Science Stuff

Scientific Method Task Cards

noreply@blogger.com (Amy Brown Science Stuff) — Mon, 20 May 2013 12:53:00 +0000

Have you tried task cards with your students?

Task cards are a fantastic way to reinforce lessons, review difficult concepts, or provide extra practice for the struggling student. The student reads each card, performs the task, and records his/her answer on an answer sheet, on notebook paper, or in their lab notebook.

There are many ways to use the task cards.

1. As seen in the photo above, punch a hole in the corner and place them on a ring. Hang them on a pegboard for use throughout the year. When reviewing for tests or exams, students can select the set of cards from the pegboard for the topic that needs the most review.

2. Set up a practice/review session by setting the cards up in a lab practical style. Place one card at each station and have the students rotate through the stations until all stations have been completed. My students love this format since it allows them to move about the room. The task cards in this format are a great way to give a quiz or test.

3. Use the cards in a game format. Divide the class into teams. Place the task cards face down in a basket. A team selects a card at random and must complete the task for a point.

4. Students can use a set of task cards in small groups and orally review one another for a unit test.

The task cards seen in the photo above are on the scientific method. The face of science teaching is changing. Common Core Science Standards, as well as the Next Generation Science Standards, are asking teachers to emphasis scientific concepts, rather than the memorization of large amounts of factual data. Instrumental to these new standards is teaching the student how to design and implement an experiment of their own. The first step in teaching the student-designed experiment is to provide the student with a complete and thorough understanding of the scientific method.

Most of the students entering my biology classes at the beginning of the school year can (in a very bored and monotone voice) recite the steps to the scientific method. What we as teachers need to insure is that the student can actually APPLY the scientific method.

Can the student read a passage and determine the independent and the dependent variables in the experiment?
Can the student identify the control and explain WHY it is the control?
Can the student look at a set of data and draw a logical conclusion?
Can the student design and implement an experiment?

I have a free PowerPoint and set of notes that you can use as a starting point in your teaching of the scientific method. This free product can be viewed and downloaded here. Once your instruction is complete, you might want to give these task cards a try. I most often use the cards in a lab practical format. Students rotate through the various stations and complete the task at each. An example of one of the task cards is seen below.

The set includes 30 task cards. Some of the "tasks" include:

Writing a hypothesis.
Distinguishing between the experimental and control groups
Identifying the independent and dependent variables.
Drawing a conclusion based on given data.

Be sure to follow up your lessons on the scientific method by having your students design and implement an experiment of their own. You can check out my blog post on student designed experiments by clicking here.

Thanks for stopping by!

Click above icon to go to my TpT store.

Analysis of Local Ultraviolet Radiation: An End of the Year Web Quest

noreply@blogger.com (Amy Brown Science Stuff) — Mon, 13 May 2013 15:01:00 +0000

Need an end of the year activity that will benefit your students for the rest of their lives?

The dangers of ultraviolet radiation are well known. The effects of ultraviolet radiation on living organisms should be ingrained in each and every science student passing through our classes. UV radiation is just a small portion of the energy from our sun that bombards the Earth. Thankfully, the Earth is wrapped in a protective blanket, the ozone layer, that prevents much of the ultraviolet radiation from reaching Earth's surface.

Many of my students arrive in my biology class at the beginning of the school year confused about the differences between ozone destruction and the greenhouse effect. They know that both involve our atmosphere in some way, and that both are bad for the Earth, but the distinctions between the two concepts are often blurred.

Ozone is a molecule composed of three atoms of oxygen. The ozone layer is found in the upper atmosphere and protects the Earth by absorbing UV radiation from the sun. Without this protective layer around the Earth, live on Earth would perish. Unfortunately, human activities are reducing the amount of ozone found in the atmosphere.

What effect will this have on the living organisms of Earth?

An increase in the number of malignant skin cancers.
An increase in cataracts.
Changes in plant physiological and developmental processes.
Reduced survival rates of phytoplankton in the oceans.

As we send our students off for the summer, let's make sure that they understand the dangers of prolonged exposure to the sun. At the end of each school year, I do an activity called, "Ouch That Burns! Analysis of Local Ultraviolet Radiation." In short, this is a web quest that allows the student to track the UV Index in their area over a period of time.

The EPA maintains a web site in which an individual can look up the ultraviolet radiation index each day for his/her area. I have prepared several pages of worksheets that students will complete while they are visiting the EPA website.

In this activity students will:

Determine the UV Index for their local area.
Record data for the UV index over a period of time.
Determine the areas of our country that suffer from the highest UV indexes.
Gather data for UV indexes in their area over a period of one year.
Plot the data on a graph to show how the UV index changes throughout the year.
Determine the most dangerous time of year in their local area.
Determine how the UV Index has changed from years past.
Compile a list of health hazards to the living organisms on Earth.
Answer final analysis questions.

The three-page student handout has complete directions, questions, data tables, and graphing grid. There is an accompanying 2-page teacher answer key.

This is a fun and informative activity that will greatly supplement your lessons on ecology, ozone depletion, and human influences on our delicate biosphere. And, hopefully, we will teach our students to not only protect the earth, but to protect themselves from the harmful effects of ultraviolet radiation.

I am very passionate in my teaching of ecology and the environment. All of my ecology-related products can be viewed here.

Have fun teaching!

YIKES!! The AP Biology Exam is Tomorrow!!

noreply@blogger.com (Amy Brown Science Stuff) — Sun, 12 May 2013 13:15:00 +0000

I guess I should calm down now. It is Sunday, Mother's Day, and the day before the AP Biology Exam. I should calm down, but my nerves are a wreck. There is nothing more that I can do today to help my students. I feel out of control because it is no longer in my hands.

I have 81 students who will be sitting for the exam in just about 24 hours from now. They are a GREAT bunch of kids!! I have worked them to death this year, and I never heard a single complaint from them. They are a hard working bunch and they want to do well on the exam.

But who knows exactly what this new AP exam will be like?? We have worked many a math problem and I feel really good about that portion of the exam. I am a bit (no, a lot!) nervous about only having 63 multiple choice questions, and I sure hope I have adequately prepared my students for the newly revised free response section.

I have a competitive personality. I know this is not MY exam score, but the student's exam score. But after working as hard as we have worked this year, I NEED the satisfaction of knowing that all of the hard work has paid off. I'll be on pins and needles until those scores come in.

We still have 2 weeks of school left after the AP exam. I really LOVE this time of the year. My now "old" students will help me pass out books and summer assignments to the "new" students coming in next year. We will walk up to the pond next to our school and feed the gazillion turtles that live there. And watching the movie, GATTACA is always a favorite end of the year treat.

Good luck to all of my students on the exam tomorrow!! Make me proud!!

