Epigenetics is a fascinating field of science. If you aren't familiar with it, the epigenome is the study of how your behaviors and environment impact gene expression. I pose the question to my students- if an identical twin gets cancer, does that mean the other twin will automatically get cancer? Students will generally say no. If that's the case, then what controls gene expression?
The cell membrane, which surrounds the cell, is covered in receptors. They act as antennae so cells can send signals and communicate with one another. Cells respond to environmental signals all the time- examples could include releasing insulin when blood sugar rises, or dividing when cells die and numbers drop. (Because of this, it could be argued that the cell membrane is the control center of the cell, not the nucleus. While the nucleus holds the genetic information that is needed to make proteins, it is the membrane that acts as the guy in charge by receiving signals on how to proceed).
So essentially you could have a gene for something, but unless the cell receives a signal to turn the gene on, (in other words- copy it and turn it into a protein), the gene will remain off. You could very easily have a cancer gene but live your life cancer free if that gene remains turned off. The decisions you make in your life, which influence cellular environmental factors, play a large role in gene expression. Here are some activities you could do with your students to teach them about epigenetics:
1. NASA Twin Study: You may have heard about Mark and Scott Kelly, who are identical twins and NASA astronauts. Both twins spent time on the International Space Station, but Scott spent a lot more time- a whole year. NASA compared Mark's DNA with Scott's DNA after he returned to Earth. This was a unique opportunity to learn the impact of space and zero gravity on our DNA and gene expression. You can learn more about the study here.
2. Case Study: University of Buffalo has a TON of case studies I encourage you to check out. (They are all free, but if you want the answer key there is a yearly subscription fee). One study is called "Identical twins, identical fates?" that explores epigenetics.
3. Learn Genetics: University of Utah's learn genetics website is an amazing resource for all things genetics. They have a section just on epigenetics. The "epigenome at a glance" is a great introductory video.
4. Partner Activity: This lesson and activity introduces students to epigenetics. Students will read about the agouti mice study (super fascinating!) and then complete a "twin" activity with a partner.
5. Bacteria Culture Lab: If you have time to order supplies, check out this lab from Flinn Scientific. Students will see the effect of temperature on bacteria growth and phenotype (it will change color). You will need to prepare agar slides and have access to an incubator.
6. Podcast: Big Biology podcast has an episode called "genes don't do crap" that features Dr. Massimo Pigliucci, an evolutionary biologist and philosopher. The episode is 16 minutes long, and I would recommend this for honors or AP students.
7. Queen Bee: Bees are a great example of epigenetics in action. The bees in an entire hive all have the exact same DNA- the drones, worker bees, and Queen are all clones. If they are all clones, then why do they look different and have different jobs? The answer is epigenetics and "royal jelly". Check out this video you can show students that explains more detail.
8. Documentary: The NOVA documentary "Ghost in your genes" investigates how our "secondary genome" helps determine our biological fates.
9. Epigenetics Game: This game has 4 levels students can work through all dealing with epigenetics.
10. Histone Model: In this download from University of Utah, you can have students build a paper histone model.
Do your students truly understand protein synthesis? Not just knowing how to convert DNA to mRNA to amino acids, but TRULY understand how and why the process works? I struggled with this for a while. My students were great with A's, T's, C's, and G's (and U!) but couldn't explain the bigger picture.
I wanted students to be able to answer this question: If every cell in the body has the exact same DNA, then why do cells look different and do different jobs? Why are muscle cells long and stretchy while nerve cells are web-like, yet they have the same set of directions inside?
To answer this question students needed to understand that genes can be turned on an off. Even though every cell in the body has the same DNA, cell types only read the genes that apply to them. Eye cells only read and use eye genes, skin cells only read and use skin genes, etc. So how do specialized cells know which genes apply to them?
I created an activity that likens the genome to the blueprint of a house. A house blueprint includes all the information needed to build the house- the electrical, the plumbing, the framing, it's all there. When the electrician shows up to install the wiring and outlets, he only needs the information on the blueprint that applies to him. The same goes for cells.
