Misconceptions in Cell Biology

“Every living thing is made of cells, and everything a living thing does is done by the cells that make it up.”
L.L. Larison Cudmore

Cells are the building blocks of all biology.  Every living organism is composed of cells.  All cells came from preexisting cells.  If you are a trained biologist, you recognize the last two sentences as The Cell Theory, one of the core theories of modern biology.  A lot of The Cell Theory seems basic considering what we know.  However, remember cells are smaller than can be seen by the naked eye.  Until the invention of microscopes, we didn’t even know cells existed.  The word cell was first used by Robert Hooke in the 1660s while examining thin slices of cork.  Hooke used the word cell to describe the structures he observed because they reminded him of the rooms of monks.

Additionally, it wasn’t until Loise Pasteur’s famous swan-necked flask experiment in 1859 that the idea of spontaneous generation, life spontaneous occurring out of organic material, was disproven.  Therefore, every cell must come from a preexisting cell. With the importance of The Cell Theory, it is not surprising that students spend a lot of time learning about the structure, function, and behavior of cells.  However, because cells are not visible to the naked eye, it is not surprising that many students have misconceptions concerning cells.

What is a misconception? Scientific misconceptions “are commonly held beliefs about science that have no basis in actual scientific fact. Scientific misconceptions can also refer to preconceived notions based on religious and/or cultural influences. Many scientific misconceptions occur because of faulty teaching styles and the sometimes-distancing nature of true scientific texts.”  When we teach students biology, how good are we at dealing with misconceptions?  The critical questions are what the student’s misconceptions are and how do we deal with them?

Musa Dikmenli looked at the misconceptions that student teachers had in his article Misconceptions of cell division held by student teachers in biology: A drawing analysis.  In the study, Dikmenli examined the understanding of 124 student teachers in cell division.  According to the study, these student teachers “had studied cell division in cytology, genetics, and molecular biology, as a school subject during various semesters.”  Therefore, the student teachers had already studied cell division at the college level.

At a basic level, cell division is the process of a single cell dividing to form two cells.  Scientists organize cell division (the cell cycle) into 5 phases Interphase, Prophase, Metaphase, Anaphase, and Telophase.  The cell cycle is often depicted using a circle. 

Figure of the cell cycle at different levels of detail. Created by PJ Bennett
Figure of the cell cycle at different levels of detail. Created by PJ Bennett

Instead of answering quiz questions or writing essays, the students were “asked to draw mitosis and meiosis in a cell on a blank piece of A4-sized paper. The participants were informed about the drawing method before this application.” (Dikmenli) The use of drawing as an analysis method has several advantages.  The most important of which is that it can be used across languages and by students in multiple nationalities.

After analyzing the drawings, almost half of the student teachers had misconceptions about cell division.  Some of the most come misconceptions are, when DNA synthesis occurs during mitosis and mistakes about the ploidy, the number of chromosome copies, during meiosis.  The research results mean that individuals that are going to teach biology at the primary and high school level are likely to pass their misconceptions along to their students.

So, where does the problem with student misconceptions start?  Students learn misconceptions from their teacher about cell division.  However, the teachers all have biology degrees from colleges, and their college faculty failed to address their misconceptions. However, perhaps we are not asking the correct questions.  Instead of trying to decide who, K-12 or College, is responsible for correcting student misconceptions, we should ask why students get through any level of school with misconceptions?

I can hear all the teachers now, while obviously, students get through school with misconceptions because it’s difficult to correct misconceptions. However, we know a lot about teaching to correct misconceptions.  Professor Taylor presents one method, refutational teaching in the blog post GUEST POST: How to Help Students Overcome Misconceptions.  With a quick Google search, you can find other supported methods.  In all cases getting the student to overcome the misconception, the student must actively acknowledge the misconception while confronting countering facts.

It is unlikely that the problem is that it is hard to teach to misconceptions, let’s be honest most teachers at any level are willing to use whatever techniques work.  No, I suspect the real problem is that most teachers don’t realize their students have misconceptions. So, then the real questions are why instructors don’t realize students have misconceptions.  In this case, I suspect it is the method of assessment.

Most classroom assignments and assessments ask the students to provide the “right” answer.  The right answer is especially prevalent in the large lecture class where multiple-choice questions are common.  However, the fact that a recent review article A Review of Students’ Common Misconceptions in Science And Their Diagnostic Assessment Tools covers 111 research articles suggest that identifying misconceptions is not complicated if teachers use the correct methods.  Therefore, the incorporation of the proper assessment methods alongside teachers’ standard methods will help teachers identify student misconceptions.

