What About the Stages of Mitosis?
Posted: Monday, June 20th, 2016
by Peter A’Hearn
The stages of mitosis are really important.
I’m not being sarcastic. Every cell in your body (save those used to make babies) went through the stages of mitosis. And if the stages of mitosis didn’t work with great precision at coordinating the dance of the chromosomes, you would not be a very well functioning human being. So the stages of mitosis are very important.
As a starting biology teacher, I spent much time and energy making sure my students knew the phases of mitosis. I brought in straw hats and flannel shirts and had my students do a “Mitosis Square Dance.” We tried to identify the phases in onion cells under the microscope. I came up with mnemonics so stupid I can’t remember them.
Turns out neither could the students. They would perform abysmally the first time they were tested on them, and by the time the final rolled around, only my two or three who remembered EVERYTHING knew them. This got me thinking about if they really were important. I had been taught them, and the book devoted considerable pages to them, so they must be something the students needed to know. I re-read the standards (the 98 standards at the time) and couldn’t find the stages of mitosis.
I did find meiosis (the baby making type of cell division) in the high school standards:
HS Biology 2a Students know meiosis is an early step in sexual reproduction in which the pairs of chromosomes separate and segregate randomly during cell division to produce gametes containing one chromosome of each type.
This got me reflecting on why I was teaching it. I couldn’t think of anything students could actually DO with their knowledge of the phases of mitosis. What real world problem could they understand or solve? It might come up on Jeopardy someday. It might come up on a college test– if magically they could remember something three of four years out that they couldn’t remember for a week. And in that case, the stages of mitosis would have been re-taught anyway.
Maybe a former student when they get to grad school will become involved in medical research involving understanding of and manipulation of the stages of mitosis. It would be cool to think so! If they do, they will have plenty of time for detailed study and will learn them in the ways that expert knowledge is learned, through deep engagement and problem solving. It would pretty arrogant as a high school teacher to think my square dances and silly mnemonics had anything to do with it.
So… what does this have to do with the NGSS? One of the challenges of implementation is that teachers are having a hard time deciding what to cut out. There are things teachers have taught and have come to accept as important knowledge that are not in the NGSS. If a teacher is thinking about NGSS as something to pile on top of everything you already teach, then transitioning to NGSS might seem like an impossible goal. We need to make hard choices about what to cut out.
Many teachers want to transition to NGSS but, at the same time, have a hard time letting go of content they have been teaching. Examples are the periodic table in 5th grade, the gas laws in high school chemistry, and lots of content in biology– the parts of the cell, the details of each body system, classification, and oh yeah, the stages of mitosis.
Does that mean that these details have no place in NGSS? Is NGSS just about vague generalities?
No! Our teaching under NGSS should be anchored in specific real world questions or problems so as not to be vague. A teacher could start with the problem of a genetic disease caused by mistakes in mitosis. This is true of many cancers. Using this context, students would learn as many details as needed to understand the problem and model their understanding. It’s not hard to see how several performance expectations could be bundled in a unit that is centered around genetic diseases. They might include:
HS-LS3-1: Ask questions to clarify relationships about the role of DNA and chromosomes in coding the instructions for characteristic traits passed from parents to offspring.
HS-LS1-1: Construct an explanation based on evidence for how the structure of DNA determines the structure of proteins which carry out the essential functions of life through systems of specialized cells.
HS-LS1-2: Develop and use a model to illustrate the hierarchical organization of interacting systems that provide specific functions within multicellular organisms.
And finally, the place where mitosis does occur in NGSS:
HS-LS1-4: Use a model to illustrate the role of cellular division (mitosis) and differentiation in producing and maintaining complex organisms.
The assessment boundary leaves the importance of the phases pretty clear:
Assessment Boundary: Assessment does not include specific gene control mechanisms or rote memorization of the steps of mitosis.
So in a unit like this, it would be clear that mitosis is very important. It helps understand where living things come from and how they develop. It can explain how genetic information is duplicated and how mistakes can be made that lead to both diversity and disorder. It also makes it clear that memorizing the details is not a productive use of time.
The transition to NGSS is an opportunity to reflect on what we teach: Is it deep? Does it help explain the real world? Will it result in lasting learning?
Posted: Wednesday, October 12th, 2016
by Jessica Sawko
In June 2016 California submitted a waiver application to discontinue using the old CST (based on 1998 standards) and conduct two years of pilot and field tests (in spring 2017 and 2018, respectively) of the new science assessment designed to support our state’s current science standards (California Next Generation Science Standards (CA-NGSS) adopted in 2013). The waiver was requested because no student scores will be provided as a part of the pilot and field tests. The CDE received a response from the U.S. Department of Education (ED) on September 30, 2016, which provides the CDE the opportunity to resubmit a revised waiver request within 60 days. The CDE will be revising the waiver request and resubmitting as ED suggested.