Population Genetics: The Hardy Weinberg Equation

noreply@blogger.com (Amy Brown Science Stuff) — Thu, 09 May 2013 14:00:00 +0000

This fun lab simulation should guarantee that your students understand the Hardy Weinberg Principle!

(I hope!)

I talk to a lot of biology teachers. Everyday. Some are in my school, some are at other schools in my district, others I know "virtually" from various message boards that I read and post to. Through these communications, I have come to realize that many biology teachers do not include the Hardy-Weinberg Principle in their lesson planning.

I know that all biology teachers have their own "order of events" but for me a unit on genetics, followed by my unit on evolution is perfect. In fact, I would be hard pressed to do it any other way. The Hardy-Weinberg Principle is the link between genetics and evolution. It is the proof that we offer to our students that populations are constantly changing and evolving. It allows us to mathematically show that the frequency of a particular allele in a population can change over time.

Simply put: Evolution is any change in the frequency of alleles in a population. Evolution is the result of changes in the gene pool. Two men, G. H. Hardy and W. Weinberg, proposed a mathematical model for detecting changes in the gene pool.

The Hardy-Weinberg Principle states: “In the absence of mutation, migration, and natural selection, and in a population that is sufficiently large, the frequencies of alleles will remain the same.”

The Hardy-Weinberg Principle is represented in the equation:

No population is free of these agents of change. The Hardy-Weinberg equation is used to detect changes in the population from one generation to the next. Since no population in nature is free of mutations, migrations, and natural selection, and since mating is rarely completely random in nature, of what value is the Hardy Weinberg Principle? It allows us to detect changes in the gene pool, and therefore, determine that a population is in a state of change....Evolution!

My experience with my own students is that some of them have a little trouble grasping this concept. After introducing the topic and working through quite a few practice problems, I do a simulation lab.

Lab: Population Genetics, The Hardy-Weinberg Principle, and Evolution

Purpose:

1. To simulate how changes in the gene pool might occur by using the class as a breeding population of individuals.

2. To observe how the Hardy-Weinberg equation is used to detect changes in allele frequencies in a population.

Materials: PTC test papers, Calculator, Allele cards, Coins, Pencil and paper

Safety Precautions: None

The student handouts for this lab are numerous.....12 pages! I usually run off a class set and have students record all of their information on notebook paper. I use the class set throughout the day, and then I file them away for use the next year.

I have also included an 11-page teacher guide. The teacher guide has tips and tricks for making the lab successful as well as answers to questions and solutions to problems. Sample data is included to give you an idea of what to expect in the simulation.

Students begin the lab by determining the frequency of an allele in the class population. I like to use PTC paper to determine if students are tasters or nontasters. But if PTC paper is not available, you can choose another trait such as the presence or absence of dimples, or the ability to roll the tongue. From the number of recessive individuals in your class, the value of q can be determined. From that point, the students will determine what percentage of the class is homozygous dominant and heterozygous for the given trait.

Next, students will run three simulations: (1) Testing the Hardy-Weinberg Principle, (2) Testing the Hardy-Weinberg for Selection Pressure, and (3) The Heterozygote Advantage.

Students will begin the simulation as heterozygous individuals and will use allele cards to generate offspring. Students proceed through several generations of "mating" and the data is used to test the different conditions of the Hardy-Weinberg Principle.

During each simulation, students will determine the frequency of the dominant and recessive allele and note how the frequency of p and q change in various scenarios. The lab concludes with follow up questions and 8 additional practice problems involving the Hardy-Weinberg equation.

The end result? My students have mastered the concept and are able to work problems involving the Hardy-Weinberg equation.

Good luck, and have fun teaching!

Lab: Population Genetics, The Hardy-Weinberg Principle, and Evolution

Teacher Appreciation Day Sale, 2013

noreply@blogger.com (Amy Brown Science Stuff) — Sun, 05 May 2013 13:30:00 +0000

Thanks Teachers!!

Happy Teacher Appreciation Week!!

TeachersPayTeachers.com celebrates Teacher Appreciation Week by having one of the biggest sales of the year!

My entire store will be 20% off.

My sale includes all digital downloads as well as all CD's and books.

Use the discount code provided by TpT (TAD13) at checkout and you will receive an additional 10% off all purchases.

Teachers,

Thanks so much for all you do!!

Super Secondary TpT Giveaway!

noreply@blogger.com (Amy Brown Science Stuff) — Wed, 01 May 2013 03:34:00 +0000

Next week is Teacher Appreciation Week. So here it is early.....

Happy Teacher Appreciation Week!!

Thanks to all of you teachers out there!! I have had a fantastic school year, and I hope you have, too! In celebration of Teacher Appreciation Week, I have teamed up with a fantastic group of secondary teachers to offer a lucky winner a fantastic prize of 40 different teaching lessons/materials. Many thanks to Danielle Knight (Author of the blog, Study All Knight) and Brittany Wheaton (Author of the blog, The Super Hero Teacher) for organizing this fantastic giveaway.

So without further ado, let's get started! The contest begins on May 1st and ends on May 6th. The winner will be announced on Monday, May 6th!
(The contest has been extended one day to Monday, May 6.)

Good luck!

Here are the 40 products that compose this amazing prize package:

$10 gift certificate to The SuperHERO Teacher's TpT store

$10 gift certificate to Study All Knight's TpT Store
20 Fun Warm-up Writing Prompts - Summer Idioms with Photos by Diana Bailey

Algebra Slope and Y-Intercept Task Cards by Teaching High School Math

Mother's Day Gift Craftivity and More by Janet Rainey

Creative Exit Passes For Any Subject! Effective Formative Assessments by Presto Plans

Creative Activities for Any Novel or Story by Tracee Orman

A Separate Peace Close Reading Study Guide by Wohls

The Mother Nature Awards for Planet Earth by Science Stuff

Winner's Choice! from Lovin Lit

Plato's REPUBLIC Quiz #2 and discussion questions (Book I 331E-336A) by Linda Jennifer

Health-Smoking Assessment by Innovative Teacher

Fraction, Decimal, Percent War Game by Danielle Krantz

Fearless - our most popular empowerment tune by I am Bullyproof Music

winner's choice from The Traveling Classroom

Holocaust Timeline Activity by Michele Luck's Social Studies

Literary Criticism Powerpoint for Beginners by Tara Armstead

Essay Writing Trivia Game by The Classroom Sparrow

Kingdom Taxonomic Card Sort Manipulative by Bond with James

Por y Para: All in Spanish Handout and Worksheet by Night-Light Lessons

Japanese Internment Camp Human Rights Activity- by Different Drummer Secondary Resources

