Living? Nonliving? Dormant? Dead? Even though teaching living vs. nonliving seems very elementary, you'd be surprised by how often high school students get confused when you throw examples at them. It makes me think of this 90's "J-E-L-L-O it's alive!" commercial:
But in all seriousness....
Teaching characteristics of life is a great way to start off the year in biology. I like teaching it week 1 because it's more fun than the scientific method (which they should know by now anyway) and a great introduction to biology- the study of living things. Here are a few resources you can add to your teacher toolkit for your life unit:
This is one lab that you don't want to miss! It's easy, the materials are inexpensive (you probably already have them at home), and it ties together multiple concepts. Winner!
In this lab, students will analyze a pedigree of a fictitious family. In the introduction, students read that "Jon and Sue Smith" were in a car accident and need a blood transfusion. The hospital asks family members to donate, but students will need to figure out which family members are able to successfully donate. To complete this lab, students will need to understand blood types, punnett squares, and pedigrees. Its a great end-of-the-unit lab when you are finished with genetics.
One piece of feedback I have gotten from my TpT store is that this lab can take a while to set up. I'm here to give you some tips to save you set up AND clean up time.
This lab is one of my top sellers in my Teachers Pay Teachers store. It is easy to set up and doesn't require a lot of materials. However, I frequently get questions about the lab so I'm hoping this blog post will be useful to those teachers out there who about to set up this lab.
In this lab, students will be testing whether or not aquatic plants do photosynthesis in the dark or light, and also testing if they do cellular respiration during the dark or light. The plant I usually use for this experiment is called elodea, which is available at any local pet store in the fish area. One nugget of information you will need to know- pet stores call it anacharis, not elodea. It is usually sold in bunches of 4-5 stems for a few bucks. Two big bunches should get you through the day. If they don't have elodea, any other aquatic fish tank plant will work fine, but make sure it is a tall skinny plant that will fit down into your test tubes.
One reason this lab is great is because it can be used in multiple places in your curriculum:
~ Cells unit: When you are teaching cells, chances are you will be talking about chloroplasts and mitochondria. Along with these organelles you will be discussing photosynthesis and cellular respiration. This lab fits in great because it shows that plants not only do photosynthesis, but cellular respiration as well.
~ Ecology unit: During my ecology unit, we cover the 3 major biogeochemical cycles (water, carbon, and nitrogen). What better way to talk about the carbon cycle than to demonstrate the relationship between plants, animals, and gas exchange?
A little background....
This lab uses the chemical bromothymol blue. This chemical is used as a pH indicator. When the pH is above a 7 (basic) it is blue, but when the pH drops below 7 (acidic) it starts to turn yellow.
Image below is courtesy PureySmart on Wikimedia Commons.
Before beginning the lab, I like to demonstrate to the students how bromothymol blue works. I get 2 erlenmeyer flasks (beakers will work just fine too) and fill them 3/4 of the way full with water. Add enough bromothymol blue for the water to be visibly blue. (In a beaker of 200mL of water, I add about 4mL of bromothymol blue). Call up a student, and have them blow through a straw into the beaker. As they blow (it will take 3-4 big breaths) the water will slowly change from blue to yellow. This is because when the carbon dioxide in our breath reacts with the water it forms carbonic acid, lowering the pH.
Inquiry, Inquiry, Inquiry
When I do this lab, I do not tell students how to set up the experiment. I split the class into lab groups, and assign each group one of the following questions:
1. Do plants to photosynthesis in the dark?
2. Do plants do photosynthesis in the light?
3. Do plants do cellular respiration in the dark?
4. Do plants do cellular respiration in the light?
Obviously the group that gets assigned "do plants do photosynthesis in the light" will know the answer, but they will still have to set up a controlled experiment that can demonstrate it. I give each group a big white board and have them set it up like the image below. They will have to fill it out based on the specific question they are assigned. If you don't have whiteboards, butcher paper works great too. Students will know what materials they have to work with because they are listed on their lab worksheet (available in my TpT store).
As we walk around the room and discuss experimental design, students will begin to see that each group will set up their test tubes the same way, the only difference being if their tubes get left in the light or wrapped in foil and put in the dark for 24 hours.
Two notes: I get asked how much bromothymol blue to add to the test tubes. I have each group add 1mL to each tube. If you would like to add more or less that is fine, as they add the same amount to each test tube for consistency. Also- make sure to fill the test tubes to the top and cap them tightly, or use parafilm to cover the tops. We want the gas to stay in the water, not escape.
