing infinitely. This rule didn’t seem to apply to group 8, which never seemed to have any decrease in number during the whole investigation. As each week went by, the population growth rate showed to be linear. For example, the population number between weeks 1 and 2 is only eight duckweed plants, while the jump between weeks 6 and 7 is 52 plants. It is hard to tell why it resulted the way it did and stray so far from the others. It could be that the starting number was higher than other groups which allowed it to increase much more rapidly than the others. All the other graphs show to have a linear growth, followed by the s-curve when it reaches carrying capacity growth as well. The large drops occur in the cups that started out with larger numbers of duckweed. The two groups with 10 plants did not experience any sudden decrease in number, so the higher the starting number, the sooner the fall. Other than that, all of the graphs show no clear similarities with each other. They all have very scattered data with no obvious relationships.
Another important observation made within all nine groups was the community growing in each cup. As the duckweed grew in the spring water, it brought along an algae-like substance and gave the once clear water to a cloudy, greenish look. Somehow other organisms found their way into the ecosystem and grew alongside the duckweed which was not an expected event. This experiment also brought along fruit flies. Many groups found bugs in their cups which was unexpected since it did not occur during a previous investigation. It is not easy to tell if this community was made because of the placement of the cups or the amount of lighting given to the duckweed. Either way, it made the investigation more interesting as new factors were brought into the situation.
Conclusion
The prediction group 8 held was proven to be true. The graph for that cup is linear for the most part since it does not show a smooth curve. Nonetheless, it still grew at a quick rate. This growth applied to other groups, but they experienced drops in numbers due to carrying capacity and limiting factors and showed to have an s-curve after the linear growth. The most important environmental limiting factors for the carrying capacity for the duckweed was the surface area of the water and the nutrients contained in the water. Since duckweed is known to use up dissolved carbon dioxide, it used up its available nutrients very quickly, even after spring water was added to each cup when the water levels dropped. The surface area of the water really affected the duckweed growth. The plants rest on the top of the water and are never fully submerged. Because of that, the duckweed would not be able to continue to grow if it took up all the available space that the water’s surface provides.
Some errors that could have occurred would mostly be found in the counting job. They are very small organisms which make it difficult to get an accurate number. It could be a huge part in why all the groups have such varying data. Accuracy makes a huge different in precise experiments like this. If this investigation was to be performed again, it would be better if there was an easier way to keep the data as accurate as possible. Maybe other variables could be added, such as varieties in light, or different water or plants. How would duckweed respond to another species fighting for space and resources? Or what if there were too many or not enough nutrients in the water? One could only find out if they test more obscure variables.
If duckweed was placed into a lake and was introduced to an organism that eats it, the population could definitely decrease. However, duckweed is a very quick reproducer, so maybe it would be able to stay sustainable and keep a steady population number with a regular predator. If fertilizer was added to a duckweed habitat, it would cause the population to grow rapidly. Since duckweed drains carbon dioxide out of water, imagine what it could become with all the nutrients supplying it in the fertilizer. It is easy to come up with the answers to these situations from learning and understanding the relationship between population growth and carrying capacity to sustainability. Population growth can depend on the carrying capacity. Once a population reaches carrying capacity, it isn’t able to grow any more because it wouldn’t be sustainable if all the resources were used up right away. But population growth also is an indicator of the sustainability of an ecosystem. If there is a population growing at a steady rate, the ecosystem is sustainable since there aren’t any major factors working against it.
The numbers recorded in week eight aren’t the height of the population for each group. Due to the carrying capacity, some of these organisms couldn’t go past a certain population number because of their limiting factors. Sometimes there isn’t enough of one or more resources for some organisms, and the lack of substantial needs stop them from expanding and increasing infinitely. This rule didn’t seem to apply to group 8, which never seemed to have any decrease in number during the whole investigation. As each week went by, the population growth rate showed to be linear. For example, the population number between weeks 1 and 2 is only eight duckweed plants, while the jump between weeks 6 and 7 is 52 plants. It is hard to tell why it resulted the way it did and stray so far from the others. It could be that the starting number was higher than other groups which allowed it to increase much more rapidly than the others. All the other graphs show to have a linear growth, followed by the s-curve when it reaches carrying capacity growth as well. The large drops occur in the cups that started out with larger numbers of duckweed. The two groups with 10 plants did not experience any sudden decrease in number, so the higher the starting number, the sooner the fall. Other than that, all of the graphs show no clear similarities with each other. They all have very scattered data with no obvious relationships.
Another important observation made within all nine groups was the community growing in each cup. As the duckweed grew in the spring water, it brought along an algae-like substance and gave the once clear water to a cloudy, greenish look. Somehow other organisms found their way into the ecosystem and grew alongside the duckweed which was not an expected event. This experiment also brought along fruit flies. Many groups found bugs in their cups which was unexpected since it did not occur during a previous investigation. It is not easy to tell if this community was made because of the placement of the cups or the amount of lighting given to the duckweed. Either way, it made the investigation more interesting as new factors were brought into the situation.
Conclusion
The prediction group 8 held was proven to be true. The graph for that cup is linear for the most part since it does not show a smooth curve. Nonetheless, it still grew at a quick rate. This growth applied to other groups, but they experienced drops in numbers due to carrying capacity and limiting factors and showed to have an s-curve after the linear growth. The most important environmental limiting factors for the carrying capacity for the duckweed was the surface area of the water and the nutrients contained in the water. Since duckweed is known to use up dissolved carbon dioxide, it used up its available nutrients very quickly, even after spring water was added to each cup when the water levels dropped. The surface area of the water really affected the duckweed growth. The plants rest on the top of the water and are never fully submerged. Because of that, the duckweed would not be able to continue to grow if it took up all the available space that the water’s surface provides.
Some errors that could have occurred would mostly be found in the counting job. They are very small organisms which make it difficult to get an accurate number. It could be a huge part in why all the groups have such varying data. Accuracy makes a huge different in precise experiments like this. If this investigation was to be performed again, it would be better if there was an easier way to keep the data as accurate as possible. Maybe other variables could be added, such as varieties in light, or different water or plants. How would duckweed respond to another species fighting for space and resources? Or what if there were too many or not enough nutrients in the water? One could only find out if they test more obscure variables.
If duckweed was placed into a lake and was introduced to an organism that eats it, the population could definitely decrease. However, duckweed is a very quick reproducer, so maybe it would be able to stay sustainable and keep a steady population number with a regular predator. If fertilizer was added to a duckweed habitat, it would cause the population to grow rapidly. Since duckweed drains carbon dioxide out of water, imagine what it could become with all the nutrients supplying it in the fertilizer. It is easy to come up with the answers to these situations from learning and understanding the relationship between population growth and carrying capacity to sustainability. Population growth can depend on the carrying capacity. Once a population reaches carrying capacity, it isn’t able to grow any more because it wouldn’t be sustainable if all the resources were used up right away. But population growth also is an indicator of the sustainability of an ecosystem. If there is a population growing at a steady rate, the ecosystem is sustainable since there aren’t any major factors working against it.