In this activity, I put students in groups of 4. Each student was assigned a different job- a plumber, an electrician, a framer, and a roofer. On each job card is a promoter sequence. (Promoter sequences are used by transcription enzymes to know where to begin transcribing the gene).
Each student will scan through the DNA looking for their specific promoter sequence. Once they find it, they begin the transcription and translation process until they reach a stop codon.
Once each student has their genes transcribed they go to the house blueprint and look up which trait the house will have based on the amino acid sequence (see image below). If you have honors or pre-AP students you can have them complete all 4 jobs, or 8 genes total instead of 2.
I hope you check out this activity and your students can really understand the process of protein synthesis. If you would like to purchase this activity, you can find it HERE in my TpT store.
Looking for some new ideas and activities to teach cladograms and phylogenetic trees? Check out this list below of fun activities and interactive websites.
Cladogram Construction: This free activity from Carolina Biological is nice and simple- a great way to introduce cladograms to your students. It has students construct a cladogram and then make inferences about related animals based on derived characteristics.
Build an Insect Cladogram: In this activity, students are given insect cards and have to create their own cladogram based on shared traits. At the end of the activity they fill out a CER form explaining which insects share the most traits.
Teach Genetics from University of Utah has a bunch of awesome resources. Students begin by sorting seeds using their own system of classification, and then move on to real case studies of common ancestry. Not one you want to miss!
The Great Clade Race: In this activity, students are given "runner" cards and choose different paths to complete the race. You can read more about the activity here and download the cards here.
Candy Cladograms: Get your students engaged with any activity by adding candy as an incentive. In this activity, students are given a bag of assorted candy and have to create a cladogram based on shared traits.
Build A Tree: In this fun game, students work through different levels building phylogenetic trees and dragging common traits onto the correct part of the tree. Make it a classroom competition!
What did T-Rex taste like? This interactive website from UC Berkley walks students through phylogenetic trees and includes handouts and even assessments in the teacher's guide section.
PBS Learning Media has a series of 6 interactive missions students can complete all related to evolution. Mission 5 deals with phylogenetic trees to uncover the sources and treatments for diseases and parasites.
Dogs Decoded: In this activity from Biology Corner, students analyze characteristics shared between dogs, wolves, and coyotes and determine which is most closely related.
Evolving Trees: In this activity from Cornell Institute, students are given a cladogram to work backwards and analyze, and then create their own cladogram with a hypothetical fly species.
PhyloPic: Want to build your own cladograms and looking for images to use? Check out PhyloPic. This site has silhouette images that you can download and easily use.
I hope you found an activity or two your students will enjoy!
If you've scoured the internet looking for fun Karyotype activities like I have, you know they are few and far between. Most activities involve students cutting out 23 chromosomes, finding the homologous pair on a worksheet, and gluing them together. This activity ends with paper scraps everywhere, missing chromosomes, and frustrated students.
My goal was to create a station activity where students could rotate around the room and analyze and manipulate different karyotypes. I also found some great resources from Ward's Science that I used to supplement the activity. Student groups had 5 minutes at each station to complete a karyotype related task. Here are some station activity ideas:
On U of A's website, there is a virtual karyotype activity with 3 patients. Students need to click on each patient, fill in the missing homologous chromosome, and give a diagnosis for each patient. You can check out the website by clicking here.
Karyotype Virtual Lab
In this virtual lab from University of Utah, students pair up the chromosomes on the left with their homologous pair on the right. It's a bit harder than the U of A one, but there is a hints option if students get stuck.
At this station, students will watch a Youtube video and answer a few questions. This video reviews genes, chromosomes, and karyotypes.
Human Genome Analysis
When the human genome project was completed, the genes on each chromosome were mapped out and they came out with these nifty (and free!) science posters. On their website, you can click on any chromosome, print out the pdf, and have students observe what traits are found on each chromosome. I printed out a few and had students look for traits they have or run in their family.