However, it is not good enough to identify misconceptions. The misconceptions must be identified early enough in the course so the teacher can address them.  Finding misconceptions is a perfect justification for course pretests either comprehensively at the beginning of the course or smaller pretests at the start of unites.  In an ideal world, pretests would be a resource that departments or schools would build, maintain and make available to their teachers ideally as a question bank.  Until schools provide resources to identify misconceptions, think about adding a pretest to determine your student’s misconceptions.  It will help you do a better job in the classroom

Thanks for Listing to My Musings
The Teaching Cyborg

Double-Blind Education

“It is a capital mistake to theorize before one has data.”
Arthur Conan Doyle (via Sherlock Holmes)

Several years ago, I was attending a weekly Discipline-Based Educational Research (DBER) meeting. Two senior faculty members led and organized the weekly meetings.  Both faculty members had trained in STEM disciplines.  One had received their educational research training through a now-defunct National Science Foundation (NSF) program, while the other was mostly self-taught through multiple calibrations with educational researchers.

The group was discussing the design of a research study that the Biology department was going to conduct.  One of the senior faculty members said if they were serious, they would design a double-blind study.  The other senior faculty member said that not only should they not do a double-blind study, but a double-blind study was likely a bad idea. I don’t recall the argument over double-blind studies in education ever getting resolved. We also never found out why one of the faculty members thought double-blind studies were a bad idea in educational research.

Double-blind studies are a way to remove bias. Most people know about them from drug trials.  Educational reform is not likely to accidentally kill someone if an incorrect idea gets implemented due to a bias in the research.  However, a person’s experiences during their education will certainly have a lifelong impact.  While double-blind studies might be overkill in education research, there is the question of what is enough.  As I have said before, it is the job of educators to provide the best educational experience possible; this should extend to our research.

How do faculty know how they should teach? What research should faculty members use?  Should we be concerned with the quality of educational research? Let me tell you a story (the names have been changed to protect the useless).  A colleague of mine was looking for an initial research project for a graduate student. My college told me about a piece of educational “research” that was making the rounds on his campus.  Alice, a well-respected STEM (Science Technology Engineering and Math) faculty member, had observed her class.  She noted what methods of note-taking her students were using.  At the end of the semester, she compared the method of notetaking to the student’s grade. On average, the students that used the looking glass method of notetaking had grades that avraged one letter grade lower than the other method of notetaking.

Alice told this finding to a friend the Mad Hatter, a DBER (Discipline-Based Education Research) expert.  The Mad Hatter was so impressed with the result that he immediately started telling everyone about it and including it in all his talks.  Now because Alice did her study on the spur of the moment, she did not get research approval and signed participation agreements.  The lack of paperwork meant that Alice couldn’t publish her results.  With such a huge effect, my colleague thought repeating this study with the correct permissions so that it could be published would be perfect for a graduate student.

They set-up the study; this time, to assess what methods the students were using to take notes, they videotaped each class period.  Additionally, the researchers conducted a couple of short questioners and interviewed a selection of the students.  After a full semester of observation, the graduate students analyzed the data. The result, there was no significant difference between looking glass notetaking and all the other types.  Just a little while ago, I saw a talk by the Mad Hatter. It still included Alice’s initial results.  Now the interesting thing is neither Alice nor the Mad Hatter would have excepted Alice’s notetaking research methodology if it was a research project in their STEM discipline.  However, as an educational research project, they were both willing to take the notetaking results as gospel.

While there is a lot of proper educational research, researchers have suggested that a lot of faculty and policymakers have a low bar for what is acceptable educational research.  The authors of We Must Raise the Bar for Evidence in Education suggest a solution to this low bar in educational research.  Their recommendation is to change what we except as the basic requirement of educational research.  Most of the author’s suggestions center around eliminating bias (the idea at the core of the double-blind study) their first suggestion is,

“to disentangle whether a practice causes improvement or is merely associated with it, we need to use research methods that can reliably identify causal relationships. And the best way to determine whether a practice causes an outcome is to conduct a randomized controlled trial (or “RCT,” meaning participants were randomly assigned to being exposed to the practice under study or not being exposed to it).”

