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Using Biology to Teach Children to Think Like a ScientistbyEmily Dentel
Students asking good questions? Even getting my students to ask a question can sometimes be daunting. So when the seminar Asking Questions in Biology: Discovery versus Knowledge came up I was immediately interested. I teach 2 nd grade in a school with students of low income families. Many of my students come to me with their natural curiosity about the world stifled. It's not that they don't want to know or are not curious. Rather, it is more that they just don't want to ask questions. Many of them come from homes that answers are not given and questions are discouraged either because parents don't take the time or don't know the answers themselves.
My goal for this curriculum unit is to reignite student's natural curiosity and empower them to ask questions, as well as teach them how to ask good questions. Our Biology topic is Life Cycles. We will observe the life cycles of butterflies, frogs, and chickens in our classroom. Students will keep science notebooks 1 to record observations, questions, class discussions, research findings and experiments. We will introduce and utilize parts of the Scientific Method and develop an understanding of what it means to think like a scientist. The new Common Core State Standards 2 will lend to connecting science and literacy allowing for more effective use of classroom time. A list of standards utilized in this unit can be found following the classroom activities.
I want to emphasize the time table needed and flexibility of this unit. My class will be working with this unit throughout the year, as we will have three different animals to observe over the course of the school year. However, this unit can be utilized on various timetables based on what time is available in your school schedule. If you wish to bring an animal into your classroom there are several insects whose life cycles can be observed in a matter of weeks. Also, you should not believe that you must commit to having a small zoo in your room to utilize this unit.
I understand not all districts will allow animals into the classroom. Many of the websites provided in the resource section have videos and activities that would be sufficient for students to gain knowledge and understanding of various life cycles. One weblink even demonstrates a variety of projects that a Kindergarten class undertook in the study of butterflies. This unit can also be utilized with older students by focusing on the ideals of a scientific notebook to gain a basic understanding of the scientific method. The science notebooks can be used with all age groups to link literacy and science. I intend to use the science notebook with all of the science topics we study this year, and not simply for the life cycle lessons outlined here.
Objectives - Science and Literacy
In an effort to incorporate Common Core Standards I will be utilizing some of the Common Core for reading and writing in conjunction with some Oklahoma State Science Processing Standards 3 as well as a few Oklahoma State Life Science Standards. This will also allow me to utilize our required reading and writing times to build upon the 30 minutes allotted each day for science or social studies.
Throughout this unit students will represent and describe the stages of the life cycle. Students will also be able to describe how the baby or young animal is similar or different from its parents. I chose butterflies, frogs and chickens as they are allowed in the classroom by my district, are available for purchase and I have a continuing plan for the animals once they have reached adulthood. I also opted to physically have the animals in my room rather than simply watching videos and reading books in an effort to not only engage students' curiosity, but also to stress the students' individual responsibility by having them help with the care and upkeep of the animals in our classroom. This will also give students more of a personal stake in their learning and exploration of animal life cycles.
Students will observe the stages of the life cycle and record their observations in a Scientific Notebook. Students will arrange animals or insects and their stage in the life cycle in a serial order. Students will utilize observations to make inquiries about the animals or insects we have in class or other organisms they self-select. Students will also use their inquiry skills to work through some of the steps in the scientific method. To accomplish these objectives students will utilize their scientific notebook. Each student will be charged with maintaining their own scientific notebook to record the following: personal or peer observations through written explanation and drawings, personal or partner research from books, the internet or videos, facts they are curious about or questions other students ask, answers they discover or information that is presented by other students, interesting facts, notes from classroom discussions.
Students will engage in meaningful discussions with the entire class or in small groups. Discussion will focus on their observations, predictions, questions and findings they have recorded in their notebooks. Students will self-select an animal's life cycle different from the ones researched in class. Students will read informational text as well as utilize online resources to read and research their selected animal. Then, utilizing the data recorded in their notebooks, students will create a presentation on the animals they chose to research. Students will have the option of how they wish to present their information. However, there will be a required- text portion as well as a visual aspect. Computer lab time and writing time will be utilized for students to create a poster or media presentation of their findings to the class. If students are comfortable they will also be given the option to share their information with our other partner kindergarten class. This will allow students to continue to work on their oral presentation and speaking skills. These objectives will assist in meeting state standards and Common Core Standards in multiple areas of reading and writing skills.
Thinking like a Scientist?