I ordered giant magnetic pictures of human chromosomes from Ward's Science (you can purchase them here). At this station, students came up to the front whiteboard where I had 23 of the chromosomes lined up. Their task was to arrange the homologous chromosomes and decide if it is a male or female, and healthy or abnormal.
I love these magnets because they can be used throughout the whole unit, not just for this lesson- makes them worth every penny! You can use them when discussing cell division as well. They are large, easy to see, and students love coming up to play with them at the end of class.
Microscope Slide Observations
At this station, students observed a human karyotype smear under the microscope and made observations. If you don't already have karyotype slides, you can purchase them from Ward's Science. Students will be surprised how small the chromosomes are! (the picture shown is on 100x magnification). They will quickly see that in real life, pairing up homologous chromosomes and looking for abnormalities is not nearly as easy as it looks on the virtual labs.
If you'd like to check out the full activity that includes 8 stations and student lab write-up, you can download it here. I've also included multiple options for different stations in case you don't have access to the slides or magnetic chromosomes.
*If you are already familiar with how CRISPR works to make GMOs and just want the teaching resources, hop down below the Youtube video*
Some people are terrified of the phrase "Genetically modified organism," yet they are literally everywhere. Roughly 75% of the foods in grocery stores have been genetically modified in some way. While creating a GMO used to be a long time consuming process, the development of CRISPR technology has made the process much faster and cheaper. As CRISPR technology becomes more refined, GMOs are going to become more common, not less, and we need to teach students about them.
How CRISPR Works
I recently was able to attend a seminar talk at Arizona State University by Jennifer Doudna, who helped develop CRISPR technology. If you aren't familiar with how CRISPR works, here's the gist:
Alright, ready for some teaching resources?!
1. The website Unlocking Life's Code has a good overview of CRISPR and links to additional resources. You can check it out HERE.
2. This interactive from PBS shows students how GMOs can be made (this is not via CRISPR). I like that it is simple and easy to use. You can view the interactive HERE. HHMI has an interactive site showing how CRISPR works you can view HERE.
3. This New York Times article has a student reading and questions, along with a ton of helpful links to get you started with GMOs. You can find it here.
4. Want to try some GMO speed dating with your students? In this activity, students are given an organism card (they are either a donor or a recipient) and go on "speed dates" with other organisms and determine if they have any genes that would be beneficial in sharing. You can find the lesson HERE. Note: Having done this activity with students, I would recommend it for honors/AP students.
5. If you haven't seen the University of Buffalo's case studies, you need to check them out. They have a TON of great resources for free (you can pay an annual fee for the answer keys, but usually aren't necessary). They have a bunch of case studies relating to GMOs you can view HERE. I have done the golden rice debate with my students and it always works well.
6. A fun activity you can do is to bring in a bunch of foods from home and have students scan the barcodes with the "Now Find Organic and Non-GMO" app (available for free in the app store). I've found that not every food I scanned is in the app, so be sure to try it at home first.
7. I had my students read this article from Nature and we held a Socratic seminar. The article examines if we should be able to edit our children's genes. It was interesting to hear my student's viewpoints on the topic (the majority were firmly against any sort of gametic gene editing).
8. The University of Washington has a lesson on GM salmon that includes 4 different stakeholders for them to read about. You can check out the lesson HERE.
9. Since I teach a PBL style course, I came up with a Shark Tank project where students had to design a GMO and pitch it to a bunch of sharks (the panel was made of teachers and college professors). This lesson in my TpT store has an outline of the worksheets and activities I used (note: it is not a print and go daily unit, but a guide for the project).
10. If you have time to show a documentary, Food Evolution narrated by Neil deGrasse Tyson is a great option that explores GM foods. While every documentary has a little bias, this is much less bias than Food Inc. and a better option. You can view the trailer below:
11. BioRad has a free cut and paste paper activity where students simulate the CRISPR-Cas9 process. It can be found HERE.
