Quick & easy – no fuss – no mess – way to prepare cabbage juice:
- Chop up half of a purple cabbage
- Add to a coffee pot
- Fill with very hot water from sink or water cooler
- Let it sit for at least 20 minutes
- Pour into flasks, beakers, or plastic cups
- Add a pipette or spoon to containers
You can add more hot water during the day as you use it, refrigerate leftovers if using next day.
Here is the link to my Cabbage Juice Lab: https://middleschoolscience.com/2016/02/28/cabbage-juice-lab-ph-indicator/
Intro to Meiosis with a comparison to Mitosis
Amoeba Sisters Videos:
This is a fun and creative activity to tie all of the following concepts together into one lesson: DNA sequencing & transcription, mRNA translation, amino acid codons & proteins, genotype, phenotype, recessive & dominant alleles & traits.
Students will help solve a crime based on DNA evidence left on a lollipop at the crime scene. There are 3 versions of the same scenario that will identify 3 different criminals so you can use them for 3 classes – this avoids having the kids tell the next class who the suspect is ;). Each student will receive one of the 4 DNA samples – you can have students work individually, or have a group of students work on suspect 1, another on suspect 2, etc. (Sorry – I do not have an answer key to post)
Directions: Worksheets: DNA-RNA-Crime-Snorks-2018 & Amino Acid Codon Wheel, & additional resource: 20 Amino Acids
- Step 1 – students will transcribe the DNA sequences into mRNA sequences
- Step 2 – using the Amino Acid codon wheel, they will determine the amino acid for each codon
- Step 3 – using the chart, they will find protein using the sequence of amino acids
- Step 4 – using the proteins, they will determine the phenotype
- Step 5 – using the phenotypes, they will determine the genotype(s)
- Step 6 – is their suspect the criminal?
- Step 7 – they will draw a mug shot of their suspect using the phenotypes they decoded
This lesson was modified from the one found on Biology Corner: https://www.biologycorner.com/worksheets/DNA_snorks.html
- Students will practice their measurement skills using a graduated cylinder to determine volume and a triple beam balance to determine mass.
- Students will determine the density of water by completing 10 trails and finding an average.
I use this lab to tie their measuring skills together and introduce the concept of density. We then do further explorations of density and practice using the formula.
This lab is a modified version of the lab posted at Middle School Chemistry – for further details about the lesson, please click on this link.
- Introduce how to read a graduated cylinder using the meniscus.
- Review how to determine the increments for each graduated cylinder.
Materials and Set Up – this was so easy and inexpensive to do and had the same effect as using dialysis tubing. Great demo/lab as part of our unit on osmosis and diffusion!
For every two students:
- handout from Biology Corner
- large beaker
- inexpensive sandwich bag – non sealing (I used Wegmans 150 ct)
- 1 tbsp corn starch
- 50 mL water
- rubber band
- clothes pin
- graduated cylinder
- 100 mL Iodine dilution
- 20 ml Iodine added to 500 mL of water
- measure out 100 mL of diluted iodine for each group
- Place one bag over each beaker
- Add 1 tbsp of cornstarch to each bag
- Add 50 mL of water to each bag
- Check for leaks
- Use a rubber band on each one to keep closed
- Clip bag to beaker
- Students will add iodine and make observations – changes will take place within a few minutes and the longer it sits, the darker it will become.
- Iodine is able to pass through the plastic bag, the starch is not
- Have students lift the bag out to see the changes that are taking place
Update – I let the set up sit over the weekend, and when I came in today, the water was almost completely clear – looks like just about all of the iodine moved into the bag:
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