A story of biologists
mendel
School homepage
Physics and chemistry group home page
Teaching routine
Brief introduction of teaching and research group
The story of scientists
Life and science
Interesting little experiment
Open class teaching plan
Student experiment
The father of modern genetics is the founder of this important biological discipline. 1865 found the genetic certainty rate.
1822 On July 22nd, Mendel was born in a poor peasant family in Austria. His parents are both gardeners. Mendel was influenced by his parents since childhood and loved plants.
At that time, in Europe, schools were run by churches. The school needed teachers, and the local church saw Mendel's diligence and studiousness, so it sent him to the capital Vienna University to study.
After graduating from college, Mendel taught in a middle school run by a local church, teaching natural science. He can concentrate on preparing lessons and teaching seriously, which is very popular with students. 1843, 2 1 year-old Mendel entered the monastery, worked as a science teacher in a nearby high school, and then went to Vienna University for further study. He received a fairly systematic and strict scientific education and training, which laid a solid foundation for later scientific practice. After long-term thinking, Mendel realized that it is more important to understand the mechanism that keeps genetic traits unchanged from generation to generation.
Shortly after Mendel returned to Bruen from Vienna University, he began his pea experiment for eight years. Mendel first got 34 varieties of peas from many seed vendors, and selected 22 varieties for experiments. They all have some stable characters, which can be distinguished from each other, such as tall or short stems, round or wrinkled materials, and gray or white seed coats.
Mendel carefully observed, counted and analyzed the characters and quantity of peas in different generations by artificially cultivating these peas. Using this experimental method requires great patience and rigorous attitude. He loves his research work, and the guests who often visit him point to Doudou and say proudly, "This is my child!" " "
After eight years of hard work, Mendel discovered the basic laws of biological inheritance and obtained the corresponding mathematical relationship. People call his discovery "Mendel's first law" and "Mendel's second rate" respectively, which reveals the basic law of biological genetic mystery.
When Mendel started experimenting with peas, Darwin's theory of evolution had just come out. He studied Darwin's works carefully and absorbed rich nutrition from them. Among Mendel's relics preserved to this day, there are several Darwin's works with Mendel's handwriting on them, which shows his concern for Darwin and his works.
At first, Mendel's pea experiment was not to explore genetic laws. His original intention was to obtain excellent varieties, but during the experiment, he gradually shifted his focus to exploring genetic laws. In addition to peas, Mendel has done a lot of similar research on other plants, including corn, violets and mirabilis jalapa, to prove that the genetic laws he discovered are applicable to most plants.
It is difficult to observe and discover the genetic law from the overall form and behavior of organisms, but it is easy to observe from individual traits, which is also the reason for the long-term confusion in the scientific community. Mendel not only inspects the whole organism, but also pays attention to its individual characters, which is one of the important differences between him and his predecessors. Mendel's experimental materials are also very scientific. Because pea is a self-pollinating plant, its variety is stable, easy to plant and separate, and it is counted one by one, which provides favorable conditions for him to discover the genetic law.
Mendel knew that his discovery was of epoch-making significance, but in order to improve it, he carefully repeated the experiment for many years. 1865, Mendel read out his research results twice in the conference hall of Bruen Science Association. The participants listened to the report politely and happily for the first time. Mendel briefly introduced the purpose, method and process of the experiment. The one-hour report puzzled the audience.
The second time, Mendel made an in-depth theoretical proof based on experimental data. However, the great Mendel's thoughts and experiments are too advanced. Although most of the participants are members of Bruen Natural Science Association, there are chemists, geologists and zoologists, as well as botanists and algae experts who specialize in biology. However, the audience is not interested in endless numbers and complicated and boring theories. They really can't follow Mendel's thinking. Mendel's secret, told by painstakingly watered peas, has been buried for 35 years.
In his later years, Mendel confidently said to his good friend Geser, a professor of geodesy at Bruen Institute of Advanced Technology, "Look, my time has come." This sentence became a great prophecy. It was not until Mendel's death 16, 34 years after the pea experiment paper was officially published, and 43 years after the pea experiment, the prediction became a reality.
With the cock crowing for the first time in the 20th century, three scholars from three countries independently "rediscovered" Mendel's genetic law. 1900 is an epoch-making year in the history of genetics and even in the history of biological sciences. Since then, genetics has entered the Mendel era.
Today, after the research of several generations of scientists such as Morgan, Avery, hershey and Watson, the problem of biological genetic mechanism that puzzles Mendel has been based on the genetic material DNA.
With scientists deciphering the genetic code, people have a deeper understanding of the genetic mechanism. Now, people have begun to control the genetic mechanism, prevent genetic diseases and synthesize life, which will be more beneficial to human beings. However, all this is related to the name of the monk who devoted himself to science in St. Thomas Cathedral.
The story of Tong Dizhou.
School homepage
Physics and chemistry group home page
Teaching routine
Brief introduction of teaching and research group
The story of scientists
Life and science
Interesting little experiment
Open class teaching plan
Student experiment
Tong Dizhou is a famous biologist and excellent educator in China. Before his death, he served as vice president of China Academy of Sciences and director of Institute of Zoology.