What does it mean to think like a scientist? Simply put, it means that you ask questions. However, it is in the seeking of answers that you truly begin to think like a scientist. Before this seminar I simply assumed that scientists like to be right (and they do). However, they also quite enjoy being wrong or more accurately proving something is wrong. Whether that something is their idea or someone else's idea it doesn't seem to matter. For the Scientist it is about discovering new unknowns to explore rather than simply finding the yes or no answers. The unknown could be more answers to their questions, it can be more questions that take them in various different directions or it could be a discovery of information they didn't think to look for in the first place.
This idea seemed strange to me until I read Royston M. Roberts book "Serendipity Accidental Discoveries in Science" 4 in which he shares various accounts of how many of the major discoveries in science were accidents, from Columbus's "discovery" of the Americas to the uses of vaccinations and Velcro. Many of these "serendipitous discoveries'" happened either while the scientist was looking for the answer to a very different question or simply by accident. Who would have thought that an apple falling from a tree would lead to the Theory of Gravity? This book helped me realize just how important it is to ask questions, but that it is even more important to pay attention to all of the small details along the way. If you have time it is an easy read, and really kind of humorous to see how many of the things that we think were great discoveries, in fact were actually just happy accidents.
I will be utilizing several of the examples from this book to show my students that to think like a scientist the purpose of asking a question is not just to find a single answer, but to explore all the unknowns you find along the way. For example I am new to town and I need to get to the grocery store from my house. I discover there are three easy ways to get there and that one may be shortest, but each time I go I take a different route so that I can learn more about where I live. Each route I take I find something new; a gas station that has better prices, a gift shop that I will want to go back and explore later, a branch of my favorite coffee shop, possibly even a whole different grocery story that I like even more. All of these possibilities for further exploration that I would never had known if I was only happy to go one way and not pay attention to what was around me.
That is what a scientist does. Then they go back and explore all the little items of interest they find along the way. One question leads to so many more questions or unknown areas to explore. I want my students to not be so focused on answering a single question that they miss all the interesting facts and discoveries around them. To my surprise, it turns out science is not so much about answering questions, but instead about discovering what we don't know yet.
What is Inquiry Science?
Throughout my reading there seems to be a few guiding ideals in the various views of what Inquiry Science 5 is and what it should look like. One of those is that inquiry is essentially questioning and looking for an answer. In a classroom, however, this will look different based on each teacher's ability to carry out true Inquiry. It can be very time consuming and at times initially costly. With good planning, a little forethought and some organization I believe it can work well in any classroom setting.
One main ingredient in Inquiry Science is that students have a personal stake in their learning. They have the freedom to select the information they wish to study and learn about as well as direct the research and path they will take to get there. Don't get me wrong they don't have all the power. A second grader will not be working on physics while a sixth grader learns about a frog life cycle. As the teacher we set the parameters for the learning that will take place. My students will be working on life cycles because this is a skill my state requires them to learn in second grade. Students will observe the three different life cycles I have selected to have in our classroom. However, they will self-select two other animals that they will research independently or with a partner. It will be my job to keep them on task while at the same time allowing them to explore ideas or topics that pop up along the way.
These different topics are where the inquiry piece truly comes into play. It is difficult to foresee what all of these may be, but one example is that someone decides to look more deeply into the adaptations of various animals. There are some fun and crazy facts that students could also want to explore. I will need to plan for and organize enough time throughout the year to make sure students have the freedom to follow these different paths. The scientific notebooks will assist in this process as well. I will set aside reading time every other week (I can change this as I go if needed) for students to research through the internet, informational text and reference books the topics they wish to explore personally. They will then make notes, illustrations and log ideas for further inquiry in their notebooks. This will allow me to not only meet some of the Common Core Standards for reading and writing but also to utilize time from my reading and writing schedule. By having this flexible time with reading, writing and science I will be able to provide students with the time required for their independent inquiry research and activities.
The Scientific Method
The steps to the scientific method can vary based on grade level and individual needs. The following is a list which includes all the steps in correct order. First develop a question, and use this question to develop a hypothesis. The hypothesis should be in the form of a statement. The next step is to predict how you will prove or disprove your hypothesis. Once you have a prediction you will test or perform an experiment to discover whether your hypothesis is correct. Finally once you have all your results you will analyze your data to determine the outcome of your experiments.
