6.3 Defense Against Infectious Disease

If you like the resources here and the work of Hope HIV, I encourage you to make a donation here.


This is a brilliant TED Talk by Bonnie Bassler on bacteria and how we interact with them:

Click here for the link to AHL content.


Here are some very clear clips for the immune responses to infection, starting with a really well done explanation of Burnet’s Nobel-winning clonal selection theory:

If you like that, check out some more of the videos from the Walter and Eliza Hall Institute of Medical Research.

Try this animation and quiz: McGraw Hill Online Centre

And another Nobel-winner, the cellular response from CancerResearch.org


Phagocytosis in action:

Neutrophil (phagocyte) chasing a bacterium:

The humoral, though not funny, response – from the LifeWire

How does the leukocyte know where to go? Chemotaxis – from Wisc-online


Once you’re sure of how it all works, can you narrate this medical animation?


And for another of the body’s defenses: Natural Killer Cells


Loads more links to clips at North Harris College.



Case Study: Newborn baby ‘cured’ of HIV with rapid detection and ARV treatment. Great introduction to the topic from the New York Times.

Elizabeth Pisani discusses rational behaviour in HIV infection, with lots of Indonesia references:

Hans Rosling, my hero, explodes the Africa=HIV myth using real stats:

90-day time-lapse of a woman on modern anti-AIDS medication:

Could the design of a condom improve HIV prevention? Here is a South African company who hope so: Pronto Condoms. For  a video of how it works (on a plastic model), click here.

Mosaic Science Magazine talks to Françoise Barré-Sinoussi about how she identified HIV as the cause of AIDS, her receipt of the Nobel Prize, and the latest efforts to prevent, treat and manage HIV. [Photo Credit: CC-BY: Ben Gilbert/Wellcome Images]. Click to read.


Antibiotics & Resistance

This is a scary graph. Read this article from Wired and see if you can work out why.

New Antibiotics - from Wired magazine

New Antibiotics – from Wired magazine

And another one from Wired: “Superbugs found in New Delhi’s water and sewage,” which claims that antibiotic resitant genes (NDM-1 enzyme) have appeared in Vibrio cholerae.


So what could happen (and what has in the past) when there is a pandemic? This enlightening BBC Horizon documentary sheds a little light. Get comfortable:

Key terms: immune, macrophage, phagoctosis, leukocyte, lymphocyte, antibody, antigen, epitope, specificity, B-cell, clone cell, clonal selection, immunity, antibiotics, virus, bacteria, fungi, protozoa, pathogen, challenge, response, HIV, AIDS, mucous membranes.

  1. Hey Mr. Taylor! I realized that in your “Defense Against Infectious Disease” slideshow you first claim that viruses have DNA (slide #6) and then you state that they do not have DNA, but only RNA (slide #12). This is rather confusing..

    Love your slideshows though!

  2. Thank you!!! Your slideshows are AMAZING!!!!

  3. Great slides and great website! This is my first year teaching IB biology and your materials have been very very helpful!!

    Just one nitpick: The statement that diseases can be pathogenic or non-pathogenic I think is confusing. Translated this would mean diseases can be disease causing or not disease causing. These terms are usually used with respect to organisms, e.g., pathogenic bacteria or non-pathogenic bacteria, but could be for other disease generating (pathogenic) processes. For instance, heart disease is usually not caused by a pathogenic bacteria, but one might say it can be caused by a pathogenic diet or pathogenic lifestyle. I think the distinction you are making in the “Pathogenic vs. non-pathogenic?” slides is actually “infectious or non-infectious?”

    • Hi Jeff,

      Thanks for the message and for the information – thinking about it carefully, I agree with you. I’ll pull out those slides, as they didn’t do much to help in this last teaching cycle. This kind of peer-editing is a huge advantage of putting all this stuff online – we all get something out of it.

      Thanks, and good luck!


  4. Charlie Cuccherini

    Hello Mr. Taylor

    I’m a first year IB Biology teacher and I was looking for some interesting ideas to use as a Data Collection and Processing internal assessment. Would you be willing to send me any ideas you may have or helpful resources?
    Thank you for posting all of these resources by the way. It has truly improved my ability to present difficult topics to my students this year.

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