Writing: Voice, Audience, and Purpose by Darlene Anne

Interactive Student Notebook by Chalk Dust Diva

Solving Equations Color By Number Bundle by 4 the Love of Math

How to Write Powerful Thesis Statements by Dianne Mason

Kickin' High Tops & Sneakers Clipart by Glitter Meets Glue Designs

Shakespearean Slam/Flattery Contest Materials by Laura Randazzo

Eight Parts of Speech PowerPoint by HappyEdugator

Circulatory system lab and foldable pack by Tara L (Science in the City)

Starry Night - the painting and 2 poems by Poetgrl78

Frankenstein Analysis Question Package by Adam Horowitz

Factoring Polynomials "Spin to Win" Game! by All Things Algebra

Igneous Rocks Common Core Mini Bundle by Michael Giovacchini

Chemical Bonding Go Fish by The Science Vault

Disagree without Bullying by Ellen Weber

Sub Plans for Any High School Class-10 Motivating Articles Activity by Mrs. S

End of Year Math Activities for Middle School by Lindsay Perro

Welcome to Middle School {End-of-the Year Activity} by Right Down the Middle with Andrea

One Year of Daily Warm Up Questions for US History by Students of History

Tragic Lovers from Literature Made Happy By You! by Special Education- Peggy Simpson

Good Luck Everyone!!

a Rafflecopter giveaway

Springtime is the Perfect Time to Teach the Plant Kingdom!

noreply@blogger.com (Amy Brown Science Stuff) — Tue, 23 Apr 2013 23:38:00 +0000

Introduction to the Plant Kingdom

Complete Teaching Unit

(Bundle of Products)

By far, the most popular items in my TpT store are my complete unit plan bundles. These unit plan bundles contain everything you need to teach a thorough and complete unit to a typical biology or life science class. All of my unit plan bundles come with a colorful and engaging PowerPoint presentation, notes for the teacher, notes outline for the student, several labs, homework assignments, daily quizzes, crossword puzzles for vocabulary review, review PowerPoints, and a final unit test.

I have just recently completed my latest unit plan bundle. It is called "Introduction to the Plant Kingdom." No biology class is complete without a survey of the Kingdom Plantae. In short, life could not exist on earth without the plants. Plants are the producers in every food chain. Plants carry out photosynthesis, producing organic compounds from inorganic compounds. The plant uses much of this glucose as a source of energy, but a portion of the glucose is passed up the food chain. This sustains life on earth. Not only do plants produce food for all heterotrophs, they also provide the oxygen that fills our atmosphere.

Simply put, this is one of the “must-teach” topics in a biology class!

This complete teaching bundle contains 10 separate products bundled into one digital download. When appropriate, I have included each product as a Word document, and I have also included each product in PDF form. Each of these products is sold separately in my TpT store, but buying the entire unit in one download will save you money. If these products were purchased separately, the total cost would be $30.00. I am selling this bundled package of products for $19.99.

All products have answer keys included.

The bundled unit contains the following. Details of each product can be found below.

1. A 97-Slide PowerPoint with Notes for Teacher and Student

2. A 130-Slide Review PowerPoint

3. Lab: Liverworts, Mosses, and Ferns

4. Lab: Transpiration in Plants

5. Lab: Diversity in the Plant Kingdom (A Living Plant Lab)

6. Homework Question Packet of 99 questions

7. A Set of 3 Quizzes

8. A set of 2 Crossword Puzzles

9. Graphic Organizer Study Aid

10. Unit Test of 100 Questions

CLICK ON PICTURE TO VIEW LISTING IN MY TPT STORE

Topics covered by this Unit:

1. Introduction to Plants: Importance of plants to life on Earth, definition of a plant.

2. Plant life cycle: Alternation of generations, sporophyte and gametophyte generations, haploid and diploid phases, the production of spores by meiosis, flow chart showing alternation of generations.

3. The Transition of Plants to Land: The algae were the first plants on earth, evidence that algae are the ancestors to the land plants, advantages to a life on land, challenges to a life on land.

4. Cladogram showing the evolution of mosses, liverworts, ferns, gymnosperms, and angiosperms from ancestral algae.

5. Traits of the True Land Plants: Alternation of generations, spores produced by sporangia, multicellular gametangia, apical meristems, vascular tissue, nonmotile gametes, root system, protection from dehydration.

6. Classification of Land Plants: Vascular and nonvascular land plants, bryophytes, tracheophytes, seedless plants, seed plants, gymnosperms, angiosperms, monocots and dicots.

7. Flow chart showing the classification of the land plants.

8. Bryophytes: Characteristics of bryophytes, examples of bryophytes, explanation of why the bryophytes are still tied to a watery existence, bryophytes are nonvascular plants, bryophytes have a dominant gametophyte generation.

9. Example: The Liverworts. Characteristics of liverworts, students will draw and label the structures of a liverwort, liverwort life cycle.

10. Example: The Mosses. Characteristics of mosses, students will draw and label the structures of a moss, moss life cycle.

11. The Seedless Vascular Plants: The evolution of vascular tissue, the importance of xylem and phloem, why ferns are classified as seedless vascular plants.

12. Characteristics of ferns, students will draw and label the structures of a fern, fern life cycle.

13. The Seed Plants: Seed plants are the dominant plants on earth, two groups of seed plants, gymnosperms and angiosperms, the advantage of having a type of reproduction free from water, adaptations seen in the seed plants, cones and flowers, pollen, seeds, the evolution of seed plants.

14. Characteristics of gymnosperms.

15. Characteristics of angiosperms.

16. Comparison of monocots and dicots.

Below I have listed each product with a brief description. I have included a hyperlink to each individual product. You can click on the links below to view a complete and thorough description of each product and download a free preview of the product.

Introduction to Plants PowerPoint with Notes for Teacher and Student

It consists of 97 slides that are colorful, informative and visually stimulating. Pictures and diagrams are included that will greatly enhance your instruction to your students. This product also includes a set of notes for the teacher (12 pages) and a set of notes in outline form for the student (17 pages). Graphics, diagrams, clip art, and photographs were chosen to capture the attention of the student as the lesson is being taught.

Set of 3 Quizzes

This product contains 3 quizzes that can be used at various stages as the unit is being taught. I always break up the content into manageable amounts of study material and give my students several small quizzes on this material prior to the unit test.

Homework and Study Guide

This document is a 9-page student worksheet consisting of 99 questions. As I am teaching my introductory unit on plants, I assign a portion of these questions for homework each night. This document provides quality homework assignments and ends up being a completed and thorough study guide for the unit test.

PowerPoint Review Questions

This PowerPoint consists of 130 slides of questions and answers and provides an excellent review for the chapter test.