As a teacher, I practice a form of the scientific method in the classroom. I observe and evaluate the needs of our students, and predict ways I can meet those needs. Then I test to see if the needs are met. If the need is met I move on to the next skill, and if not we reassess to create a new prediction or plan. I continually evaluate whether what I am doing is working and make changes accordingly continually adjusting my practice to meet student's needs. However, my understanding of the scientific method was much more rigid. I did not realize the constant flow of research, evaluation, and adjusting that can and should happen in the scientific method. It should also be mentioned that through this research I have found various steps in the scientific method; some have more than I outline here and some omit a step or two.
The formulation of a question is the first step in any scientific journey. The eye opening moment for me was there is truly no end to the scientist's journey. Even when an answer is found for a scientist it is simply a means to look for the next question. But what question? How do you know what to ask? The simple answer is you research, read, and observe the world and your environment. When you find something that is interesting you look at what information is available or already known. What have other scientists found to be true or false? What information is not already known about your topic? It is in the unknown that scientists look.
From the original question and subsequent research a hypothesis is formed. A hypothesis is simply a guess about how something will work. It is a reworking of the question into a statement. It should state what the outcome of an experiment will be. For my second graders I would give them a fill in the blank sentence like; If I __write the action you will do____, then ___write what you think will happen___. It will be important for me to remind my students not to be afraid to guess. A scientist is just as happy to prove something wrong as they are to prove something right.
Once the hypothesis is formed it is important to return to the research you have already done and then allow the hypothesis to guide you through more research and observation to devise a prediction. The prediction is how you will prove your hypothesis. You can have more than one prediction to work through, but it is important to note that once a hypothesis and a prediction are complete they should not be changed. Otherwise you will not be able to prove if your hypothesis is right or wrong.
Now it is time for the "fun" part: the test or experiment. At this point students will add to their known research by recording what they observe from the testing. This gives them the data or information to be able to prove their hypothesis true or false. From the experiment students will analyze their data and draw a conclusion stating what their experiment has told them about the hypothesis. It is at this point the scientist could go back and try a different procedure; the more data or "proof" you have to back up your hypothesis the better.
Although these are the steps in the scientific method I want to stress the fact that this is not the end of the journey. For a scientist it is only the means to ask another question and then begin the quest for more information.
The three main life cycles I will focus on for this unit are the butterfly, frog and chicken. I selected these three animals because we will be able to physically have them in our room to personally witness the changes each animal makes in going through their individual life cycles. It is important to note that I have made sure that not only can I have these animals in my classroom but I understand what will happen with them as we complete our unit of study. Please check with your local regulations on the ability to obtain or release any animal you may wish to study in your classroom.
In an effort to fully meet the goals of encouraging my students to ask questions and inquire about our world we will be studying other animal life cycles based on student's interest and their personal research. I am open to the idea of having other animals in my room but it will be up to the students to research all the necessary facts about care and shelter and what to possibly do with the animal at the end of our school year and over breaks. This will not only give students a personal stake in their learning but help them to see that scientists must look to effects of their experiments as well and the consequences they may or may not have on the environment and to themselves personally. I will be keeping the frogs in my class until they complete their life cycle in death and the chickens will be going home with me to live.
Not everyone will be able to have animals in their classroom for students to experience firsthand the life cycle. If that is the case there are many books available, free videos on youtube and teachertube, and other videos are available for purchase and posters with illustrated and live photos. The teacher resources section of this unit is a sample of what is readily available.
I selected butterflies for several reasons; one being they are simply the easiest to care for. I will be using the Painted Lady Butterfly. They look similar to the Monarch and are available for purchase with or without a habitat online. They can be ordered and arrive as larva, if you are lucky one may still be in the egg. They are left in the container they arrive in along with their food until they go into their pupa stage and form a chrysalis. Then you simply move them to the larger habitat and provide sugar water for them to eat. They can be kept or released into the wild. Butterflies are insects: they have three body parts consisting of a head, thorax and abdomen. They also have 3 sets of jointed legs and most insects have wings and antennae. Butterflies have all these characteristics and they go through a complete metamorphosis, meaning they pass through four distinctive stages of development; egg, larva, pupa and finally adult. This makes them especially dramatic for students to observe and document.
The first stage of a butterfly life cycle is the egg. They are very small and can be round, oval or cylindrical in shape. Some butterfly eggs are so transparent you are able to see the embryo move inside. This will not be observable in the classroom as they normally arrive already in their larval stage; however there are video clips available that show the larva eating its way out of its egg. In nature butterflies will usually lay their eggs on or near plants to give the larva the food source they will need to grow. The eggs are sticky so they will be secure and stay on the plant they are laid on.