Tong Dizhou was born in a small village in Yinxian County, Zhejiang Province. His family life is very poor. He has no money to go to school, so he has to do some farm work at home and learn some culture from his father. It was not until 17 years old that he entered Ningbo Normal University with the help of his second brother. However, the average score of the first semester exam failed, and the school asked him to drop out of school or be demoted. After Tong Dizhou's repeated requests, the school reluctantly agreed to try it out for half a year. Tong Dizhou vowed to catch up with her grades. Tong Dizhou insisted on tenacious study. Finally, we achieved good results. After entering Fudan University, he studied harder, and by the time he graduated, he had become the high flyers of Biology Department. Tong Dizhou realized that there is no genius in the world, and genius is bought with labor. To climb the peak of biology, you need to work harder.
1930, with the support of relatives and friends, Tong Dizhou crossed the ocean and came to brucellosis, the capital of northern Europe. He studied embryology under the guidance of Professor Blanchett, a famous European biologist. At that time, he found that some overseas students held a contemptuous attitude towards China people and thought that "China people are nationals of weak countries". An international student who lives with him publicly said, "China people are really stupid." Hearing this, Tong Dizhou could no longer hold back his anger and said to the foreigners, "All right, let's have a competition. You represent your country, and I will compare with you on behalf of my country to see who gets the doctorate first. "
Tong Dizhou, who was breathless with anger, wrote his oath in his diary: "China people are not stupid, they should come up with something to win glory for our nation!"
To study embryology, it is often necessary to peel off the egg membrane Once in an experiment, the professor asked the students to try to peel off the membrane of frog eggs. This is a very difficult operation. The frog egg is only the size of a small grain of rice and is tightly wrapped by three layers of soft membrane like protein. Because the egg membrane is thin, the operation can only be performed under a microscope. Many people have failed. As soon as they peel off the egg membrane, they tear the frog eggs apart. Tong Dizhou was the only one who finished the experimental task quietly.
When Professor Blanchere knew this, he specially arranged an observation experiment for all the students to see. The experiment began, and Tong Dizhou walked unhurriedly to the microscope and operated it skillfully. People see him as careful as a clockmaker, as dexterous as an embroidered mother, and as meticulous as a clever surgeon. Under the microscope, he first pricked a small hole in the egg with a steel needle, so the swollen frog egg immediately relaxed and became oblate, and then gently picked both sides with steel tweezers, and the egg membrane of the frog egg fell off the egg smoothly. He does it quickly and neatly.
"It worked! Success! " The students rushed to congratulate, and Professor Blanchett was even more excited. This is a project that he hasn't done for years! Unable to restrain his inner joy, he praised again and again: "Tong Dizhou is really good! How nice of China people! " The success of peeling frog egg membrane in Tong Dizhou shocked the biological community in Europe. Four years later, through the defense, the Belgian Academic Committee decided to award Tong Dizhou a doctorate. At the conference to get the degree, Tong Dizhou said excitedly, "I come from China, and some people say that people in China are stupid. I have obtained a doctorate from your country, which at least shows that China people are never more stupid than others. " The professors present nodded in succession, and some even held out their thumbs. But that foreign student doesn't even have a thesis, let alone a doctor.
1937 when War of Resistance against Japanese Aggression broke out, Tong Dizhou refused to be retained by experts and classmates, and resolutely returned to the disaster-stricken motherland. He came to teach in a village in Yibin, Sichuan. In the intense teaching, I have never forgotten to engage in scientific research. But without scientific instruments, even a microscope, there is no way to continue embryology research. An unexpected discovery brought him hope: they saw an old microscope at a flea market in a small town, but the asking price was too expensive. At that time, the couple had used up all the money in their pockets, and it was not enough to borrow some from others. Finally, they had to pawn their clothes and finally bought back the old microscope.
With a microscope, but without the necessary lighting, it is still impossible to operate. They had to move the microscope outdoors to take advantage of the weak reflection of snow in winter. He forgot the cold and was absorbed in his work. In the hot summer sun, sweating profusely, although the sweat dripped on the mirror and blurred the vision, or the wind blew a small grain of sand into the container and even occupied the whole field of vision ... Tong Dizhou persisted in tackling the problem. Generally speaking, each test data should be repeated once or twice, and he often repeats it five or six times. However, under this humble microscope, in this low hut, Tong Dizhou wrote a series of papers with academic value, which shocked scholars in the field of biology at home and abroad.
From 65438 to 0973, under the cordial care of Premier Zhou, Tong Dizhou and his partners began the study of cytogenetics. In dissecting microscope, he used a glass needle thinner than an embroidery needle to inject the genetic factors in the egg cells of crucian carp into the fertilized eggs of goldfish. Goldfish eggs are not as big as millet. How difficult it is to do such an experiment! However, Tong Dizhou succeeded. As a result, among the hatched young fish, one fish was covered with golden scales and had a single tail like crucian carp, indicating that the genetics of crucian carp played a role in the golden fish eggs. This kind of fish was created by Tong Dizhou, so people call it "giant salamander". Tong Dizhou's experimental results have made great contributions to biology.
1978, Tong Dizhou gloriously joined the China * * * production party. Although he is 76 years old, he still devotes himself to his work with the vigor of a young man. He personally made a scientific research project plan and drew a beautiful blue map. 1979 In March, on the platform of Zhejiang University of Science and Technology, he suddenly felt dizzy and never got sick again. In order to revitalize the scientific cause of the motherland, he practiced his oath: "I am willing to serve the old cow and die for the country!" " "