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Summary:
Today we studied the other kind of reproduction… the awkward kind of reproduction… sexual reproduction. We defined it as “a type of reproduction by which offspring arise from two parent organisms; each parent creates a sex cell with one mixed copy of each chromosome, then the cells are combined to form a brand new organism.” We started by discussing the human example (without too much detail!) and then students moved on to researching other examples. These included dragonflies, flowers, and even the gastric brooding frog. A copy of the worksheet is posted below.
Asexual Reproduction
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Summary:
We jumped into a new topic today called asexual reproduction. We defined it as “a type of reproduction by which offspring arise from a single parent organism and inherit the genes of that parent only.” This is very different from sexual reproduction, which will be tomorrow’s topic. Students spent the class researching various organisms that reproduce asexually, including strep bacteria, starfish, and even the Ebola virus. Check below for a copy of the worksheet.
Genetic Mutations
Summary:
Today we covered one of the more interesting topics within Unit 3: genetic mutations. We explained that genetic mutations can be defined as “a genetic mistake; a permanent change in the DNA code, such that the code differs from its parents.” We then discussed the two types of mutations (hereditary and acquired), what can cause them (sunburns, X-rays, smoking, etc.), and what the effects can be (aging, cancer, genetic diseases, etc.) At the end of class, we played a game where students rolled dice, picked a card, and added mutations to their genetic codes on Page 305. Copies of the genetic mutation cards and today’s PowerPoint can be found below.
Resources:
November 27 – Genetic Mutations (pg308).pptx
November 27 – Genetic Mutations Cards.docx
Discovering Genes
Summary:
We did a quick lesson today on how scientists detect, study, and classify genes. We defined a gene as “a portion of the DNA code that leads to the expression of a specific trait.” After that, students traveled around the classroom trying to discover various genes. And they did it in a similar fashion to how a scientist would: they compared the DNA of people who had a trait vs. those who did not. Then they wrote down which chromosome, and where on that chromosome, the gene could be found.
Resources:
November 22 – Discovering Genes (pg307).docx
November 22 – Genes Signs.pptx
A Cell for Me
Summary:
Today we started class with a simple goal: draw a picture of one of your human cells. Human beings are made up of trillions of cells. They’re microscopic. So how hard could it be? Actually… pretty hard.
Students had to include a strip of their DNA, color-coded to match yesterday’s genetic code. Then they had to add in the other 45 chromosomes as well. They also had to include a ribosome, some RNA, and a ribosome building a protein. And that’s not even every organelle. And in reality, each chromosome is millions of base-pairs long. So much for realism.
Resources:
November 21 – A Cell for Me (pg306).docx
The Code for Me
Summary:
In class today, students completed an activity where they tried to determine their own genetic code. Of course this is impossible; the real human genome is about 6 billion base pairs long. So our activity was a mixture of both fact and fiction.
Students went through each of the 23 pairs of human chromosomes and filled in on gene that can be found on each. For example, a gene for curly hair can be found on Chromosome 1, while there is a gene associated with “thrill seeking” located on Chromosome 11. Students went through the packet, analyzing their traits and filling in their code, and finished off with a self-portrait.
Resources:
November 20 – The Code for Me (pg305).pdf
DNA Lab
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Summary:
Today was our DNA Lab. Students worked in pairs trying to extract DNA from human cheeks cells. It’s tricky. Cheek cells are large and it’s hard to get very many of them, so collecting a visible amount of DNA is a delicate task. The basic steps included getting a sample of cheek cells, breaking the cell membranes using soap, unraveling the DNA using meat tenderizer, using alcohol to isolate the DNA, and then observing (see video above). You can find a copy of the lab posted below. All in all, it was a challenging yet productive day.
Resources:
November 17 – DNA Lab (pg304).docx
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