The second stage is called larva or more commonly for butterflies caterpillar. The main job of a caterpillar is to eat. In fact that is almost all they do; they will eat their way out of their egg, eat the leaf their egg was on and move on to more leaves. The caterpillar will need to store energy from the food to get it through its metamorphosis phase and then continue on to reproduce. Butterflies only live a short time, many just a month but some can live up to a year. So they must mature and reproduce quickly. As the caterpillar grows it will "molt" or shed the outer layer of soft exoskeleton several times. This stage will only last a week or so. Some caterpillars will create silk webbing to protect it and to assist in movement.
The third stage is the pupa or chrysalis. Once the caterpillar has completed its growth, it will suspend itself from a leaf or branch using silk thread and molt one last time. As the last molting is removed the chrysalis is left. This is the moment of metamorphosis. The tissue, limbs and organs of the caterpillar are all going through a change. It moves from being a converter of food to energy to being a reproductive butterfly. This transformation can take anywhere from 10 days to several months, and some species of butterfly will spend the winter in the chrysalis form.
The final stage is that of the adult butterfly. As the butterfly emerges its wings will be soft and folded against its body. It will take a little time for them to extend and harden. If you are using Painted Lady butterflies you will notice red drops coming off of them; it is simply the excess color from the chrysalis stage that will give the wings their brightness. This can take three or four hours to complete; however, you will see movement of the wings soon to get them to dry and fully spread out. Once the adult is able to fly it will be ready for sugar water, or nectar in the wild. It will also be ready to reproduce. If you have a large enough holding area and the right environment you may be able to see the entire life cycle from birth to rebirth of the butterfly. This is much more difficult for other animals.
It may surprise you to discover that a toad is a frog. There are many fun and strange facts available about frogs and toads. In the teacher resource portion of this unit you will find a list of books and websites for you and your students. Although I am sure my student's questions will lead us to compare and contrast not only frogs and toads but also different types of frogs and toads, as well as where they live and all the crazy facts that can be found. I will not be including them in the body of this unit. I encourage you to use the list of resources I have provided for your personal research as well as that of your students.
For this unit I will be focusing on a few main facts. Frogs are an amphibian which means two lives. During their life cycle they go through what is called an incomplete metamorphosis. This means they do not go through a pupal stage during their life cycle. Frogs begin as eggs in the water; however, as adults they can live on land breathing air with lungs. It is believed that there are over 4,000 different types of amphibians. Frogs are cold-blooded; this means that they are the same temperature as the environment they are in. They will seek out shade or water to cool off or the sun to warm up. This also means that more frogs tend to live in warmer climates. However, frogs can be found in every part of the world with the exception of Antarctica. As frogs begin their life in water they will tend to be found near any form of fresh water, but they prefer water that is still such as lakes, ponds and marshes.
We will utilize five main stages in the frog life cycle. First, eggs which are laid in the water by a female frog. The eggs which are covered with a jelly like substance to protect them from predators; this can be called frog spawn or egg masses. These "egg masses" can contain up to 4,000 eggs. After they hatch from the egg the second stage is called a tadpole or polliwog, they remain in the water where they swim, eat and grow. At this stage they very much resemble fish and use gills to breathe and, like fish, a tail to move. The third stage is a tadpole with legs, they will develop legs first (arms will develop later near the end of this third stage). The head will also become more distinct. They are still breathing with gills and remain underwater. The fourth stage is called a froglet. The most drastic change is the addition of lungs and the ability to breathe outside of water. The froglet resembles an adult frog with the exception of a tail and smaller overall size. Finally the fifth stage is the adult frog, where the tail will be absorbed into the body and the frog will now breathe exclusively with lungs. It should be noted that there are always various adaptations to these stages some tadpoles have lungs and need air to breath and some frogs live their entire life under water without the need to go on dry land.
There seem to be two main types on frogs that are easily available for online purchase and classroom use. One is the African Dwarf Frog (also known as the African Water Frog), which lives underwater its entire life. I am interested in utilizing this particular frog to show how adaptations are found in many animals and insects. They do have lungs so they need to surface for air. Their complete metamorphosis can be experienced in 8 weeks. However, they are very small and can be difficult to view. They will live 5 to 18 years and should not be released into the wild. The other popular frog is the Leopard frog which has approximately a 12 to 16 week time span for metamorphosis and a life span of about 5 years. These frogs will need land or a dry area as they near the froglet stage. I should also caution you that frogs will eat tadpoles as well as other frogs. It will be important to take these habits into consideration prior to bringing them into your room.