When students come in the following day they will pick up their test tube rack and fill out their data tables on what happened. They will see that the elodea did photosynthesis in the light, and cellular respiration in the dark.** (see note below)
**One thing you will have to discuss with your students: Plants are doing cellular respiration in the day time as well, but since photosynthesis is also occurring the indicator stayed blue.
A great extension activity is to add aquatic animals to this experiment and see how the added respiration affects the color change. If you can get your hands on some small snails, they will fit great into the test tubes. I had trouble finding snails in Arizona, so I went to my local pet store and picked up two feeder goldfish. I filled up two large erlenmeyer flasks with water and bromothymol blue, and turned one yellow. I added elodea and a goldfish to each flask. Next, I asked my students what will happen when we leave these in the light for 24 hours. The next day we came in and saw both flasks were a shade of bluish green (somewhere in the middle of where the two flasks began). If you don't add a ton of bromothymol blue, and only leave the fish in for 24 hours the fish will not be harmed.
Hopefully you are ready to start this experiment! If you have any questions, drop them in the comments below!
Need a great inquiry lab? This soda lab is FUN! And I know what you are thinking.... "what a mess it must be!" But I've done this lab multiple times, and never had a spill. Students will get 3 types of soda, and will measure which brand has the greatest amount of carbonation. The best part of this activity is there are 4 different versions included- you can choose which you think is best for your students.
~ EASY~ Great for lower grade levels. Students pour the soda into a cup, and measure the amount of time it continues to bubble.
~ MEDIUM~ (Pictured bottom left) Students cover the top of the bottle with a balloon. After shaking the balloon covered bottle, students will measure the diameter of the balloon with a string.
~ HARD~ (Pictured bottom right) Students will measure the amount of carbonation by putting a tube into the bottle, and catching the gas that escapes into a graduated cylinder. This is the most accurate way to measure the carbonation. I used a tube that was from a fish tank bubbler.
~ EXPERT~ Students will come up with their own experimental design (They may come up with one of the other three ideas already discussed). Great for inquiry, collaboration, and practice writing procedures.
To save money on this lab I buy the smaller bottles of soda, and usually snag them when they are on sale, even if I'm not doing this experiment right away. I love that this lab is a great time to review the scientific method, experimental design, and discuss variables such as temperature, rate of shaking, and other factors that could impact the results. This is a great lab for days before holidays or testing days when the kids are antsy. They will have a blast! Interested? Check it out in my TpT store HERE!
pH.... one of those chemistry topics that us biology teachers get to teach. In biology I don't make my students calculate pH and pOH values, but they need to understand what pH is and why maintaining a healthy pH in your body is so important. You may love biochemistry, or you may hate it, but either way there are plenty of resources to make teaching pH easy!
One of the first things I have my students do is make a pH foldable. As we go through the lesson, they take notes on acids and bases, and label the pH scale at the bottom. Foldables are really easy to have students make on their own, but if you are interested in a template, click here.
After students learn what pH is, I have them complete a pH lab. The lab available in my TpT store is editable, so you can use whatever liquids you have on hand. I try and find a couple acids, a couple bases, and some neutrals (especially water!). A few hints to make your lab go more smoothly: First, don't let the students grab the roll of pH paper themselves. Save yourself some money by making your pH and litmus paper go further by pre-cutting them. I cut the litmus paper in half and cut the pH paper into small strips. Students can use tweezers to dip them into the liquids, so small pieces work great. By cutting them in half I could get through the whole day with one vial of red and one vial of blue. Also, put your pH color keys in a ziplock baggie. Students always hold the wet pH paper up to it for comparison, and if it is in a baggie it won't get ruined.
Since I teach pH right before I dive into cells, this is a great time to talk about enzymes and denaturation. When the pH of our body changes, these enzymes can unfold, or denature. Once enzymes change shape, they no longer function. Enzymes are very specific, so enzymes that are in your stomach will work best at an acidic pH, and enzymes in your bloodstream will work best around a neutral pH. If you have some extra pH paper it is fun for the kids to put a piece on their tongue and measure the pH of their saliva. We talk about how there are enzymes in their saliva that start the digestion process.
Another good topic to talk about is neutralization in the body. I usually start by telling students if I drink orange juice on an empty stomach, I will inevitably get a stomach ache. Why? Students usually recognize that orange juice is an acid and the acid is causing the belly ache. Next, I ask them what do they do when they have a stomach ache? We talk about Tums and Pepto Bismol, and how the alkaline medicine neutralizes the acid in my stomach. It is also fun to talk about bee stings vs. wasp stings. Bee venom is acidic, so putting baking soda on it will help take the pain away. On the other hand, wasp stings are alkaline, so baking soda won't help at all. Instead, putting vinegar or another weak acid should help with the pain. Students are always find these topics engaging and try and come up with other situations where they have needed to neutralize their body pH.
