Let high school students appreciate the beauty of life science

1 Show the mysterious beauty of life phenomenon

In the world of life, there are countless interesting stories and endless mysteries to explore. Teachers must have a far-reaching vision to select, screen and integrate the complicated life phenomena, fully tap the inherent charm and deep value of various resources, and consciously create situations that are in step with the changes in students' psychological needs. Touch the heartstrings of students, let students deeply feel "life is wonderful", induce learning interest, and promote their more active, more in-depth thinking.

For example, why "what you sow, what you reap"? The inheritance of life is the most complex, the most vast, the most difficult to understand, and the temptation of human tireless to explore the profound topic. For more than 100 years, from Mendel's pea experiment, to the transformation experiment of Diplococcus pneumoniae, to the infection experiment of T2 phage, to Morgan's fruit fly experiment, when people found that DNA is the main genetic material of organisms, genes are the basic unit of biological heredity, it is how happy! After the establishment of Watson and Crick's double-helix structure model of DNA molecules, the establishment of 64 genetic codons, and the implementation of the HGP program, people further realized that the location and function of genes are difficult to determine, and the complex structure and function of organisms are not only determined by genes. Is also determined by the existence of a large number of non-coding information and non-coding genes in the genome, where is the sunflower book of genetic language?

When teaching stem cells, I told the children the story of the Berlin Patient. Timothy Ray Brown, an American leukemia patient who also had AIDS, was almost on the verge of death. In 2007, he traveled to Berlin, Germany, and found Dr. Huth, who immediately made a decision: a bone marrow stem cell transplant to treat leukemia first. Unexpectedly, the transplant not only cured the leukemia known as the "Berlin patient", but also cured his AIDS inadvertently, denying the cruel reality that AIDS cannot be cured. Is this a rare case or is it common? Is it replicable or impossible to reproduce? What is the reason? At this time the class is silent, the students' eyes are bright!

There are also many questions: Why are small cell structures, even prokaryotic cells, so difficult to imitate artificially? What causes photosynthetic carbon assimilation in higher plants to have C3, C4 and sedum metabolism pathways? Is it true that language centers exist only in the human cerebral cortex? Do other animals have languages that humans can't see or understand? Is Darwin's theory of natural selection outdated? What explains the Cambrian explosion? The higher the evolutionary status of the organism, the more adaptive... I tell my students that the endless mysteries of the life sciences cannot be fully explained now, leaving you to straighten these question marks into exclamation points in the future.

When students' interest and enthusiasm for the mysteries of life are transformed into permanent interests and aspirations, the seeds of science are quietly planted, and it is likely to sprout, grow, blossom and bear fruit when students construct their future lives.

2. Show the harmonious beauty of life theory

Science is the reflection of law, and law is the core of beauty. For organisms, this law is unity, adaptation, competition, and evolution. In a sense, the law of life phenomena is connected with beauty.

For example, photosynthesis provides the material basis for the survival and development of humans and the entire living world, and is the most important biochemical reaction on Earth. When teaching the "photosynthesis" of plants, I specially picked more than a dozen leafy branches of different plants from the biological garden and geographical garden of the school for students to observe carefully. Whether the arrangement of leaves on the stem is alternate, opposite or whorled, they do not block each other from top to bottom, forming a Mosaic arrangement, so that each leaf can receive sufficient sunlight, and each is beautiful. beauty represents itself with diversity and integrity. The students were amazed by this naturally formed Mosaic of leaves and its rationality, and deeply felt that the survival of organisms and the continuation of the race were inseparable from the environment, and the survival of the fittest would otherwise be eliminated by nature.

For example, in 1894 Fischer proposed the lockkey theory of enzyme action, a key corresponds to a lock. This theory has many implications for our understanding of biological characteristics. In high school biology alone, there are as many as six or seven specific combinations involving "lock and key", such as: membrane carriers and transporters, hormones and target cells, antigens and antibodies, tRNA and mRNA, mutualism, etc., everywhere. It is this law of specificity, similar to the "lock and key theory", that makes life activities more orderly and efficient. Take the three basic laws of heredity as an example, from the separation behavior entry of a pair of alleles in the formation of gametes, to the free combination behavior deduction of non-alleles on two or more pairs of non-homologous chromosomes, and then to the linkage behavior supplement of different genes on the same chromosome, layer by layer, from shallow to deep, integrated!