One of the biggest problems with human research, which includes educational research, is the variability in the student population.  As so many people are fond of saying, we are all individuals.  By randomly assigning individuals to a group, you avoid the issue of concentrating traits in one group. 

Their second suggestion is, “policymakers and practitioners evaluating research studies should have more confidence in studies where the same findings have been observed multiple times in different settings with large samples.”  The more times you observe something, the more likely it is to be true (there is an argument against this, but I will leave that for another time.)

Lastly, the authors suggest, “we can have much more faith in a study’s findings when they are preregistered. That is, researchers publicly post what their hypotheses are and exactly how they will evaluate each one before they have examined their data.”  Preregistration is a lot like the educational practice used with student response systems were the student/researcher is less likely to delude themselves about the results if they must commit to an idea ahead of time.

If we are going to provide the best educational experiences for our students, we need to know what the best educational experiences are.  However, it is not enough to conduct studies. We need to be as rigorous as possible in our studies.  The next time you perform an educational research project, take a minute, and ask yourself how I can make this study more rigorous.  Not only will your students benefit, so will your colleagues. Thanks for Listing to My Mussing
The teaching Cyborg

Much Ado about Lectures

“Some people talk in their sleep. Lecturers talk while other people sleep”
Albert Camus

The point of research is to improve our knowledge and understanding.  An essential part of research is the understanding that what we know today may be different from what we know tomorrow as research progresses, our knowledge changes.  Conclusions changing over time does not mean the earlier researchers were wrong. After all, the researchers based their conclusions on the best information; they had available at the time.  However, future researchers have access to new techniques, equipment, and knowledge, which might lead to different conclusions.  Education is no different. As research progresses and we get new and improved methods, our understanding grows.

Out of all the topics in educational research, the most interesting is the lecture.  No subject seems to generate as much pushback as the lecture.  A lot of faculty seems to feel the need to be offended for the lecture’s sake.  Anyone that has trained at a university and received a graduate degree should understand that our understanding changes over time.  Yet no matter how much researchers publish about the limited value of the lecture in education, large numbers of faculty insist the research must be wrong.

I suspect part of the push back about the lectures is because lecturing is what a lot of faculty have done for years.  If they except that the lecture is not useful, then they have been teaching wrong.  Faculty shouldn’t feel bad about lectures; after all, it is likely what they experienced in school.  I think it is the faculty member’s own experience with lectures as students that lead to the problem.  I have had multiple faculty tell me over the years some version of the statement “The classes I had were lectures, and I learned everything, so lectures have to work.”

The belief that you learned from lectures when you where a student is likely faulty.  The reason this belief is defective is that you have probably never actually had a course that is exclusively a lecture course.  I can hear everyone’s response as they read that sentence, “what are you talking about as a student most of my classes were lectures.  I went into the classroom, and the teacher stood at the front and lectured the whole period. So, of course, I have had lecture courses.”

Again, I don’t think most people have ever had an exclusive lecture course. Let’s braked down a course and see if you really can say you learned from the lecture.  First, did your course have a textbook or other readings assignments?  Just about every course I took had reading assignments.  In most of my classes, I spent more time reading then I spent in the class listing to the lecturer.  Most of my courses also had homework assignments and written reports.  Many of the courses also had weekly quizzes, and one or two midterms were we could learn from the feedback.

Can you honestly say that in a lecture course, you didn’t learn anything from the course readings?  That you didn’t learn anything from the homework assignments and papers. That you didn’t learn anything by reviewing the graded homework assignments, papers, quizzes, and midterms, the truth is even in a traditional lecture course, there are lots of ways for students to learn.  As a student, it is next to imposable to determine how much you learn from any one thing in a course.  So, with all these other ways to learn in a “Lecture” course, can you honestly say you learned from the lecture?  In truth, the only way to have a course where you could say you learned from the lecture is if you had a course that only had a lecture and final, no readings, no assignments, no exams with feedback, only a lecture.

However, there is an even deeper issue with the lecture, then the faculty insisting it works (without any real evidence.)  As faculty members, what should our goal as a teacher be?  It is quite reasonable to say that anyone teaching at a college, university, or any school should attempt to provide the best learning environment they can.  So, even if we accept the argument that students can learn from, let’s call it, a traditional lecture (I don’t) if the research says there is a better way to teach shouldn’t we be using it?