Slide Lab: Liverworts, Mosses and Ferns

This is an in depth lab that looks at the structures of mosses, liverworts, and ferns. You will need quite a few prepared slides to be able to do this lab. Students are asked to compare Bryophytes to Tracheophytes and will discuss which are truly adapted to life on land and why.

Lab: Plant Transpiration

Purpose:

1. To measure the amount of water lost from the leaves of a plant over a given amount of time.

2. To calculate the surface area of leaves on a plant.

3. To calculate the rate of transpiration from the leaf under different environmental conditions.

Lab: Diversity of the Plant Kingdom (A Living Plant Lab)

In this lab, students will circulate through 8 different lab stations. At each station, the student is required to make a drawing and answer 5 to 8 questions. The eight stations are as follows:

Station #1 Living Mosses

Station #2 Living Ferns

Station #3 Fern Gametophyte

Station #4 Living Gymnosperm

Station #5 Pine Pollen

Station #6 Living Angiosperm with Flower (dicot)

Station #7 Living Angiosperm (monocot)

Station #8 Fruits

Set of 2 Crossword Puzzles

I love crossword puzzles and I use them all the time in my biology classes. Crossword puzzles are a great way to reinforce and review the many, many vocabulary words covered in a biology class. Crosswords not only help with strengthening vocabulary, they also provide invaluable spelling practice.

Graphic Organizer Study Aid

This is a simple study skill graphic organizer that I use with my Biology students to help them prepare for the unit test. The student will compare and contrast the traits found in liverworts, mosses, ferns, gymnosperms, and angiosperms.*NOTE: This is one of my FREE items in my TpT store. Even if you do not purchase this unit plan bundle, please download this freebie!!

Unit Test

This unit test has 100 questions. There are 63 fill in the blank questions, 11 matching questions, and 26 multiple choice questions.

This final link will return you to the product-listing page on TeachersPayTeachers.com.

Happy Teaching!

Introduction to Plants: A Complete Unit Plan

Genetics in the Laboratory

noreply@blogger.com (Amy Brown Science Stuff) — Wed, 17 Apr 2013 02:38:00 +0000

Do you want to do a great genetics lab with your students, but don't have time for fruit flies?

Having enough "time" is an issue for me every single year! I finally had to come to the realization that my fruit fly genetics lab would have to go. It is such a great lab, but just too time consuming.

Now we grow corn! It only takes a few minutes to plant and you are practically done! I do have my students water their corn every few days, and in about 2 weeks we are ready to do the lab.

In corn, green stem (due to chlorophyll production) is dominant over albino stem. I order seeds that are the F-2 offspring of heterozygous parents. The expected ratio when the seeds grow is, of course, 3/4 green stem and 1/4 albino stem. Students then compare the expected ratios to the actual number of each type of offspring observed.

For an added component to the lab, have the students consider the effect of the environment on the expression of the gene. When the seeds are first planted, I have half the class place their trays on a table in front of a window. The other half of the class place their trays in a cabinet in complete darkness. When the seeds finally sprout and grow, we compare the number of albinos grown in the dark to the number of albinos grown in the light.

For those plants grown in the light, the results are fairly close to the expected 3:1 ratio. But, the seeds grown in the dark are a different story. 100% of the seeds grown in the dark turn out to be albino.

After this first observation, all trays are left in the light for 48 hours, and a second observation is made two days later. Miraculously : ) about 3/4's of the albinos from the dark trays have now turned green.

Students quickly determine that the environment plays a very important role in gene expression.

If you choose, you can order seeds showing two traits as seen in the photo to the left. When these seeds were grown, students could determine the expected and actual numbers of green and albino stems as well as the number of tall and dwarf plants.

You can view this lab in my TpT store by clicking this link:

Lab: The Effect of the Environment on Gene Expression

Earth Day Activities for Grades 2 - 12

noreply@blogger.com (Amy Brown Science Stuff) — Wed, 10 Apr 2013 21:02:00 +0000

Part of our responsibility as science teachers is to teach our science students how to be good stewards of the environment. I think the first step is to get our kids excited about the living organisms that inhabit this planet. As a biology teacher, I do this every day! Each day in my class, I throw out a bit of fun trivia, or discuss the characteristics of an unusual creature or show a 1-2 minute video from youtube. I do this each and every day. It only takes a couple of minutes, and then we move on to the lesson of the day.

But now we are to the time of the year that we need to start thinking about some special activities for Earth Day. I have developed a set of PowerPoint slides that I call "The Mother Nature Awards for the Planet Earth."

Here is an example of one of the slides:

Each slide has a photograph (or two) of an unusual plant or animal, followed by 4-6 fun and interesting facts about that living organism. The response from my high school students is quite good. They really enjoy hearing about my "award-winning" creatures.

These are suitable for grades 2 - 12.

For the younger kids, I developed a set of activity worksheets. The listing for grades 2-5 comes with a set of activity worksheets (42 pages) for the students to complete as the PowerPoint slide is being viewed. The finished worksheets can be put together to make a great Mother Nature Award book.

The listing for grades 6-12 comes with a worksheet for students to conduct their own research to develop a PowerPoint slide for a Mother Nature Award of their own choosing. This makes a nice homework assignment for a grade, or for a great extra credit opportunity.

And finally, students of all ages can enjoy this FREE PowerPoint that I created on the history and the background of Earth Day.

Whatever you decide to do for Earth Day, just make sure the students understand how important it is that we all work together to save Planet Earth.

Happy Earth Day!

Earth Day Freebie! A History of Earth Day

noreply@blogger.com (Amy Brown Science Stuff) — Sun, 07 Apr 2013 13:50:00 +0000

Earth Day

April 22

Most of our students know that we celebrate Earth Day "sometime in the spring", but do your students know the origin and history of Earth Day?

The first Earth Day was organized by Wisconsin senator Gaylord Nelson, and was held in 1970. Since that first observance of Earth Day, it has turned into a global event that is recognized by millions around the globe. I prepared a 25-slide PowerPoint for my biology students to teach them about the history, background, and origin of Earth Day. This is a FREE download and all are welcome to use it in your classrooms. It is suitable for children of all ages.

What is Earth Day?

(Click Here For Free PowerPoint!)

Enjoy this freebie......

.....and Happy Earth Day!!

Free Monohybrid Genetics Practice Problem Worksheet

noreply@blogger.com (Amy Brown Science Stuff) — Tue, 26 Mar 2013 19:50:00 +0000

Gregor Mendel

Who Doesn't LOVE Genetics?

In my many years of teaching, it has been a very rare occasion to have a student in my class who did not enjoy my genetics unit. It is such a fun and interesting topic to teach! My students always love to discover if they have a widow's peak, a hitch hikers thumb, or a crooked little finger. And, of course, what kid hasn't been rolling (or trying to roll!) his tongue for most of his life?

