Shanghai dogs are very special!

There are many dogs in ShanghaiXuhui JTU campus

Hypothesis ：Shanghai dogs can read 汉字 (and obey orders)

Result ：The clever dog 狗 recognized the label 肉 and ignored the box labeled 菜Conclusion: At JTU even the dogs are clever

What was good?

Any problems?

What should we learn?

What was good?

Good observation

Great idea!

Any problems?

鬣狗 hyenas are not dogs

How can you find out whether the bacterium that is growing in your flask is the correct one?

老托的故事 I have seen many scientists wasting time because they failed to recognize contaminants.

Any problems?

Living things have several

senses to ‘read’ the

environment

List all the senses you know, and the organisms where they are most important. Start with bacteria, give examples.Try to explain without using the dictionary

12

3

4

5

1 12

2 2 2

If you repeat an experiment, make sure that it is a true, independent repeat

Does a specific mutation increase antibiotic production?Wild-type strain 0

Mutant strain 1 Mutant strain 2Clonal copy of 1

Gene replacements to generate identical mutations

mg ml-1A B C D E F G H I K L M

Measuring antibiotic production (bioassay, LC)

Growing the bacteria (culture broth/medium, flask/fermenter)

1. Which values will be most similar (small SD, standard deviation)?2. Which measurements represent independent repeats?3. The 3 mutant strains should be the same; why could we get very

different measurements?

Group 1 Group 2

• The values from Group 1 and Group 2 could be very different if one of them had suffered an additional spontaneous mutation.

• Additional spontaneous mutations are common if a gene replacement causes the cells to grow slowly because Compensatory mutations may make the strain fitter.

• All the values in Group 1 are dependent on each other because they all go back to mutant 1

• Only measurements from Group 1 measurements from Group 2 qualify as independent repeats