If faculty approach teaching based on what is the best way to teach, it does not matter if students can learn from lectures if there is a better way to teach, we should use it.  The research says we should be using Active Learning when we teach because it benefits the students.  A recent article, Active learning increases student performance in science, engineering, and mathematics from PNAS show that students in classes that don’t use active learning are 1.5 times more likely to fail the course.  At a time when universities and the government are pushing for higher STEM graduation rates, active learning would make a big difference.

So how much of a problem is the lecture?  I know a lot of faculty that say they use active learning in their classrooms.  In a recent newsletter from the Chronicle of Higher Education, Can the Lecture Be Saved? Beth McMurtrie states, “Most professors don’t pontificate from the moment class starts to the minute it ends, but lecturing is often portrayed that way.”

However, a recent paper from the journal Science Anatomy of STEM teaching in North American universities might refute this statement.  The Science paper shows, at least in the STEM disciplines, that when classroom teaching methods are observed rather than reported by survey, 55% of all the course observed are traditional lectures.  Only 18% of the courses are student-centered active learning environments.  The rest have some amount of active learning.

Regardless of whether you think the lecture works or not, it is long past time to change.  There is no reason to feel ashamed or think poorly about faculty that used lectures in the past.  After all, for a lot of reasons, lectures where believed to work.  However, we are also long past the time where anyone should be offended for the lecture’s sake.  We need to use the best teaching methods currently available.  The best methods are the techniques called active learning because students measurably learn better than in a traditional lecture.

Thanks for Listing To my Musings
The Teaching Cyborg

Is it Dedication or Delusion?

“Delusion is the seed of dreams.”
Lailah Gifty Akita

Educational reform is a never-ending process, which is, in many ways, good.  The purpose of educational institutions is to provide the best education possible.  The individual teacher learns from experience and improves over time.  Research into learning and cognition lead to better understandings of how people learn and therefor better ways to teach.

However, even with our continually improving knowledge, changes in education seem painfully slow or to not occur at all.  A consistent problem is classroom size.  While just about anyone that has studied education will agree that the best way to teach someone is with a dedicated teacher in a one on one environment (feel free to disagree I would love to hear your reasons). However, in a society that wants education especially higher education available to everyone one on one education is not possible.

Don’t believe me look at the numbers.  According to the US census bureau, there are 76.4 million students in school K through University.  That means we would need 76.4 million teachers if we paid them an average living wage including overhead each teacher would make $41,923 – $46,953 (still a little low if you ask me)  this works out to 3.2 – 3.5 trillion dollars or 17-19% of the US Gross National Product.  As a comparison, the budget for the US national government was 21% of the GDP in 2015.  Also, 76.4 million students are 24.7% of the US population, three and older, if we also had 24.7% of the US population working as teachers, then almost half of the US population would be students or teachers. Remember we would still need all the support staff, and these are with current numbers, not what we would need for everyone eligible for school.

I don’t think any country can afford to devote that much of their population and resources to one thing and survive.  As someone that loves education, I would love it if some economist out there proves me wrong.  So, class size is a compromise between what we can afford to do and the best environment for our students.

However, outside of issues that are constrained by shall we call it a reality.  We have all seen programs and projects that we think can help students get canceled.  We have all seen programs developed by grants get canceled the second the grant ends.  The loss of these programs is not only that future students will not benefit, but also the loss of resources, including time, commitment, and motivation of staff.

I have been asked after several of my programs have been canceled “how many times are you going to keep building programs that just get canceled?” It’s an interesting question and one that is not easy to answer.  I was at the University of Colorado Boulder when Carl Wieman won the 2001 Noble prize for Physics.  After winning the Nobel prize, Wieman went on to advocate for the improvement of science education.  To the extent that he was appointed the White House’s Office of Science and Technology Policy Associate Director of Science in 2010.  In 2013 I remembered reading an article Crusader for Better Science Teaching Finds Colleges Slow to Change that was about Dr. Weiman and his frustrations with the slow changes in higher education “… Mr. Wieman is out of the White House. Frustrated by university lobbying and distracted by a diagnosis of multiple myeloma, an aggressive cancer of the circulatory system, he resigned last summer. … “I’m not sure what I can do beyond what I’ve already done,” Mr. Wieman says.”

