Students, Assignment #6 is another reading assignment, to be submitted as an mp3, as you did with assignment #5. This is the second and final assignment that requires you to send an mp3, and is worth 10 points. (For your information, there are only two more assignments after this, another 10 point assignment and a final 20 point assignment, and that will finish the course.)
This is the part that you have to record. It is about Griffith's Transformation Experiment, so you should know the background by now:
Griffith was interested in the origins of the different strains of S. pneumonia and why some types were virulent, whereas others were not. He observed that small amounts of living type IIIS bacteria injected into mice caused the mice to develop pneumonia and die; on autopsy, he found large amounts of type IIIS bacteria in the blood of the mice (Figure 4.2). When Griffith injected type IIR bacteria into mice, the mice lived, and no bacteria were recovered from their blood. Griffith knew that boiling killed all the bacteria and destroyed their virulence; when he injected large amounts of heat- killed type IIIS bacteria into mice, the mice lived and no type IIIS bacteria were recovered from their blood.
The results of these experiments were not unusual. However, Griffith got a surprise when he infected his mice with a small amount of living type IIR bacteria, along with a large amount of heat-killed type IIIS bacteria. Because both the type IIR bacteria and the heat-killed type IIIS bacteria were non-virulent, he expected these mice to live. Surprisingly, 5 days after the injections, the mice became infected with pneumonia and died (Figure 4.2). When Griffith examined blood from the hearts of these mice, he observed live type IIIS bacteria. Furthermore, these bacteria retained their type IIIS characteristics through several generations; so the infectivity was heritable.
As with assignment #5, be careful with the blendings that I went through in that video, and also be careful with the gaps that you should leave between sentences and places with commas and brackets. Regarding pronunciation, 'III' is '3,' so 'type IIIS' is 'type 3S'. (These are Roman numerals.)
The original open source document for this can be found here.
I am available during the usual tutorial time on Friday. Text me if you want to Zoom.