Because I am out of the school building tomorrow and prefer not to have our substitute conducting a lab, I’ve decided to have students work through Lesson 70 and we will revisit Lesson 69 soon. For Lesson 70, students are welcome to review the Lesson 70 PowerPoint and then should work in small groups to complete the Lesson 70 Worksheet.
For additional background, watch the video below from Mr. Anderson of Bozeman Science:
To begin class, students received an extra 20 minutes to complete their Unit 3 Exams from last week. After that time (or before for students who were ready), students received the Lesson 68 Worksheet and Toxin Card Deck, along with a graphic organizer for analyzing the card deck. After the time for the exam concluded, we worked through the first few slides of the Lesson 68 PowerPoint, and students watched a video showing the chemical reaction written on the worksheet.
March 30: Today is the final day of the project – tomorrow you present your work to the class! To earn full credit for the presentation, you need to practice your presentation multiple times. Practice pronouncing all of the words, and look up the definitions of the words you are using to clearly indicate you understand what you are saying. The website Dictionary.com has a pronunciation feature – you can look up the definition of the word in question and also click the speaker to hear it pronounced. It also has a translate feature. If you are presenting with a partner, you need to decide in advance of your presentation who will say what. You both need to know the content and how to pronounce all of the words.
March 29: Remember to read the project outline carefully! For your presentation, you will make either a PowerPoint (Google Slides) or a poster. Poster paper is available in the cardboard box against the wall under the whiteboard with the daily bell schedule. For Google Slides presentations, you are welcome to include short videos (must be school appropriate!!!) depicting the reproductive strategies of one or both of the organisms you selected. Remember, presentation time is limited, so the videos must be brief, or you must identify a segment of the video to show in advance.
Need more challenge? Add an organism – but select one from a different biological kingdom than the organisms you have already researched. Remember, you must have two organisms in your presentation to earn full credit. However, for each additional organism you include, you will earn 5 points of extra credit! The six different kingdoms are pictured below:
March 28: Download the Organism Reproductive Strategies Project.
With many students out of class because of three different field trips happening today, we had to reschedule our quiz for tomorrow. For a starter activity today, students received a worksheet instructing them to write a paragraph comparing mitosis and meiosis, using 10 different key vocabulary words in their paragraph. Students who finished early had time to complete missing assignments.
Notes from the white board after 5th period are shown below:
With the Unit 3 exam scheduled for tomorrow, we took class time today to review key concepts for the exam. We focused much of the review on the concept of moles, with students having access to a set of practice problems and the answer key. We worked through most of the problems in class and the work from the white board is pictured below:
Class began with an entry task intended to provide students with practice identifying the four allele combinations possible from two different genes. A picture of the white board is shown below:
Next, we transitioned in to the lesson about Down Syndrome. We discussed the first three slides of the Down Syndrome Case Study slide deck and then detoured to the Wikipedia entry on aneuploidy. We focused on the Types section of the entry, examining how, of the autosomal chromosomes, only Trisomy 21 will result in a viable fetus most of the time. Students learned that when trisomy occurs in most of the other autosomal chromosomes, the result is an embryo that is non-viable, often resulting in miscarriage. There was a lot of student interest in learning more about polyploidy in the sex chromosomes, and students are encouraged to keep learning outside of class! There were also students curious about my use of Wikipedia. I explained that in my opinion, Wikipedia is a powerful research tool as long as the information included in an article is properly cited. Students can use a Wikipedia entry to locate primary source documents and then reference those documents directly once the information they contain has been verified. I referenced scientific publications that have determined Wikipedia to be as accurate as more traditionally accepted credible sources. Ironically, although Wikipedia is freely available, the publications determining the credibility of Wikipedia are not. Students interested in learning more without paying for the publications can read the Live Science article from 2011 titled “How Accurate is Wikipedia” as a starting point and come up with their own conclusions.
Back to the Case Study! To learn how Trisomy 21 occurs, students watched a short video illustrating non-disjunction. To put a human face on Trisomy 21, or Down Syndrome, students watched another short video about two young twins with Down Sydrome. Both videos are shown below:
The second video naturally leads to questions about twins, so slide 5 explains the difference between identical and fraternal (non-identical) twins. In slide 6, students are introduced to an adorable set of fraternal twins whose skin-color genetics will be revisited in our next unit. The embed feature of the video is deactivated, so here is the link to the ABC News video shown on YouTube.
Class concluded with a final look at the genetic phenomenon of X-inactivation. USing calico cats as the model, Mr. Anderson of Bozeman Science explains how in females, only one X chromosome is active in a given cell. We can visualize the result of this process in calico cats. At the end of the video, we explains how male calico cats, although extremely rare, can arise from the XXY phenotype (connecting back with our learning about aneuploidy).