You can’t help but think if someone with the prestige and influence of Carl Weiman can’t encourage change what hope does anyone else have.  The truth of the matter is that how much someone can take and when they have had enough is a personal question.  When thinking about how much is enough, I can’t help but think of a humorous little fable Nasreddin and the Sultan’s Horse.  I have encountered versions of this fable many times.  I think the first time was in the science fiction book The Mote in God’s Eye by Larry Niven and Jerry Pournelle.

Nasreddin and the Sultan’s Horse

One day, while Nasreddin was visiting the capital city, the Sultan took offense to a joke that was made at his expense. He had Nasreddin immediately arrested and imprisoned; accusing him of heresy and sedition. Nasreddin apologized to the Sultan for his joke and begged for his life; but the Sultan remained obstinate, and in his anger, sentenced Nasreddin to be beheaded the following day. When Nasreddin was brought out the next morning, he addressed the Sultan, saying “Oh Sultan, live forever! You know me to be a skilled teacher, the greatest in your kingdom. If you will but delay my sentence for one year, I will teach your favorite horse to sing.”

The Sultan did not believe that such a thing was possible, but his anger had cooled, and he was amused by the audacity of Nasreddin’s claim. “Very well,” replied the Sultan, “you will have a year. But if by the end of that year you have not taught my favorite horse to sing, then you will wish you had been beheaded today.”

That evening, Nasreddin’s friends could visit him in prison and found him in unexpected good spirits. “How can you be so happy?” they asked. “Do you really believe that you can teach the Sultan’s horse to sing?” “Of course not,” replied Nasreddin, “but I now have a year which I did not have yesterday, and much can happen in that time. The Sultan may come to repent of his anger and release me. He may die in battle or of illness, and it is traditional for a successor to pardon all prisoners upon taking office. He may be overthrown by another faction, and again, it is traditional for prisoners to be released at such a time. Or the horse may die, in which case the Sultan will be obliged to release me.”

“Finally,” said Nasreddin, “even if none of those things come to pass, perhaps the horse can sing.”

In 2017 I read an article from Inside Higher Ed Smarter Approach to Teaching Science.  The article talks about a book (Improving How Universities Teach Science: Lessons from the Science Education Initiative) written by Carl Weiman that documents the research and methods to improve science teaching in higher education.  It seems that Dr. Weiman did not give up after all, and he is back and still pushing.  Perhaps the truth is that people that try and change the monolith must be a little bit crazy if crazy is doing the same thing repeatedly and expecting a different outcome. Then again, maybe the horse will learn to sing.

Thanks for Listing to My Musings
The Teaching Cyborg

Teaching Sciences: Where Should We Start

“Chemistry ought to be not for chemists alone.”
Miguel de Unamuno

Recently a video showed up on LinkedIn.  The video was a demonstration of an Augmented Reality (AR) app The Atom Visualizer made by Machine HaloThe Atom Visualizer is the first ARCore app.  In the LinkedIn demo video, the app functions with chemistry flash cards.  The demo is not the first AR flashcards several already exist, like AR Flashcards and AR Talking Cards, to name a couple.  The Atom Visualizer is the first app to use Google’s AR framework ARCore.

While there is a lot to discuss with respects to AR and education, one person compared it to televisions and said it therefor would never work.  Another talked about problems with implementation.  However, I might talk about these issues another time.  What stood out to me as I looked over the comments were comments about chemistry and education.

S., A.
“I am glad to see something like this, but unfortunately this is sending a wrong note. For ex: Oxygen is never O, it is O2 & 2 atoms of Hydrogen combine with 1 O2 atom to form H2O Sodium as Na doesn’t react with Chlorine directly, it instead reacts with HCL (Hydrochloric acid) to form H20 & NaCl.
It would be wonderful if we teach them right things right & help humanity learn faster!!” (retrieved Aug 12, 2019, from https://www.linkedin.com/posts/ajjames_augmentedreality-ar-innovation-activity-6562906886130241536-wNCY/)

A., I.
“I would like to note that electrons are not volumetric particles (spheres) that orbit the atom nucleus, indeed they are present around the nucleus in the form of electron cloud, this is the probability of finding the electron at a certain point with respect to the atom. Additionally, the electron is a volume less particle. I would be amazed if really the correct model is shown and not some old classical physics incorrect info. This old model caused a lot of students to confuse chemistry as they go a little deeper into the subject.” (retrieved Aug 12, 2019, from https://www.linkedin.com/posts/ajjames_augmentedreality-ar-innovation-activity-6562906886130241536-wNCY/)

M., C.
“Interesting idea, but the shape of the water molecule is wrong. There are some cool (free) apps that display correct geometries though :)” (retrieved Aug 12, 2019, from https://www.linkedin.com/posts/ajjames_augmentedreality-ar-innovation-activity-6562906886130241536-wNCY/)

I would say these comments are both correct and incorrect at the same time.  After all, since the demonstration video only shows a few cool looking animations, we don’t know what the educational objective the creator of the cards was trying to achieve.  The video itself would have been much more effective presented as a 1 – 2-minute teaching lesson.  After all, perhaps the creator was trying to help people connect molecular formulas to materials H2O (water) NaCl (table salt).  In that case, the cards are not that bad.

