Teaching Plan for Biodiversity Lessons

by Cindy Cohen

 

1. The topic of the investigation and suggestions for communicating findings. There are three topics of investigations. The first one is approximately one 40 minute lesson in length, while the the second and third will probably take about two lessons.

Investigation #1: How can we use a dichotomous key to determine the characteristics of hominids?

Investigation #2: How can we use different Winogradsky columns to determine the effects of abiotic factors on an ecosystem?

Investigation #3: How can we describe various problems affecting biodiversity? How can we find solutions to these problems?

 

The findings can be communicated in the following ways:

1. Students can present their answers in the form of a report spoken in front of the class.

2. The completed investigations can be placed on a bulletin board.

3. A monthly newsletter can be made regarding the outcomes of experiments and other things which happen in my classes.

4. Since the second two investigations lend themselves to many combinations of possible correct answers, students can form groups, exchange results, and attempt to account for differences in these results.

 

2. Context: Description of your educational setting. I teach in Newtown High School, a public high school located in Corona, Queens in New York City. It has about 4800 students, many whom are recent immigrants from all over the world. The labs have been renovated two years ago. There are several computers available, and there is usually access to water, gas, and other basic equipment and chemicals.

Investigation #1 may interest students because people are generally interested in their origins. They may also want to examine how other people are different from themselves and guess who is who.

Investigation #2 may interest students because they generally like to nuture organisms and observe their progress. I have observed students becoming emotionally attached to diverse organisms from pea plants to paramecium.

Investigation #3 may interest students because most people care at least a little about the environment and want to do something to help.

It may be easier to present the remaining sections of the assignment lesson by lesson.

 

Investigation #1: How can we use a dichotomous key to determine the characteristics of hominids?

Key ideas: Individual organisms change over time.

Present day species developed from earlier species.

Extinction of a species occurs when an organism is no longer adapted to its environment.

 

Standards addressed: S2c, S4a, S5f, S6d, S7b

 

This lesson, although primarily one dealing with human evolution, relates to biodiversity in two ways. The first is that humans have also possessed a diversity of species in the past, because evidence suggests that for most of human evolution, more than one species of hominid walked the earth. Since the other types of species went extinct, we can address the issue of extinction, what it means for humans and other organisms. The second is that the use of a key is a widely used method of classifying species, which is an important component of biodiversity.

 

Motivational questions: 1. How are video games from the early 1980's (like Pac Man and Space Invaders) different from the ones around today?

2. What are some things which are commonly used today which were not widely available fifty years ago?

For both questions, students should realize that the changes did not take place at once, but slowly over a longer period of time. Similarly, students should realize that evolution consists of slow change over a long period of time.

 

Introduction: Like all other living things, humans have evolved, or slowly changed from earlier types of organisms to the way we are today. Over the last three million years, we have changed from animals very similar to apes into people. The group of animals consisting of humans and their closest relatives are called hominids. All hominids walk upright and have a larger brain, unique jaw, and other distinctive features. In this assignment, you will examine information about various types of hominds and attempt to identify them based on a key.

 

Vocabulary: organism, hominid, evolution

 

Procedure/Observations: Below are five paragraphs. Each paragraph describes a hominid. Using the key following the paragraphs, determine the identity of each hominid.

 

Hominid #1: I lived between 250,000 years ago and 1.5 million years ago. I used tools and fire. I and people like myself lived in Asia, Africa, and Europe. Who am I? ____________________ Why do you think so?

________________________________________________________

__________________________________________________________

 

2. I lived between thirty thousand years ago and 130,000 years ago. I used tools, fire, built shelters made of rocks, and buried people who were dead. I and people like myself lived in Asia, Africa and Europe. Who am I?

__________________ Why do you think so? ______________________

___________________________________________________________

 

3. I lived between two and three million years ago. I was the first hominid to walk upright. I did not use tools. I lived in Africa. Who am I? ____________

Why do you think so? __________________________________________

____________________________________________________________

 

4. I and people like myself began to appear about thirty thousand years ago. We live all over the world. I wear clothes, make paintings, and build shelters out of rocks, wood and animal hides. Who am I? _____________________

Why do you think so? __________________________________________

____________________________________________________________

 

5. I lived between 1.6 and 2.2 million years ago in Africa. I used tools, but I did not use fire. Who am I? _____________________________________

Why do you think so? _________________________________________

___________________________________________________________

 

                                  Key to Help Determine Who is Who

1. Did the hominid use tools?

    If yes, go to questions 2.

    If no, the hominid is an Australopithecus.

2. Did the hominid use fire?

    If yes, go to question 3.

    If no, the hominid is a Homo habilis.

 

3. Did the hominid live less than 250,000 years ago?

    If yes, go to question 4.

    If no, the hominid is a Homo erectus.

 

4. Did the hominid build shelters?

    If the shelters were only from rocks, the homind is a Neanderthal.

    If the shelters were from other materials in addition to rocks, the hominid is a Homo sapiens.

 

Note: Students will not need to examine all of the evidence from each organism in order to determine which one is a hominid. Similarly, scientists do not need to examine every characterisitc an organism possesses in order to classify them. They only need as much information as necessary to divide them into groups.

 

Conclusion questions:

1. All five species are hominids. Name two things all hominids have in common.

2. Name something all of the members of the genus Homo have in common.

3. Name something members of Homo erectus and Homo sapiens have in common.

4. All of the hominids except for Homo sapiens have gone extinct. Why do you think this has happened?

 

Investigation #2: How can we use Winogradsky columns to determine the effects of abiotic factors on an ecosystem?