I have noted a few online purchasing resources in my materials section. From what I can tell both of these frogs are small and it can be difficult to see all the changes during a life cycle. In contrast the bull frog is much larger and the stages of metamorphosis can easily be seen. However, it can take up to 2 years to progress from egg to adult frog. Bullfrog tadpoles are also available online. If they are purchased as tadpoles the expectation is they will take 8 to 12 months to mature depending on your school year it is quite a commitment but could be well worth it for the student's ability to observe the stages. I plan to buy mine before the school year begins in early August so that by June when we are out they should be able to see the most exciting changes if not the whole metamorphosis. It should be noted that the part of the country I live in bull frogs are safe to release into the wild. This is not true of all areas. Please check with your local environment and be sure it is safe to allow any animals you have raise in your room to be released into your local environment.
A chicken is a bird. Birds are distinct for being the only animals with feathers. Although not all birds fly, they do all have wings. Bird eggs come in a variety of colors and sizes as well. A study of bird eggs alone can be fascinating from the tiny egg of a humming bird that is about the size of a jellybean to the large melon-sized egg of an ostrich. For this unit we will focus on three main stages of the chicken's life cycle. However, we will utilize videos and pictures to help students see the development that occurs inside of the egg. Although we will not be experimenting with the fertilized eggs we will do a few experiments with unfertilized eggs as well. I have a list of some experiments in the activities section and some resources noted later as well. This will again bring the inquiry into our activities and allow students to continue to further develop their scientific thinking and the use of the scientific method.
A female chicken called a hen will lay eggs in a nest. The eggs that have been fertilized by a male chicken called a rooster will contain an embryo. Eggs that have not been fertilized will not contain an embryo; these are what we eat for breakfast. The fertilized egg contains a yolk, amniotic fluid (egg white) and a blood spot. The blood spot is small and is where the embryo will develop. It takes about 21 days for the embryo to grow into a chick. During the 48 hours prior to hatching the yolk will be pulled into the abdomen of the chick and used as food for the first few days after hatching from the egg. The hard outer shell of the egg protects the growing chick. As the chick develops they have a special growth on their beak called an egg tooth. They will use this tooth to break open the egg when it is time to hatch. It can take up to a full day for a chick to fully hatch from its egg.
The second stage is the chick. Once they have escaped the egg, chickens will be wet and scrawny. The egg tooth they developed will soon disappear. As they dry and their down feathers fluff out they will start to look more like the cute little chicks we all know and love. Chicks will be able to walk almost from the moment they fight their way out of the egg. They will eat seeds, bugs and worms as well as the food that you provide. We will take this time to compare and contrast baby birds, baby mammals and even baby amphibians. How they have developed so far, what they need to continue to grow and develop and how they will continue to change in appearance. After about 4 weeks new feathers will have grown in, and the down feathers will have all fallen out. Chicks will also begin to develop a comb on the top of their head and a wattle under their beak. It is also good to note that from the time a chick emerges from its egg it resembles its parent. As they grow they will continue to develop traits found in their parents such as size and feather color.
The third stage in a chicken's life cycle is adulthood. It takes a chicken about six months to become an adult. The female hen will begin to lay eggs at or near this time. Most hens can lay two eggs a day through the spring and summer this will slow over the fall and they may not lie any over the winter. However, some chickens have been bred to produce a larger amount of eggs. Eggs come in a variety of colors from white, brown, green, blue and even some are speckled. The size can vary as well based on the breed of chicken. Chickens can live up to 12 years depending on the breed. Chickens don't chew their food nor do they even have teeth. They will swallow their food whole, where it goes into a gizzard that holds tiny stones and is then ground up before it makes its way to the stomach. If you have chicks in your room you will need to be sure and provide these "stones" that can be purchased along with the food.
I will get my eggs from Oklahoma State University's local agricultural site. They provide the eggs and incubator along with assistance on care, feeding and raising. I will then be taking the chickens home with me and will then utilize them for their egg production for later school years and personal use. I would encourage you to contact your local agricultural department or even Four H Club to see what resources they may have valuable for use in schools. If you are not able to utilize a local organization to acquire eggs and borrow an incubator it can be quite expensive. However, you can order chicks online or get them from a local farm. It is not quite as exciting as seeing them hatch form an egg but the growth and development is also exciting to watch and can be documented by students.
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