1: Firstly, Mendel's pea hybridization experiment is introduced.

2. Then Morgan's verification gene is on the chromosome.

3. Griffith and Avery's pneumococcal transformation experiment proved that DNA is genetic material.

4. Watson Crick's DNA molecule double helix structure

Basic information:

Hypothetical o- deductive-method, also known as hypothetical o- deductive-method reasoning, refers to putting forward a hypothesis to explain the problem through reasoning and imagination after asking questions on the basis of observation and analysis, and then reasoning according to the hypothesis, and then testing the conclusion of deductive reasoning through experiments. If the experimental results are consistent with the expected conclusions, the hypothesis is proved to be correct, otherwise, the hypothesis is wrong. This is a scientific method commonly used in modern scientific research.

English name: hypothesis deduction

Mbth: Hypothetico- deduction

Nickname: hypothetical deductive reasoning

Uses: Modern scientific research.

Put forward:

1644, Descartes wrote in the second chapter of Principles of Philosophy: "In view of the great significance of the things studied here, if I assert that I have discovered the truth that others have not discovered, then I may be considered reckless by others-so I would rather not solve this problem, but just put it forward as a hypothesis, which may also be far from the truth. But as long as everything from this assumption is consistent with future experience, I will make great contributions eventually, because at that time this assumption will be as valuable to life as it is truth. " Here, Descartes put forward his own theory. As a speculative hypothesis, he thinks that whether or not to accept his theory depends on whether the conclusions derived from his theory are consistent with empirical facts. If they agree, accept his theory, otherwise, reject his theory. Here, the idea from putting forward hypothesis to experiencing rule to accepting hypothesis is the essence of hypothesis-deduction, which is called a monument in the history of modern scientific methodology.