Is food chains up next in your curriculum? Most students learn food chains in the elementary grades, so how do you make it interesting and rigorous at the secondary level? Here are some great options:
This website is a great review of food chains. It is pretty basic, but if you have an interactive whiteboard it’s a quick and easy way to have students come up and show you what they already know. While the order of the animals is pretty obvious, students will need to know where to put them based on the directions of the arrows. I also like that the food chains include the sun, so students recognize that the sun is the source of the energy.
This is a great youtube video on food chains. It shows a food chain in the everglades, and reviews important vocabulary like herbivore, carnivore, producer, and consumer.
This skull lab is always a hit! I take out the skulls before introducing vocabulary words like herbivore, carnivore, nocturnal, or diurnal. Students will analyze the skulls and make inferences about how the animal lived. They have a really fun time trying to figure out which animals they are too! Don't have skulls handy? Don't worry! I have a great paper version of this lab in my teachers pay teachers store. Check it out here.
Last but not least is a lesson that demonstrates why it is important that trophic levels remain in balance. In this activity, students play the role of grass (producer), rabbit (primary consumer), or a coyote (secondary consumer). Throughout the 5 rounds, students will go around the room and pair up with another student. If they find a prey they get to eat it. If they find another organism of the same species, they reproduce. If they don't eat or get eaten that round, they are out. Students will quickly learn that there needs to be few secondary consumers and a lot of producers for a community to be sustainable. Check it out in my teachers pay teachers store here.
When you make ecology hands on and interactive, students will have a blast. What other activities do you do with your students when teaching food chains? Leave ideas in the comments below!
It's the beginning of the year, and chances are you are starting off teaching or reviewing the scientific method. If you've looked around on the internet for scientific method labs, you will notice that the majority are not biology related. Don't get me wrong- building paper airplanes, measuring bubbles, and seeing how many water drops can fit on the surface of a penny are fun labs, but not directly related to biology. In my class I want students to understand from the get-go that we are learning about living things, so I want my first lab to reflect that. Here are a few labs that can start your year off right:
1. Pulse Lab- This is a great lab because there are almost no supplies required other than a stopwatch. In this lab students measure their resting pulse, and compare it to their pulse standing up and holding their breath. It is a great way for students to practice writing hypotheses, and identifying independent and dependent variables. Before beginning the lab I start with a class discussion about what your pulse is, why blood needs to be pumped through the body, and where blood cells are made.
2. Firework Milk Lab- I have seen this lab done at ALL ages. Even preschool teachers love this lab. But the beauty of this lab is that high school students still love it, and they can finally start to understand the concept behind the fun swirling colors. In this lab students pour milk into a petri dish, add some food coloring, and put a drop of soap in the middle of the dish. Once the soap enters the dish the food coloring starts swirling and creating "fireworks." The reason the soap begins to mix the food coloring around is because of the chemical structure of the soap. The soap molecule has a polar portion that likes to mix with water, and a nonpolar portion that doesn't like to be around water. The soap molecules react with the fat molecules in the milk and start swirling around, which is visible from the movement of the food coloring. The fattier the milk, the better a reaction you will get. It is fun to have students test whole milk and skim milk and compare the results.
3. Testing the 5 Second Rule- This is my favorite lab to begin the year with, but it requires a little prep work. While you can order sterile agar plates from any science supply site, it is much cheaper to pour your own. If you haven't poured your own plates before, there are a ton of youtube tutorials available to walk you through it. In this lab students get to design their own experiment that would test whether or not food is really safe to eat after being on the ground for 5 seconds. When you purchase this lesson from my TpT store you will get two versions. In the high school version students design their own experiment, write their own procedures, and choose their own independent variable (food type, surface that they drop the food on, etc.) In the middle school version the procedures are given and it walks the students through the lab step by step. If you have an incubator the plates can be ready in 1 day, if not then let the plates sit over the weekend. Students will love seeing how much bacteria is on their food! You can even take it a step further and have students try and kill the bacteria with different cleansers (soap, bleach, 409, etc.) and see which is the most effective.
What other scientific method experiments do you love? Leave them in the comments below!
It's what most people think of when they think back to their high school biology classroom.... dead animals in jars. Why are they even there? How can you use them in your classroom? And God forbid, what do I do if one of the jars breaks?
