Biology 446 - Unsolved Problems in Cell Biology - Fall 2020

Meets Monday, Wednesday and Friday, 10:40 AM - 11:30 AM, online.

Albert Harris:

Dr. Harris will not have in-person office hours this semester, but can be reached by e-mail, or on zoom after each class.


Reading for the first week:

Monday, August 10: Philosophy of Science Assignment: Please read this web page.

Wednesday, August 12: Assignment: Read the book "The Double Helix" by James Watson.

Lecture notes for Wednesday, August 12

Friday, August 14: Continue discussing the lessons of Watson's autobiography.


James Watson mentions that he was stimulated to go into science by reading the book "Microbe Hunters" when he was a boy. This same book is credited by every scientific biography I have read, and it also stimulated me when I read it at about age 10.

There is a YouTube video called "Paul De Kruif: The Microbe Hunter and Author" presented by John Lehman, who is a Professor and administrator at ECU medical school. This is nearly an hour long, and is not required, but you may find it interesting.
"Paul De Kruif: The Microbe Hunter and Author"

Please do read the article at this URL:

From the Wikipedia article about about "Microbe Hunters":

"...Paul de Kruif... 1926 book, Microbe Hunters.. a bestseller for a lengthy period... has remained high on lists of recommended reading for science and inspiration for many aspiring physicians and scientists."

This entire book is posted on the web, but is NOT assigned reading for this course:


Another book worth reading, but not required, is the novel "Arrowsmith" by Sinclair Lewis.
You can get the entire text on line here.

Quotes from the Wikipedia article about the novel "Arrowsmith":

"Arrowsmith is arguably the earliest major novel to deal with the culture of science."
"This novel has been inspirational for several generations of pre-medical and medical students."
"Professional jealousy, institutional pressures, greed, stupidity, and negligence... also tireless dedication, and respect for the scientific method and intellectual honesty."


Reading for Wednesday, August 19: Gastric Ulcers and Helicobacter pylori
Please read this web page and look at the links.


Reading for Monday, August 24: Immunology and Autoimmune Diseases
Please read the following web page. We will continue the discussion of autoimmune diseases over several classes.

More information on multiple sclerosis.
Summary of facts about MS, and some questions to think about.
Current treatments for MS - NOT cures.


September 2: Lecture notes on macrophages


September 9-23: Notes on cartilage and bone formation
This link takes you to a page with several more sets of notes.

September 16: particle transport by cell membranes.
This is one aspect of cell traction. This topic is continued in the notes on cell locomotion.

September 25: Retraction fibers.

September 28-30 Locomotion of amoebae and tissue cells.

October 2 Contact inhibition

October 2 Abnormalities of cancer cells [posted October 4th]

October 5 Cell sorting

October 7 Sponge cell rearrangements

October 9 Formation of blood vessels

October 9 Blockage of arteries

The illustrations of normal arteries and veins, and an atherosclerotic artery, were shown in class on October 9th. Some additional material is included in these notes, in case you are interested in further reading on this topic.

October 9 optional reading on formation of arterial networks

October 12 Making tubes, rearrangement rather than "growth"

More on tubes, and a discussion of why eyeballs are spherical [ pdf file]

October 14-19 Chemotaxis

October 21 Regulative development, and scaling; the Driesch phenomenon

October 21 The Roux "hot needle" experiment

October 23-30 Several classes in which we discussed the paper by Dr. Harris, published in 2018, "The Need for a Concept of Shape Homeostasis"


The Nardi & Stocum phenomenon of limb regeneration

October 30 Hox genes
This topic was also discussed in some later classes.

October 30 Gradients that don't involve diffusion

November 2 Neural connections in the eye

November 4 and 6 Positional information and grafting experiments:
Lewis Wolpert, Susan Bryant, and others.

November 9 lecture notes, pdf file

November 9 More on regulative vs. mosaic development and other topics.

November 11 lecture notes, pdf file

More on D'Arcy Thompson, including links to his book online, and more on tensor variables

November 13 lecture notes, pdf file
These notes were updated at 11 am on November 14th, and now include a video link. Please watch it.

November 16 lecture notes, pdf file



There will be a term paper for this course, which will be due by November 16th (the last class of the semester). There will be two options:

You can write an "erroneous paper report" similar to what was done in previous years of Unsolved Problems. Here are the revised instructions so that you won't need to go to the library.

The other option is somewhat more flexible and will encourage you to look for conceptual patterns in the historical development of cell biology and genetics.

The target length for either paper is about 6 pages double-spaced.

You should include a bibliography showing the main sources that you used. For the erroneous paper report, also either include a copy of the published paper that you are discussing, or e-mail it to Dr. Harris as a pdf file.

Please submit your paper on Sakai, preferably as a Word document or pdf file.


FINAL EXAM Monday, November 23, 8:00 AM - 11:00 AM

The final will be during the same 3 hour period that the University requires, but it will be an open book exam. You can use your notes and the course lecture notes and web pages. But please don't use any other web pages, nor any books, during the exam. The questions will be posted on Sakai and also on the class web site when the exam begins. Please submit your answers on Sakai.

The exam will consist of ten questions from the 50+ review questions that are posted on below from which you should answer your choice of any six questions. If each of your six answers, by itself, doesn't amount to at least two double-spaced typed pages, then you are probably not answering in enough detail or depth.

Update: In exam papers from past years, most students' submissions were about 8 to 12 pages long if typed double-spaced. A few good ones had only one page for each question, but were very concisely written. In other words, don't panic and don't add unnecessary padding to your answer; just think and write clearly.

It is OK to discuss the questions with any other members to the class prior to the exam, but please don't just copy their outlines. Your own answer will be better. (But please don't ask faculty members, graduate students or others, until after the exam. I am willing to make hints or suggestions, or to clarify the questions, but never simply to answer them.)

{I solemnly promise to be fair in grading conclusions that I disagree with at least as favorably as I grade answers that happen to match my current opinions. In other words, please don't try to guess what I believe, and argue in favor of it. Strategically, you would be better off to present well-argued opinions that are different from mine. Seeing questions from different points of view are what this course is all about. A. H.}