If they are trying to teach chemical reactions, then the cards have several problems.  However, even if they are trying to explain chemical reactions should the electrons be displayed as clouds or discrete bodies.  Anyone that has a chemistry degree knows that electron clouds are the correct representation.  However, to understand electron clouds, you need to get into quantum mechanics. Leaving aside the question of whether the students have the math skills to truly delve into quantum mechanics are they ready to learn quantum mechanics.

Anyone that teaches knows we can’t learn everything all at once.  Also, successful education requires a framework to build on.  Students incorporate new information into existing knowledge.  That information needs a starting point.  One of the problems with chemistry is that we can’t directly observe a lot of the things we teach.  In cases like this, models and cartoons are a good starting point. 

Using representations, we can start building up knowledge.  The dotes make it easier for students to understand that covalent bonds are a sharing of electrons and that two atoms bound together share electrons.  Does that come across to early student if we use two or three different shaped clouds?  While an understand stoichiometry and what form elements take in the environment, they need to understand chemical bonds and the role electrons play. 

The important thing about teaching tools and models is to use them where they are appropriate. Representations like dot structure are not intended to teach students the physical structure and form of electrons. Educations is not merely the process of moving from simple to complex but also building up a framework and helping student incorporate new and more complex information. The introduction of misconceptions in STEM education is rarely because teachers present the wrong information but because the tools are misused.  

Still I wonder when and how we should start teaching quantum mechanics?

Thanks for Listing to My Musings
The Teaching Cyborg

If We Want to Discuss Scientific Ethics, We Need to Teach Scientific Literacy

Science literacy is the artery through which the solutions of tomorrow’s problems flow.”
Neil deGrasse Tyson

Late last year a Chinese scientist He Jiankui announced that his team had created two genetically engineered human embryos that lead to the birth of two female siblings.  I wrote an article about why this shouldn’t have surprised anyone (It Might Have Happened, We Don’t Know for Sure, But Now We Freak.) While there may still be some questions, all the technology needed currently exists.

In June 2019 Russian scientist Denis Rebrikov announced that he plans to seek approval from several government agencies to perform a similar experiment to He Jiankui. It is not currently clear that human genetic engineering is legal under Russian law, or that Dr. Rebrikov will receive approval for his trial.

Beyond genetically engineering humans a few days ago (Aug 3, 2019) a report came out about the creation of a Human-Monkey chimera First Human–Monkey Chimeras Developed in China. Professor Juan Carlos Izpisúa Belmonte’s group of the Salk institute conducted the experimented in China.  According to the report, the scientists chose to perform the research in China to avoid legal issues. The same group produced a human-pig chimera in 2017.

On top of questions concerning human experimentation, there are questions about Genetically Modified Organisms (GMOs).  Just like debates about human genetic engineering, the discussions about GMOs are occurring after the fact.  Today more then 90% of the Hawaiian Papaya crop is Genetically modified (How GMO Technology Saved the Papaya).  Other conventional crops like corn, soybeans, and canola oil are also mostly GMO.

I could continue listing procedures that are emerging that have or will have ethical debates associated with them.  However, if we are going to have meaningful discussions, it is essential that individuals have a basic scientific understanding.  Specifically, what are the techniques scientists use and why were they chosen.  What is genetic engineering?  What is a Chimera?  What are stem cells?  Why are we interested in these techniques?  Why should we use them? 

Let’s start with the basics according to Merriam Webster

  • Genetic engineering: the group of applied techniques of genetics and biotechnology used to cut up and join together genetic material and especially DNA from one or more species of organism and to introduce the result into an organism in order to change one or more of its characteristics
  • Chimera: an individual, organ, or part consisting of tissues of diverse genetic constitution
  • Stem cells: an unspecialized cell that gives rise to differentiated cells

While a few of these definitions could lead to additional questions, what does “diverse genetic constitution” mean, I can live with them.  These definitions would be a good starting point for discussions in class.  However, a lot of today’s society is like to go to Wikipedia instead of the dictionary.