I like to incorporate the preserved specimens into my taxonomy and classification unit. After I teach my students about the Linnaean system of classification, I ask students to classify the specimens I have.
Here's how it works:
1. Set up your tables into groups. I put 3-4 specimens per group, depending on how many specimens are available.
2. As soon as students walk in the room, ask them to not pick up the jars. (You will have to repeat this!) Once everyone is settled we talk about handling formaldehyde (once you tell them it can cause cancer they are usually pretty cautious). I let students slide the jars around the table but not pick them up. This majorly helps with safety issues.
3. Each group gets a classification packet. Their task is to find the organisms in the packet that are sitting in front of them. Once found, they need to write down as many classification levels as they can. The biggest thing to tell your students is to work backwards- instead of finding the kingdom first, they will find the animal under phylum or class, and then work backwards in the packet until they get back to the Kingdom. Don't worry if you are confused, samples are provided in your purchase!
4. Depending on the length of your classes and how many days you want this lab to last, you can have students rotate around the room. I've found that students can usually get through 4-5 specimens in a 50 minute class period.
Don't have any specimens lying around? Don't worry, a paper lab has been provided for you as well. Check it out in my Teachers Pay Teachers store!
Natural selection is one of my favorite topics to teach. Students enter the classroom with prior misconceptions and it's fun to have students figure out what natural selection and evolution really mean. Here is a list of my favorite natural selection and evolution activities:
1. Battle of the Beaks- This lab is always a hit! Students get to simulate Darwin's finches by having different "beaks" (tweezers, clothespins, etc) and feeding on different foods. Check it out here FREE in my TpT store!
2. Rock Pocket Mouse- In this activity students examine how fur color in pocket mice determines their fitness. Students learn that mutations aren't good or bad, but instead are beneficial or harmful based on their environment. Check it out here for free on biointeractive's website.
3. Who Wants To Live A Million Years?- In this online game, students get to choose traits of a fictional species and see if their species can survive a million years.
4. Analyzing Darwin's Finches- This activity looks at the research of Peter and Rosemary Grant. This couple studied Darwin's finches on the Galapagos Islands and saw evolution occur twice within a short number of years. This activity incorporates graphing skills which is always great to throw in! Check it out here.
5. Speciation Video- When you talk about how all of today's species evolved from a common ancestor, naturally many questions will arise. How do new species form? I love how clearly this video explains the process of speciation.
I also have some evolution writing prompts in my store too! Check out my blog post on how I use writing prompts in my classroom!
IT'S SUMMER! The time we get to sleep in and relax (a little....) As a science teacher I've had multiple friends ask me the same question: "What science activities can I do with my kids over the summer?" I remember growing up over the summer my Mom making rock candy with us (which never seemed to work out very well, but I digress). I've complied a list of 5 activities that are easy to do and you probably already have the materials at your house.
1. Solar Cookers: Since I live in Arizona, solar cookers are a must. All you need is a shoe box and a little tin foil, although they can get fancy depending on what you have lying around. Put inside one of your kids favorite snacks- hot dogs, smores, or even cheese quesadillas. Have a little contest and see who can build the hottest solar cooker.
2. Firework Milk Lab: This lab is great because you can do it with almost any age. Little kids love it, and even my high school students enjoy watching the milk swirl. All you need is milk, food coloring, and some soap. See it in action here.
3. Density Column Lab: Grab some liquids laying around in your kitchen and get pouring! Slowly pour various liquids into a clear glass and watch the layers form based on the densities of the liquids. It's best to add a little food coloring to see the layers more clearly. Some favorite liquids are vegetable oil, water, honey, and rubbing alcohol. See it in action here.
4. Sink or Float Lab: Grab a big tub of water (an aquarium works great but the bathtub will do) and objects that you can put in. Ask your kiddo before dropping it in- will it sink or will it float? Some objects will surprise you. For example, a grape will sink, but a banana will float. A can of coke will sink but diet coke will float. See the soda cans in action here.
5. Balloon Rockets: have your kids explore Newton's 3rd law of motion with this fun activity. All you need is a piece of string, a balloon, a straw, and some tape. Run your string across the room and tie one end of the string to something heavy (like a chair). Next, thread the other end of the string through the straw. Blow up a balloon and tape it onto the straw so the opening of the balloon is facing you. As you let go of the balloon, you will see it race down the string. Have your kids measure how many breaths of air it takes to make the balloon go across the entire room. See it in action here.
What other science related summer activities do you enjoy? Leave them in the comments!
Becca of Science Rocks
Hi, I'm Becca! I've been teaching science for 10 years at both the middle and high school levels.