Evolution: Evolving Bodies, Evolving Switches

Today, students watched the HHMI Biointeractive video titled Evolving Bodies, Evolving Switches (watch below).  The video explains how the stickleback fish has evolved and adapted to its environment, and shows how scientists are using genetics to further understanding of evolution as well as developmental biology.  After watching the video, students completed a worksheet to reinforce and extend their learning.

Evolution: Evolution Unit Review

With the extra advisory period inserted into the day to enable students to complete the final school-wide writing to explain assessment, we used the shortened class period to review the learning thus far in the evolution unit.  We crowd-sourced a set of class notes and an example from one of the class periods is pictured below.  We covered the major learning concepts from the Cosmos video, the malaria/sickle cell case study, the icefish video, and the evolution of Darwin’s finches.

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Toxins: Mass-Mole Conversions

Lesson 78 provided students with additional practice converting from mass to moles and from moles to mass.  The Lesson 78 PowerPoint ChemCatalyst activity asked students to predict whether arsenic (As), arsenic oxide (As2O3), or arsenic sulfide (As2S3) was most toxic.  Students had to consider how many atoms of arsenic are in each molecule, and which has more molecules in a fixed mass.  Some of the work from the entry task is shown below:

For the Lesson 78 Worksheet, students worked in pairs to complete the questions.  For homework, students were assigned questions 5-8 from the textbook.

Toxins: Molar Mass

Today’s work began with the ChemCatalyst from the Lesson 77 PowerPoint.  Students considered the question for a few minutes and were once again reminded how abstract the idea of the mole really is.  To help bring the concept of the mole to life, students worked through the Lesson 77 Worksheet.  The worksheet consisted of two parts, with Part 1 asking students to work through some of the math behind calculating molar mass.  Then in Part 2, students participated in a lab activity where they were able to actually measure out and visualize what one mole of various materials look like.  Students worked with water, table salt, aluminum, nickel, and iron.  For homework, students were assigned textbook questions 5-7.

Answers for Part 1 are shown below:

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Evolution: The Beak of the Finch

After an eventful start to the day in which we briefly lost power at our school and our digital classroom wall clocks are hours off, we decided to start the class period with Jack Horner’s entertaining TED Talk in which he describes his research connecting dinosaurs and chickens.

After the video, we returned to our discussion of Darwin’s finches from yesterday’s lesson.  Students watched the HHMI video The Beak of the Finch (below) and then set to work on the accompanying worksheet packet.  We will continue our work tomorrow during the short Friday class period.  Students who finish early are encouraged to try the Finch Song Activity on the HHMI website.

Evolution: Retroviruses, Pseudogenes, and Transposons

Occasionally we need to learn content that involves a lecture-style delivery with students taking lots of notes.  Today was one of those days.  The PowerPoint includes content as well as links to the videos we watched.  Briefly, students were introduced to Linnaeus, Lamarck, and Darwin for some background information on how our understanding of evolution has changed over time.  We then transitioned into learning about concepts that help explain how the DNA available to an organism can change over time, and how changes in DNA can be used as a tool to track the relationships between species.  The videos embedded in the PowerPoint are also provided below:

Toxins: Avogadro’s Number

For Lesson 76, students gained practice working with scientific notation in the context of Avogadro’s Number (really big numbers) and the mass of small numbers of particles (really small numbers).  We began class by working through part B of the ChemCatalyst from Lesson 75.  Notes from the work are shown below:

We then transitioned into the Lesson 76 Worksheet (we did not use the Lesson 76 PowerPoint but it is provided here for reference).  We worked through some of the table on page 2 of the worksheet, and then students used the remainder of the class period to work together to complete the worksheet.  For homework, students were assigned to complete any 3 problems from the textbook.

Evolution: Mutations and the Birth and Death of Genes

As an entry task, students watched the HHMI video Mutations and the Birth and Death of Genes, which explains how icefish have evolved to live in the frigid waters of the Antarctic.

Students completed and turned in the icefish video worksheet after the video, and then transitioned to a review of our work from yesterday.  Using the Chromebooks, students navigated to yesterday’s post on the class website and analyzed the data, using their findings to write a summary paragraph explaining how the data provides evidence in support of the Theory of Evolution.  Instructions from the white board are shown below:

For students who would like to learn more about gene mutations (both the loss of gene function, as well as when genes are re-activated), check out this interesting scientific article about The Genetics of Vitamin C Loss in Vertebrates.