Thanks to the work of Gregor Mendel, the very scientific Austrian monk, the study of genetics began in his abbey garden in the mid-1800's. By spending many years in the patient breeding of pea plants, Mendel provided the world with the basic laws of genetics that we still use today.

I would bet that every biology teacher today begins with the story of Mendel. From Mendel's work we can teach such vocabulary words as trait, hybrid, gene, alleles, dominant, recessive, segregation, homozygous, heterozygous, genotype and phenotype. As soon as these terms are mastered, we jump into Punnett squares and probability.

For some teachers, this is where our trouble begins. No, it is not that the material is hard or that students fail to master it. The problem lies within the biology texts that are commonly used today. It seems that they have precious few practice problems available to our students. Having spent many, many years in the biology classroom, I have collected quite a few great genetics problems that I use for practice material.

One of my favorite worksheets is called Monohybrid Mice! (FREEBIE!!) Before more complicated problems can be attempted, the student must be able to complete a very simple one-factor problem... the monohybrid cross. This simple worksheet has just four problems. The student completes the Punnett square, fills in a chart of genotypes, phenotypes and probabilities, and finishes the problem by answering a series of questions. I called this Monohybrid Mice! because all of the problems deal with the coat color of mice.

You can download this worksheet for free from my store on TeachersPayTeachers.com. Once your students have completed this exercise, they will, no doubt, be ready to master more complicated problems.

Enjoy the freebie, and good luck with your teaching!

Muir Woods National Monument: The Coast Redwood Trees

noreply@blogger.com (Amy Brown Science Stuff) — Sun, 17 Mar 2013 18:47:00 +0000

Guest Blogger: My Own Daughter!

I am blessed to have the two most wonderful daughters in the whole, wide world! My oldest, Faith, just returned from a trip to San Francisco. While there, Faith had the opportunity to see one of the things on MY bucket list .... the Coast Redwood trees. She graciously agreed to write a blog post about her experience in the Muir Woods National Monument. So without further ado, here's Faith!

Faith with Kate (dear friend and
awesome roommate!)

This past week, I went on a trip with my scholarship group to San Francisco. We toured all over the city for four days and saw all the sights from the Golden Gate Bridge to Chinatown to Berkeley and more. We had a blast everywhere we went, but I think my favorite part of the trip was visiting Muir Woods.

As you can tell from the rest of my mom’s blog, we’re pretty big on nature in this family, so I was pretty psyched that this was included on our trip.

Friend Zack

A few facts about Muir Woods: Muir Woods is a remnant of the ancient coast redwood forests that covered much of the northern California coastal valleys before the 1800s. Today, it is located twelve miles north of the Golden Gate Bridge.

150 million years ago, redwood-like trees covered much of the Northern Hemisphere. Due to climate change, the range of the redwood tree is much diminished. Today, there are two species of redwood in California, the coast redwood and the giant sequoia. The coast redwoods are found in Muir Woods and on a thin, discontinuous strip of land 500 miles long from southern Oregon to Big Sur. The giant sequoias are found in small groves on the west slope of the Sierra Nevada.

The tallest redwood in Muir Woods is 252 feet tall, but the tallest in the world is 379.1 feet tall and is located in Redwood National Park. This makes the redwood the tallest living thing in the whole world. The tallest redwood is also up to 2,000 years old (though the average mature redwood is 600-800 years old)! Its bark is a foot thick and its diameter is up to 22 feet. The reason the redwood trees reach such incredible age and size is largely due to their incredible bark. The bark grows from six to twelve inches thick and protects the tree from insects, fungi, and even fire. Repeated hot fires can burn through the bark and cause hollows in the tree, but even then the redwood survives.

Fire actually plays a fairly important role in the life of the redwood. Fire clears the forest floor of smaller plants and debris so that new redwood seeds can reach the ground and take root. Furthermore the forest fires recycle nutrients and turns debris into ash. In the 1800s, local towns and cities began suppressing these fires and upsetting the natural cycles of the forest. The wildfires that would occur every 20-50 years were an integral part of the life cycle of the redwoods. Nowadays, the National Park Service conducts prescribed burnings in order to re-establish fire’s natural role in the forest.

Redwoods are conifers and reproduce via cones. If a cone finds purchase in warm, moist soil it may germinate and root. A seedling may grow two or three inches in its first year of life. However, in well-established forests such as Muir Woods, burl sprouting accounts for most reproduction of the redwoods. A burl (pictured below) is a mass of dormant buds that grows at the base, roots, or sides of the tree. When the tree is injured or the burl is affected, the burl may sprout which gives the redwoods great competitive advantage over other trees that reproduce by seeds only.

Another fun fact about redwoods is that they occasionally grow in family circles. This process that takes hundreds of years. When a redwood is fatally damaged, it will send up hundreds of burl sprouts. Over time, only a handful of them will reach maturity. These mature surviving trees often take root in a circle around the old, dying tree, forming “family circles.”

Muir Woods is a specialized forest environment that provides the habitat for a range of flora and fauna adapted to low light and moist conditions. Such undergrowth includes redwood sorrel (pictured to the left), sword ferns, and mosses. Bay laurels and big-leaf maples find purchase in rare patches of sunlight. Douglas firs are interspersed among these other trees. The animals of the forest include deer, spotted owls, bats, raccoons, warblers, kinglets, thrushes, garter snakes, rubber boas, and California giant salamanders. The most common are Steller’s jays, Sonoma chipmucks, gray squirrels, and slimy bright banana slugs (in the rainy season).

Though we were there on a dry day and did not get to see any banana slugs, the woods were simply amazing. We had spent a hot day in San Francisco the previous day and were shocked to find that the woods were downright cold and very wet. We thoroughly enjoyed our two mile walk through the woods, and I highly recommend it to nature enthusiasts young and old alike!

For more information visit the Muir Woods website.

Free Graphic Organizer for Comparing Groups of Living Plants

noreply@blogger.com (Amy Brown Science Stuff) — Thu, 14 Mar 2013 14:00:00 +0000

Click photo to see all of my
plant products in my TpT store.

One of my goals of late has been to spruce up, improve and update the quality of my teaching materials on plants. No changes had to made to the content. I love teaching plants, and I was already doing a great job with the content. I just wanted to make my materials more attractive and more visually appealing for my students.

So what's new? I have made a very picture-ific 97-slide PowerPoint presentation, added some crossword puzzles, a set of PowerPoint review questions, and some new daily quizzes. I have plans for new homework assignments, study guides, and a few new labs I want to try out. My problem is that I have more ideas than I have time to carry them out! All in good time, I guess.

At any rate, one of the new things I have just created is a graphic organizer for comparing and contrasting the major groups of living plants. When a lot of new material has been covered, my students sometimes struggle with remembering all the details. A teaching tool that never fails to work is a graphic organizer. When the content is logically organized and put into place, studying by the student becomes much more effective.

