Streptomyces链霉菌属

Spontaneous mutations in E. coli (blue = -galactosidase activity

Antirrhinum, Snapdragon 龙头花Somatic mutations are very frequent at

low temperature because of a transposon

jumping out of a flower color gene

Picture 400230 pixels (small)

Tif 300 kb 70 kbLZW JPG medium quality 26 kb

High contrast shows JPG artifacts ‘dirty ‘ image

Tif+LZW compression70 kb

PNG, automatic compression55 kb

Clean pictures without artifacts;

• pictures can be re-edited

Gif (indexed colour)14 kbsharp lines, smallest files, bad for color gradients

JPG highest quality70 kblarge, almost clean file

For smallest clean line drawings:

avoid color gradients, save as Gif

Jpg medium quality 25 kb dirty Tif+LZW 70 kb clean

Gif 14 kb gradient artifact, clean lines JPG max. quality 70 kb clean, gradient OK