  • Genetic engineering: Genetic engineering, also called genetic modification or genetic manipulation, is the direct manipulation of an organism’s genes using biotechnology.
  • Chimera: A genetic chimerism or chimera (/kaɪˈmɪərə/ ky-MEER-ə or /kɪˈmɪərə/ kə-MEER-ə, also chimera (chimæra) is a single organism composed of cells with distinct genotypes.
  • Stem cells: Stem cells are cells that can differentiate into other types of cells, and can also divide in self-renewal to produce more of the same type of stem cells.

Fortunately for society, many of these definitions are excellent; in fact, the Wikipedia definition of Genetic Engineering and Stem cells is probably better than Merriam Webster’s definition.

So that means that GMOs are the product of Genetic Engineering. So why would you want to create GMOs?  There are lots of reasons let’s talk about Golden rice.  Golden rice is a GMO designed to combat vitamin A deficiency.  Due to starch content, white rice is a good source of calories. However, rice lacks several essential nutrients (including vitamin A).

To combat Vitamin A deficiency, scientists engineered rice to produce β-carotene, which the human body turns into vitamin A.  Scientists created Golden rice by the insertion of two genes into the rice genome.  The final product is rice, that is a golden color and provides β-carotene.  So, in the case of golden rice, the reason for genetic engineering was to combat malnutrition. Other researchers are trying to create crops that need less fertilizer or pesticides, that have better yields, or to do less damage to the soil.

There are people that no matter what the goal is will say GMOs should be outlawed.  The question, of course, is why? After all, we have been modifying our food for thousands of years.  Let’s talk about Cauliflower.  The many types of cabbage, broccoli, kale, kohlrabi, and cauliflower are all descended from the same plant. Brassica oleracea also called wild cabbage (The extraordinary diversity of Brassica oleracea).

Brassica oleracea (wild cabbage) photo by Kurt Kulac,. Licensed under the Creative Commons Attribution-Share Alike 2.5 Generic license.
Brassica oleracea (wild cabbage) photo by Kurt Kulac,. Licensed under the Creative Commons Attribution-Share Alike 2.5 Generic license.

Over thousands of years farmers selected for traits they found desirable, leading to all the variants, many of which don’t even look like the same plant like cauliflower.

A cauliflower plant photographed by Bloemkool. Licensed under the Creative Commons Attribution-Share Alike 3.0 Unported license.
A cauliflower plant photographed by Bloemkool. Licensed under the Creative Commons Attribution-Share Alike 3.0 Unported license.

Research into Arabidopsis thaliana flower development by scientists using a mutagen (a chemical compound that creates changes in DNA) to create mutations.  One of these mutations produced plants that looked like cauliflower (Molecular basis of the cauliflower phenotype in Arabidopsis).  Additional research showed that the gene muted in Arabidopsis to produce the cauliflower phenotype was the same naturally occurring mutation in Brassica oleracea that was selected to produce cauliflower.

The research into plant development means that I could reproduce cauliflower in three different ways.  One, I could selectively breed Brassica oleracea to produce cauliflower.  Two, I could create mutations in Brassica oleracea using chemical mutagens and select for cauliflower.  Three, since we know the gene, I could use genetic engineering to create cauliflower from Brassica oleracea.  Most importantly done correctly, I could produce cauliflower using all three of these methods, and genetically, they would be identical.  However, even though there would be no difference between the three varieties, people would insist that the GMO cauliflower caused all kinds of problems, why?

While GMOs are already out in the wild and because of the spread of pollen, it is unlikely that society will ever put GMOs back in the box.  With several of the recent occurrences, it might also be too late for human genetic engineering, human GMOs.  Now let’s talk about Chimera’s. 

One of the primary goals for human-monkey or human-pig chimeras is the production of organs for transplant.  A common statistic is that 20 people die every day in the US waiting for a transplant. In the case of organ transplants, individuals would donate cells that scientists combine with an early pig embryo. The human cells would then give rise to the lungs, which doctors would transplant.  Currently, scientists have not produced chimeras with enough human cells to create organs that are viable for transplant.  However, it is only a matter of time until this becomes possible.  Will people wait until the first transplant occurs to talk about chimeras?