I have listed this new graphic organizer for plants in my TpT store. It allows the students to compare the liverworts, mosses, ferns, gymnosperms, and angiosperms. It is a freebie, so be sure to click the links below and grab a copy for yourself. I hope you find it useful.

Graphic Organizer: Comparing Groups of Living Plants

Preparing for the New AP Biology exam

noreply@blogger.com (Amy Brown Science Stuff) — Tue, 12 Mar 2013 14:00:00 +0000

This post is going to be extremely short! I recently received a newsletter from Carolina Biological that had a great article called, "Earning a 5: Successful Test Taking Strategies for the New AP Biology Exam." I thought the article was great, and I immediately shared it with all of my students.

If you are a teacher of AP Biology, I think you might find the article useful. Click here for a link to the article.

Good Luck!!

AP Biology Review PowerPoints are available in my TpT store.

Enjoying Nature!

noreply@blogger.com (Amy Brown Science Stuff) — Mon, 11 Mar 2013 01:31:00 +0000

We had a gorgeous Saturday in my neck of the woods. It was sunny and 70 degrees. I spent the day doing a cemetery clean up project with a local ladies group. My high school aged daughter joined us, and I enjoyed spending the lovely day out of doors with my daughter and friends. We raked up many months worth of magnolia leaves from our local historical cemetery.

As we raked, I discovered a very pretty patch of bracket fungi....

The bracket fungi are also called shelf fungi. They belong to the phylum Basidiomycetes, along with the mushrooms, puffballs, stinkhorns, jelly fungi, smuts and rusts. Shown in the photos are the fruiting bodies. They are generally tough and sturdy and produce their spores within pores of the fruiting body. Most shelf fungi, like many of the fungi, are decomposers, and can easily be found growing on dead trees and other dead plant matter. Other shelf fungi are parasitic, and grow along the sides of living trees.

Also spotted were some lovely lichens growing on the sides of some very old trees. Lichens are composite organisms. Two species live together in a lichen in mutualistic harmony. One of the organisms is a photosynthetic alga, and the other is a species of fungus. The alga carries out photosynthesis and provides the fungus with food. The fungus has the ability to absorb water, and provides the algae with an adequate water supply.

Lichens can be found in nearly every habitat on earth. They are particularly susceptible to environmental changes and are often an indicator of air pollution in an area. If the lichens are not thriving, there is sure to be a reason. Lichens are also used to make dyes and perfumes.

Lichens: Informational Text, Critical Reading, and Lab Activity

Who Doesn't Like Free Teaching Materials??

noreply@blogger.com (Amy Brown Science Stuff) — Thu, 07 Mar 2013 20:47:00 +0000

Free!

As teachers, this is music to our ears! Every teacher I know, spends part of every pay check buying materials for school. We buy school supplies such as pencils and paper for those students who never seem to have either. We buy workbooks, textbooks, and fictional books for our classroom libraries. We buy snacks and hand over lunch money to the student who "forgot" his. We pay to take classes and to go to workshops to make ourselves into even better teachers. For the lab, I am constantly purchasing soap, paper towels, graph paper, colored pencils, seeds, potting soil, plants.....well, this list is never ending.

So what can you get for free??

There are quite a few blogs that offer free teaching materials for teachers. I would like to tell you about a few that offer free materials for all ages and all subject areas. I know that there are sure to be many more than those listed here. But these are the ones I have been personally involved in.

1. <------ May I start with my own freebies? Just take a look to the left side bar. I have a long list of items that you can download for free from my TpT store.

2. Take a look at the blog called "The Cornerstone". Angela puts together a monthly link up of free materials. They are organized by grade level so you can easily find the materials you need.

3. "Creativity in the Common Core Classroom" features free materials that are aligned with the common core standards. A new list of freebies is posted each and every Friday. These, too, are organized by grade level.

4. I am proud to be a contributor to "Classroom Freebies." There are 100 teacher/authors contributing to this collaborative blog. Everyday, there are so many ideas being posted. Many are for elementary classrooms, but keep scrolling down because there are quite a few middle and high school contributors. This blog was so popular that Charity started a second, little sister blog, called "Classroom Freebies, Too!" It also has a hundred contributors and a tons of freebies.

5. Next, check out "Taking Grades for Teachers." Margaret generously features everyone's freebies, but her own, I think. Each week, Margaret searches and finds great free, downloadable materials and features them on her blog.

I am so grateful to all of these wonderful friends who have listed many of my free items on their blogs.

Now for the biggest source of free materials?? Well, that would be TeachersPayTeachers.com. As of this writing, there are 85,319 products that are listed for free. Click this link, then click the big button that says "FREE".

Enjoy! And Have Fun Teaching!!

Leaf Pigment Chromatography

noreply@blogger.com (Amy Brown Science Stuff) — Mon, 25 Feb 2013 21:42:00 +0000

Our Biology I students just finished up a lab in which the leaf pigments are separated by paper chromatography. It might seem like an odd time of year to be studying leaf pigments and photosynthesis, but our school runs a trimester system, and a student might be in any given semester of a class at an odd time of the year....... A discussion topic for another day!

As I am writing this, it has occurred to me that I have written on this topic before. I just took a look back through all of my old blog posts, and I have indeed discussed this topic previously! Now that I have re-read that old post, I am pretty pleased with how it turned out. Check out this link to the previous post, and I will not cover the same content again:

Past Post on Paper Chromatography

Here are some new pictures that I took as my students were working on their lab.

Spinach leaves are placed in a mortar and pestle along with a little acetone. Students grind the leaves until the acetone turns a dark green. A small piece of capillary tubing is used to transfer drops of the pigment extract to a piece of chromatography paper.

When enough drops have been placed on the chromatography paper to make a dark green circle on the paper, it is ready to be placed into a large 25x200 test tube.

The large test tube has about 1/2 inch of petroleum ether in the bottom of the tube. The pigments will immediately begin to separate.

Here is the finished chromatogram:

Here is the lab that I use with my students:

Click picture to see product.

AP Biology Exam: Teacher In Panic, Students Oblivious

noreply@blogger.com (Amy Brown Science Stuff) — Mon, 18 Feb 2013 00:07:00 +0000

<-------- The teacher feels

like this.....

.....and the students feel

like this! ----->

Sound familiar?

It is the time of the year when the AP Biology teacher (me) begins to panic. There are only "x" number of teaching days left, and there is still "y" amount of material that must be covered! PANIC!

Actually, my students are great. But it is getting on toward spring time in my part of the country. The students are tired....very tired! They have worked hard all year, participated in a ton of extracurricular activities, and they are just worn out!!

