Griffith's experiments

93

0

HWC

In the late 1920s, Fred Griffith was attempting to develop a vaccine against a bacterium that causes pneumonia. To find out why two strains of the bacteria differed in their deadliness, he injected mice with four different mixtures. Mice injected with R cells remained healthy. When Griffith examined blood samples from these mice, he found no live bacteria. Mice injected with S cells developed pneumonia and died. When Griffith examined blood samples from these mice, he found live S cells. Mice injected with S cells that were killed by exposure to high temperature remained healthy. When Griffith examined blood samples from these mice, he found no live bacteria. Mice injected with a mixture of live R cells and heat-killed S cells developed pneumonia and died. When Griffith examined blood samples from these mice, he found both live R cells and live S cells. Heat killed the S cells but did not destroy their hereditary material. Somehow, that material was transferred from the dead S cells to living R cells.

Share

Embed

Copy and paste this code into your website or blog.

Add To

You must login to add videos to your playlists.

Comments

0 Comments total

to post comments.

No comments have been posted for this video yet.