At its October 2016 North/South Assessment meetings CDE confirmed that there will be no administration of the old CST in the spring of 2017. (An archive of the meeting is available at http://www.cde.ca.gov/ta/tg/ai/infomeeting.asp.) Learn More…
Posted: Thursday, September 22nd, 2016
by Carol Peterson
1) To celebrate the 100th anniversary of the National Park Service, Google has put together a collection of virtual tours combining 360-degree video, panoramic photos and expert narration. It’s called “The Hidden Worlds of the National Parks” and is accessible right from the browser. You can choose from one of five different locales, including the Kenai Fjords in Alaska and Bryce Canyon in Utah, and get a guided “tour” from a local park ranger. Each one has a few virtual vistas to explore, with documentary-style voiceovers and extra media hidden behind clickable thumbnails. Ideas are included for use in classrooms. https://www.engadget.com/2016/08/25/google-offers-360-degree-tours-of-us-national-parks/. Learn More…
Posted: Thursday, September 22nd, 2016
CSTA is pleased to announce the winners of the 2016 CSTA Awards for Distinguished Contributions, Margaret Nicholson Distinguished Service Award, 2014 and 2015 PAEMST-Science recipients from California, and the 2016 California PAEMST Finalists. The following individuals and organizations will be honored during the 2016 California Science Education Conference on October 21- 23 in Palm Springs. This year’s group of awardees are truly outstanding. Please join us in congratulating them!
Margaret Nicholson Distinguished Service Award
The Margaret Nicholson Distinguished Service Award honors an individual who has made a significant contribution to science education in the state and who, through years of leadership and service, has truly made a positive impact on the quality of science teaching. This year’s recipient is John Keller, Ph.D. Dr. Keller is Associate Professor, Cal Poly San Luis Obispo and Co-Director, Center for Engineering, Science, and Mathematics Education, Cal Poly San Luis Obispo. In her letter of recommendation, SDSU science education faculty and former CSTA board member Donna Ross wrote: “He brings people together who share the desire to make a difference in the development and implementation of programs for science teaching. Examples of these projects include the Math and Science Teaching Initiative (MSTI), Noyce Scholars Program, Western Regional Noyce Initiative, and the Science Teacher and Researcher (STAR) program.” Through his work, he has had a dramatic impact on science teacher education, both preservice and in-service, in California, the region, and the country. He developed and implemented the STEM Teacher and Researcher Program which aims to produce excellent K-12 STEM teachers by providing aspiring teachers with opportunities to do authentic research while helping them translate their research experience into classroom practice. SFSU faculty member Larry Horvath said it best in his letter:“John Keller exemplifies the best aspects of a scientist, science educator, and mentor. His contributions to science education in the state of California are varied, significant, and I am sure will continue well into the future.” Learn More…
Posted: Tuesday, September 20th, 2016
by Peter A’hearn
NGSS is a big shift. Teachers need to learn new content, figure out how this whole engineering thing relates to science, and develop new unit and lesson plans. How could NGSS possibly make life easier?
The idea that NGSS could make our lives easier came to me during the California State NGSS Rollout #1 Classroom Example lesson on chromatography. I have since done this lesson with high school chemistry students and it made me think back to having my own students do chromatography. I spent lots of time preparing to make sure the experiment went well and achieved the “correct” result. I pre-prepared the solutions and organized and prepped the materials. I re-wrote and re-wrote again the procedure so there was no way a kid could get it wrong. I spent 20 minutes before the lab modeling all of the steps in class, so there was no way to do it wrong. Except that it turns out there were many. Learn More…
Posted: Tuesday, September 20th, 2016
by Robert C. Victor. Twilight sky maps by Robert D. Miller. Graph of evening planet setting times by Dr. Jeffrey L. Hunt
Our evening twilight chart for September, depicting the sky about 40 minutes after sunset from SoCal, shows brilliant Venus remaining low, creeping from W to WSW and gaining a little altitude as the month progresses. Its close encounter within 2.5° N of Spica on Sept. 18 is best seen with binoculars to catch the star low in bright twilight. The brightest stars in the evening sky are golden Arcturus descending in the west, and blue-white Vega passing just north of overhead. Look for Altair and Deneb completing the Summer Triangle with Vega. The triangle of Mars-Saturn-Antares expands as Mars seems to hold nearly stationary in SSW as the month progresses, while Saturn and Antares slink off to the SW. Learn More…