As I find more resources I will add them to the list. If you have any additional favorites, leave them in the comments!
Protein Synthesis is actually a fun concept for me to teach. For me, there are 2 barriers you need to cross in order for students to learn protein synthesis:
1. Learning about the steps of transcription and translation (the easier part)
2. Understanding how DNA translates into gene expression (the harder part)
Most of my students do really well with step 1. They can learn the A's, T's, C's, G's, and U's and where the processes are taking place. But at the end of those lessons, if you ask your students how they have brown eyes, can they answer? It can be difficult to understand how genotypes code for phenotypes. I've put together a list of resources to help walk you and your students through the process.
TEACHING TRANSCRIPTION AND TRANSLATION (The easier part)
1. USE INTERACTIVES.
Check out this interactive website where you can go through the process of transcription and translation up on the board with your students. This is a fun way to wrap up your lesson, or use as a reinforcement activity to follow up.
2. USE PUZZLES
Once you've taught the process, you need to have students practice, practice, practice before the test. It's not an easy topic, and they need to have multiple opportunities to review the vocabulary. Check out this puzzle in my TpT store that I use as a review activity.
3. USE VIDEOS
Seeing the process of protein synthesis in real time helps students see the bigger picture much better instead of focusing on the nitty gritty details. Check out these videos from biointeractive of transcription and translation occurring in real time.
TEACHING GENE EXPRESSION (The harder part)
4. USE EXAMPLES
Providing your students with many examples of how DNA --> RNA --> PROTEIN work is critical in helping them understand the complete process. Give them examples from their own body (the gene for melanin showing up as a pigment in their skin and eyes). CLICK HERE to see an example (with video) of a protein that makes fireflies glow.
5. USE ANALOGIES
Do your students understand why all your cells have the same DNA, but they all look different and do different jobs? I created this activity to help students understand how cells have certain genes turned on and certain genes turned off. In this activity the genome is likened to the blueprint of a house. Each student is given a job (plumber, electrician, roofer, or framing) and has to transcribe and translate only the genes that pertain to their jobs. It really helps students understand that cells do not use most of the genome, only genes that apply to them. CLICK HERE to check it out.
If you are interested in a bundle where you can find a lesson, puzzles, review worksheets, close readings, quizzes and more, check out this protein synthesis bundle! It literally has everything you need to get through this unit.
Have any other fun videos, websites, or tips for teaching protein synthesis? Share them in the comments!
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One comment I frequently hear from biology teachers is "My students keep mixing up mitosis and meiosis." I had this problem for many years (the first 5 years of teaching to be exact). During my cells unit I would teach both mitosis and meiosis. I would begin by teaching them both separately, and then had worksheets and activities that compared the two. But when I would give the unit test, it was clear the students still confused the two. I needed to do something differently.
After teaching middle school for 5 years, I switched to a high school near my house. When we got to the cells unit one of my colleagues suggested only teaching mitosis, and waiting to teach meiosis until we got to the genetics unit. Light bulbs kept going off in my head. The more I thought about it, the more sense it made.
So I tried it. At the end of my cells unit (after teaching organelles, membranes, and cellular energy) I would teach mitosis. When I would test them just on mitosis they would score well, because they didn't have both processes in their head to get confused. Then, after Christmas break when we got to genetics, I would teach meiosis. It made so much sense because:
By the time I quizzed the students on meiosis they were experts on cell division. If your school gives you some freedom with the order of your curriculum, try teaching it this way! You won't regret it.
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BONUS! If you want a fun way to make sure students understand the differences between mitosis and meiosis, try this FREE bingo game in my TpT store! Bingo is a great way to review scientific vocabulary. In this game you will call out the definitions and students will cover up the words on their bingo cards. You can download this product free in my TpT store HERE. Enjoy!
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.