Key ideas: 6.1a, 6.1d, 6.1e

Standard addressed: S2e, S3b, S4a, S5a, S5f, S7a, S7b

 

Motivational questions: 1. What are some things which are microscopic? Students are probably familiar with microscopic organisms like ameba and paramecium. What they may not realize is that microscopic organisms can be found on the land as well.

2. What would happen if garbage was never removed? The bad smell and the lack of space would make life unpleasant. Similarly, If there were no decomposers, ecosystems would be overrun with dead organisms.

 

This investigation would be introduced in the second or third day of an ecology unit. Students need to be familiar with the concepts of producers, consumers and decomposers in order to understand what is happening in the Winogradsky column and why. Completing this investigation would require one lesson to set up the columns, one lesson to analyze the results, and half a lesson once each week in order to monitor their progress.

 

Introduction: Every ecosystem needs producers, consumers and decomposers if it is going to be successful and last a long time. Although they are very small and easy to ignore, decomposers are important because they return the nutrients of dead plants and animals to the environment so they can be used to help new organisms to grow. This lab has two goals:

1. You will be growing decomposers so they can be present in large enough numbers for you to see them.

2. You will be comparing columns which are grown in different types of environments. This way you can see how different abiotic factors such as water, nutrient and air content affect the growth of different living things in an ecosystem.

 

Vocabulary: producer, consumer, decomposer, ecosystem, abiotic factor

 

Materials: soil, sand or mud from various places, large graduated cylinders or glass bottles (16 ounces or larger), color pencils or magic markers, masking tape, paper, chalk, epsom salt (magnesium sulfate), egg

water, plastic wrap, rubber bands

 

Procedure: 1. Place paper and one of either the chalk, epsom salt, or egg at the bottom of the glass bottle.

2. Fill the bottle with soil or sand (preferably from only one place) until it’s about 3/4 full.

3. If the soil is dry, add enough water so that all of the soil is moist.

4. Cover with the plastic wrap and seal it with the rubber band.

(It is very important to seal it in such a way so that gases may escape.)

5. Label your column with: a. your name b. your date   c. the origin of the soil or sand d.what substances were added.

6. Carefully examine your column and complete all of the following:

a. What is the height of the soil in your column in cm?

b. Do you see any living things in your column? Why or why not?

c. Draw your column in COLOR.

7. Answer the three questions above once a week for four weeks.

8. At the fifth week, the results of each column are presented to a class and a chart is made comparing the results. The chart may look something like this:

 

group    type of soil   substances   height                   results

 

 

Conclusion questions:

1. The different colors which appear on the column indicate the growth of microscopic organisms. Which column had the most growth? Which column had the least growth? Why do you think this has happened?

2. How were the organisms which grew in each column the same? How were they different?

3. What are some factors which affect the growth of organisms in an ecosystem?

 

Investigation #3: How can we describe problems affecting biodiversity? How can we find solutions to these problems?

Key ideas: 6.2a, 6.2b, 6.3c, 7.1, 7.2, 7.3

Standards addressed: S2c, S2d, S2e, S3e, S4d, S4e, S5e, S5f

 

Motivational questions: 1. How is the air and water in New York City different from the air and water in a forest? The air and water found in a forest would be (we hope) less polluted. The better quality would be due to a smaller human impact on the environment.

2. What are some problems facing the environment? What are some possible solutions? Students may be familiar with problems like acid rain and the greenhouse effect and the need to use less gasoline and elelctricity.

 

This investigation would be given to students at the end on the unit pertaining to biodiversity. This is because students need to be familiar with a variety of concepts in order to understand the exhibits, such as ecosystem, extinction, limiting factors and habitats.  

 

Introduction: This assignment can be an assignment for a class trip or for students who wish to work independently to receive extra credit or to compensate for work they have missed. In order to complete this a assignment, a person needs to go to Hall of Biodiversity in the Museum of Natural History. The answers to all of these questions are found in a section of the musem called Resource Center which deals with problems and solutions facing the environment. It is towards the end of the exhibit that has the giant squid hanging from the ceiling. (If you cannot find the giant squid, ask someone to show you.) Once you find the giant squid, walk across the hall with the squid behind you (NOT through the rain forest or wall of life) until you get to a small movie screen. You are now ready to begin.

 

Procedure:

1. Watch the introductory film about biodiversity. A. What is biodiversity?           B. Give three examples of organisms biodiversity includes. C. Why is biodiversity important?

Now you are prepared to examine the rest of the exhibit. When you finish the film, turn so that you are facing the sign that says Resource Center, and the giant squid is to your right and a little behind you. The signs and displays on the right side describe problems facing the environment, and the ones on the left side describe solutions.

2. Look at the sign on the right side labeled Extinction and Biodiversity Loss.  A. According to the chart, how many species have gone extinct in the last five hundred years? B. Why is this an inexact calculation of the number of extinct species?

3. Look at the sign on the right side labeled Cultural Extinction. A. What is cultural extinction? B. Why is this a problem?

4. Look at the display on the left side labeled Protection and Restoration. In 1-2 sentences, name and describe 3 places which are being preserved.

5. Look at the sign on the right side labeled Damage to Salt and Fresh Water. Why are there problems in the Aral Sea?

6. Find the display on the left side called Management for Biodiversity. In 1-2 sentences, name and describe two things people are doing to help the environment.