It is a difficult time of the year to be sure. I must continue to teach hard everyday to get all of the material covered. At the same time, I need to get my students motivated for reviewing for the exam. It is a fine line to balance. Push them hard, but don't overload them.

I am fortunate to have a 70 minute class period. (Don't kill me....I realize how lucky I am!!) Starting this week, we are going to spend the first 15 to 20 minutes of each class period reviewing. I have written a set of review PowerPoints to use just for this purpose. These are not teaching PowerPoints. They are simply slide after slide of questions and answers. I generally let the students get into groups and make a game out of it. The group getting the most questions correct wins a prize. Little Debbie Snake Cakes are a particular favorite award for my students.

Freebie: Here is the link to one of my review PowerPoints that I have in my TpT store. It is on organic compounds. You can easily delete some of my slides and add more slides of your own.

Click picture to download.

If you like the free PowerPoint, you might be interested in my entire set of 25 different review PowerPoints.

How many days are left before Monday, May 13??? :)

Daphnia, Daphnia, How do I Love Thee?

noreply@blogger.com (Amy Brown Science Stuff) — Mon, 11 Feb 2013 14:39:00 +0000

Let Me Count The Ways (of Measuring Your Heart Rate!)

Valentine's Day does not have to go unnoticed in our high school biology classes! We might not discuss the emotional affairs of the heart, but we can definitely discuss the physiology of the heart!

Each year, during the week of Valentine's Day, I take my biology students to the lab to measure the heart rate in the crustacean, Daphnia. Since Daphnia is an ectotherm, its heart rate will vary with changes in its body temperature. (I also pass out a few Dove chocolate hearts along with the lab supplies!)

First we place the Daphnia into a small, water-filled chamber like the one seen in this photo. A few strands of cotton fibers placed in the chamber helps to restrain the Daphnia while viewing!

A Petri dish is filled with ice water, and the Daphnia viewing chamber is placed on top of this ice water to cool the internal body temperature of the Daphnia. After a minute or two, the Daphnia is placed under a dissecting microscope, and the fun begins!

Some students have difficulty at first, finding the heart. Since the exoskeleton of Daphnia is clear, the heart is easily seen. Once the students find the heart, they are ready to start counting the number of heart beats per minute.

After repeating three trials at the ice water temperature, students fill the Petri dish with water that is at room temperature and repeat. Finally the students fill the Petri dish with warm water to finish the experiment. The data from the experiment is fairly consistent from year to year, and students can quickly conclude that the heart rate of Daphnia speeds up as the temperature increases.

My favorite part of the experiment comes on the next day! On day 2 of this lab, I have my students design their own experiment. They are asked to design an experiment to test the effect of caffeine and alcohol on the heart rate of Daphnia. The students must state a hypothesis, describe their experimental and control groups, carry out the experiment, collect their data, graph their data, and come to a conclusion based on their data.

For my honors level and AP Biology students, I have them complete this worksheet to determine the Q10 Temperature Coefficient.

This lab, along with all of the worksheets and a teacher guide, has recently been added to my TpT store. You can view it here:

Measuring the Heart Rate in Daphnia

Biology Careers Mini Posters - A Freebie!

noreply@blogger.com (Amy Brown Science Stuff) — Tue, 05 Feb 2013 22:40:00 +0000

What can you do as a career if you love Biology?

The answer is "Lots and lots of things!!" Career week is a really big event at my high school. I was asked to put together a display illustrating some of the many careers that are possible in the field of biology, so I made a set of 26 mini-posters. Each poster highlights one career. There is a picture of a person "doing the career" as well as a very brief description of the career.

I am sharing these as a free download in my TpT store.

Click on this link ---> Biology Career Posters <--- to download these for free.

These will make a great display in your classroom!

Give the Kids a Brain-Break!

noreply@blogger.com (Amy Brown Science Stuff) — Fri, 01 Feb 2013 15:29:00 +0000

<----- What I DON"T want to see in my class!

Over the years of teaching I have come to realize that some topics are very difficult for my students. I find that the students learn and perform much better if I teach in spurts. I teach a new concept for 15-20 minutes, and then I give my students a "brain-break". What is a "brain- break"? I am glad you asked!!

A "brain-break" is a 2 or 3 minute break away from the topic currently being taught. It is a couple of minutes where the student can relax, and it relieves the tension of a very complex lesson. I am still a teacher who wants every minute to count. So during a "brain-break" I usually throw out a bit of science trivia. These are just fun and interesting facts that teach the student about the amazing natural world we live in. Over the last few months my "brain-breaks" have consisted of the Mother Nature Awards for Planet Earth.

Here is an example:

These are PowerPoint slides. I insert one of these slides into a PowerPoint on cellular respiration or photosynthesis or enzyme-catalyzed reactions. My students have come to expect these little surprises and they get so excited when one of these pops up into my otherwise overly technical lecture. This is fun, it teaches a bit about the wonders of nature, and best of all, it gives the student just a minute to relax and get focused again before I launch back into the real topic of the day.

After a slide has been viewed, I print it, laminate it, and place it on the wall in my classroom. I have been very pleasantly surprised at how often students stop by the wall to look at the Mother Nature Awards.

I have put together a group of 20 of these awards and placed them in my store on TeachersPayTeachers.com. There are two product listings, one for Grades 2-5 and a separate listing for grades 6-12.

The listing for grades 2-5 comes with a set of activity worksheets (42 pages) for the students to complete as the PowerPoint slide is being viewed. The finished worksheets can be put together to make a great Mother Nature Award book.

Don't forget that Earth Day is coming up soon. The Mother Nature Awards are a perfect Earth Day activity.

Have fun teaching!

My Favorite New Toy!

noreply@blogger.com (Amy Brown Science Stuff) — Thu, 24 Jan 2013 13:19:00 +0000

I have a confession to make......

......when I use a PowerPoint presentation in my classroom, I love to use a lot of animations.....

Okay, I have said it!

I recently got a feedback from one of my buyers suggesting that I remove all of the animations from my PowerPoint presentations. He wanted all the items on a slide to be visible at one time. But I couldn't disagree more! I only want my students to see what I want them to see at any given point in my lesson. I do not include a lot of moving parts (as you see here), but I do limit the amount of information the student can see. As I am teaching, I want the student to focus ONLY on what I am currently teaching. When it is time to move one, then a few clicks gets the students to the next point in my lesson. This prevents the student from simply copying from the PowerPoint without listening to the explanation. If the student can only see one sentence at a time, then that is all they can copy! I get to determine when they should write more information in their notes.

So, now I am getting to the point of this blog post. I, too, was a prisoner to my computer. I like to walk around and pace while I am teaching. This is hard to do if you have to constantly click from your computer keyboard to get to the next PowerPoint slide.