However, just as significant as the question, “will we discuss something before it happens?” Is the question of whether we are doing enough to teach science so the general society can adequately discuss the issues?  How important do you think science classes for nonmajors are?  Nonmajors class might make all the difference to the future of scientific research and medical improvements.

Thanks for Listing to My Musings
The Teaching Cyborg

Increasing STEM Graduation Numbers

“You cannot teach a man anything; you can only help him discover it in himself.”
Galileo

For decades the United States government has told us that we need to turn out more STEM graduates.  I remember hearing in my youth the government talk about needing more science graduates; Rita Colwell had not yet coined the term STEM.

On December 18, 2012, President Barack Obama announced a plan to add 1 million more STEM graduates over the next decade (Obama White House.)  In 2018 the Committee on STEM education in their report CHARTING A COURSE FOR SUCCESS: AMERICA’S STRATEGY FOR STEM EDUCATION said, “Since 2000, the number of degrees awarded in STEM fields has increased, but labor shortages persist in certain fields requiring STEM degrees.”

Researchers have proposed that one of the biggest reasons for the lack of STEM graduates is the lack of Primary and High School STEM teachers.  Especially high school physics teachers, according to a 2011 report by the US Department of Education only about 46.7% of all high school physics class are taught by a teacher with a degree in the subject.  Furthermore, according to a report from the U.S. Department of Education Office for Civil Rights, only 63% of US high schools offer physics.

Decades into the problem, what do we do to increase the number of people graduating with STEM degrees?  Most of the programs focus on expanding the pipeline getting more people interested in STEM careers at an earlier age.  While these types of programs are essential and vital, especially in the cases of underrepresented groups, I wonder if there might be a better way to increases STEM graduates.

Another way to increase graduation rates would be to increase STEM retention.  Even all these years later, I still remember my first core biology course as an undergraduate.  The professor taught the course in the largest lecture hall on campus; there were over 500 students in that class.  By the end of the core biology sequence, there were less than 250 students left.

According to the National Center for Educational Statistics report STEM in Postsecondary Education: Entrance, Attrition, and Course taking Among 2003−04 Beginning Postsecondary Students, 27.8% of the 2003-04 starting class registered as STEM majors.  According to the same report, 51.7% of the students that started in STEM degrees graduated with a STEM degree. Also, according to the National Center for Educational Statistics, the total student enrolment for fall 2003 was 16,911,481 (https://nces.ed.gov/programs/digest/d13/tables/dt13_303.10.asp retrieved July 27, 20019.)

Using these numbers, the 2003-04 incoming class had 4.7 million registered STEM majors.  By the 5-year graduation mark, the 2003-04 starting class had graduated 2.4 million students with STEM degrees.  Which means the 2003-04 class had lost 2.3 million STEM majors.  If the 2003-04 graduating class had graduated 73% instead of 51.7%, there would have been 1 million more graduating STEM majors.  The same number that Obama set but in half the time and without any changes to the incoming pipeline.

Beyond just increasing the overall number of STEM graduates, increased retention can help in other areas.  For example, from the 2003-04 incoming class, 14.2% of the female students that started as STEM majors left postsecondary education while 32.4% left STEM for other majors. (STEM Attrition: College Students’ Paths Into and Out of STEM Fields Statistical Analysis Report)  Conversely, 23.1% of the Hispanic students that were STEM majors left postsecondary education entirely while 26.4% left STEM majors for other fields. We see similar trends in Black students, 29.3% left higher education without a degree, and 36% left STEM for other majors.  The numbers were lower for Asian students, 9.8% left without a degree, while 22.6% changed to other majors. (STEM Attrition: College Students’ Paths Into and Out of STEM Fields Statistical Analysis Report).

Again, if we could increase the retention rate of these students by 50%, we would add a lot of Female, Hispanic, Black, and Asian STEM majors. The most significant advantage of increasing retention rates to increase the number of STEM graduates is we are already dealing with a group that has an interest in STEM.  Additionally, working on increasing retention forces us to decide if the educational goal for undergraduate students is teaching STEM or sorting STEM students.  After all, it is about time that we remember, not all STEM major wants to get a Ph.D. and become a professor.  At the undergraduate level, we should be teaching STEM students so that they can use their skills to pursue their paths. Thanks for

Listing to My Musings
The Teaching Cyborg