The solution? Buy a clicker! I recently bought the

"Kensington 33374 Wireless Presenter with Laser Pointer" to use with my computer. It has changed my life! I cannot say enough good things about this product! It is so simple to use. Simply insert the receiver into a USB port on your computer and you are ready to go. Not only can you click through your PowerPoint with ease, but it also has a laser pointer that can be used to direct your student's attention to a particular part of a slide. The receiver is inserted at the base of the unit for easy storage.

The cost was around $40, but it may be the best money I have ever spent.

Can I Make Protists More Interesting For My Students?

noreply@blogger.com (Amy Brown Science Stuff) — Thu, 17 Jan 2013 14:30:00 +0000

When a biology teacher says to the class, "Today we are going to start our unit on the algae, followed by a unit on the protozoa," the collective groan from the class can be deafening. Nothing can be worse to a high school kid than studying algae! Well..... maybe studying the fungi is worse, but not by much!

My solution? Excitement!! I must be a real science nerd, but I really, really like teaching this topic. And when I get excited, my students (mostly) get excited, too.

The Protista Kingdom contains all organisms that cannot be classified as fungi, true plants or animals. The range and variety of organisms in this kingdom is huge! Some protists are more closely related to plants, fungi, or animals than they are to other protists. Biologists cannot agree on how to classify these organisms, and some scientists have now split the Protista Kingdom into as many as 20 different kingdoms. The term "protist" is still used as a convenient way to refer to eukaryotes that are neither plants, animals, or fungi.

This school year, I wanted to give my unit on protists a little extra punch. I wanted to make it as visual as possible, so I put together a brand new PowerPoint presentation that covers both the algae and the protozoans. Wow! It ended up being 99 slides long with handouts for my students of 19 pages. I did break this up into two units of study, though. I first covered the algae and gave a unit test on just algae, followed by a unit on protozoans.

I packed the PowerPoint with color and as many cool photographs as possible.

Once taught, this is material that needs reinforcement if I expect my students to remember it on test day. I made a second PowerPoint that is just slide after slide of review questions. My high school students like review games, so I put them into small groups and made a contest of it. I would project a question and each group would take a turn at the answer until the question had been answered correctly. I kept score and awarded a box of Little Debbie Santa Claus Brownies to the winning group.

And finally, we finished it all up with a lab on the living protists. My students love to watch anything that moves under a microscope. I purchased a culture of Paramecium, Euglena, Amoeba, Diatoms, Spirogyra, Volvox, and Stentor (my personal favorite!) Oddly enough, my students really enjoyed a mixed culture of 6 algae that came with a dichotomous key. They had to find the 6 different algae in the culture and name them using dichotomous classification key.

All in all, the unit on Protists was not as bad as it seemed at first. Most students escaped unharmed.

Kingdom Protista PowerPoint With Notes for Teacher and Student

Kingdom Protista Review PowerPoint

Lab: The Living Protists

New Blog: Creativity in the Common Core Classroom

noreply@blogger.com (Amy Brown Science Stuff) — Mon, 14 Jan 2013 22:51:00 +0000

I would like to give a shout-out to a great new blog!

As you can see, this blog is called Creativity in the Common Core Classroom, and is written by two amazing and talented teachers, Brian and Eric. Their purpose? To maintain a vibrant, dynamic, meaningful and fun learning environment while meeting the new Common Core Standards.

Each Friday, this blog features free products that you can download and use in your classrooms that meet the common core standards. The free resources are divided into grade levels: K-2, 3-5, and 6-12. I am extremely honored to be the first featured teacher in the 6-12 grade level section. Be sure to check in each Friday for a new set of free teaching materials that are common core aligned.

Lab: Making Coacervates

noreply@blogger.com (Amy Brown Science Stuff) — Mon, 07 Jan 2013 00:10:00 +0000

Two activities in one:

A guided lab activity plus a student designed lab activity!

I just tried this lab for the first time this year. And I liked it so much that I will definitely use it again next year!

Each school year I make myself try new and different activities. The idea of this lab has been around for a long time, and when I finished teaching my unit on "The Origin of Life on Earth" I though I would give this lab a try. The lab is called "Making Coacervates."

What are coacervates? Coacervates are simply droplets that are composed of molecules of different types. Coacervates are not alive, but they do share some of the same characteristics as those found in living cells. Because of this, many scientists have hypothesized that structures similar to coacervates may have been the precursors to the first living cells. Although the origin of life has not been duplicated in the laboratory, it is very simple to observe the formation of coacervates. This activity was a thought-provoking one for my students. They clearly were able to see, using a microscope, how it is possible for molecules to come together to form cell-like structures.

This lab kills two birds with one stone! The first part of my lab was a guided lab activity. The students followed a lab procedure that I gave them to test the effect of different pH levels on the formation of coacervates. But the second day of the lab packed a much bigger punch!! I assigned each lab group a different variable to test. The group had to form a hypothesis and then design a lab to test their hypothesis. For example, some groups had to test the effect of temperature on coacervate formation, while other groups tested the effect of changing solution concentrations on the formation of coacervates.

Six different variables were tested by the students. At the conclusion of their experiment, each student group had to make a very short report to the class discussing the results they obtained. This is a time consuming activity, but it is time well spent! Common Core standards are demanding that science students spend more time in analysis, problem solving activities.

I am particularly proud of my 5-page handout that I designed for my students to use as they designed their experiment. I required them to form a hypothesis, write a procedure that would gather quantitative data, design a control for the experiment, describe their experimental and control groups, graph their data, form a conclusion, and much more.

Materials needed: Glass test tube with cap, Graduated cylinders, Gelatin solution (protein), Gum Arabic (carbohydrate), Glass stirring rod, pH paper, .1M HCl solution, Dropping pipets, Microscope, Test tube rack, and Microscope slides. Additional materials are needed for the student designed experiments.

What are the pros and cons of this lab?

Pros include:

Students gained a better understanding of coacervates and how they might have formed in the seas on early Earth.
Materials list is simple and inexpensive.
Teaching students how to design and carry out a controlled experiment is a MUST in the science classrooms of today.

Cons include:

This lab takes a bit of time. Students completed the guided activity in one class period, they wrote and designed their experiment in a second class period, and they carried out their experiment in a third lab period. Some parts of the lab report had to be completed as a homework assignment.
The coacervates are very easy to find under the microscope, but they are difficult to count. The student has to scan the entire slide and count the number of coacervates that were formed. This is a source of error.

This lab was used as a conclusion to my unit on "The Origin of Life." Some of the materials I used to teach this unit can be found here:

Origin of Life PowerPoint and Notes for Teacher and Student

Origin of Life Review PowerPoint

Origin of Life Quizzes