The theme of the study is
morphology
Morphology is a subject in biology that studies the morphological structure of animals and plants. Before the invention of microscope, morphology was limited to macroscopic observation of animals and plants, such as gross anatomy and comparative anatomy of vertebrates. Comparative anatomy is to study the structural similarities and differences of vertebrates by comparative and historical methods, so as to find out the genetic relationship and historical development of these categories. After the invention of microscope, histology and cytology were established accordingly. With the use of electron microscope, morphology goes deep into the field of ultrastructure. However, the study of morphological structure can not be completely divorced from the study of function, and morphology has already jumped out of the circle of simple description and used various advanced experimental means.
physiology
Physiology is a subject that studies biological functions, and the research method of physiology is mainly experiment. According to the research object, it is divided into plant physiology, animal physiology and bacterial physiology. Plant physiology is established during the development of agricultural production. Physiology can also be divided into cell physiology, organ physiology and individual physiology according to the structural level of organisms. Early plant physiology mostly took seed plants as the research object; Animal physiology is mostly related to medicine, with people, dogs, rabbits and frogs as the research objects; Later, it gradually extended to the physiological research of lower organisms, thus developing comparative physiology.
genetics
It is a subject that studies the inheritance and variation of biological characters and expounds their laws. Genetics is developed under the impetus of breeding practice. 1900, Mendel's genetic law was rediscovered and genetics began to be established. Later, due to the work of T.H. Morgan and others, a complete cytogenetic system was established. Swiss biologist Meshel discovered for the first time that there is a substance with extremely high phosphorus content in the nucleus. Twenty years later, this chemical component was named nucleic acid. Later, through the efforts of many scientists, it was found that there are two kinds of nucleic acids, one is deoxyribonucleic acid, that is, DNA, which has the function of storing and inheriting information, and the other is ribonucleic acid, abbreviated as RNA, which plays an important role in the expression of genetic information. From 65438 to 0953, the molecular structure of genetic material DNA was revealed and genetics went deep into the molecular level. The progress of genome project, the transmission of genetic information from genome and protein group to metabonomics, and the research of cell signal transduction and gene expression regulation network, the concept, vocabulary and principle of systems genetics were put forward and published in Chinese Academy of Sciences 65438-0995. The transmission of genetic information and the regulation mechanism of genes have been gradually understood. Genetics theory and technology are playing an important role in agriculture, industry and clinical medicine practice, and occupy an important position in all branches of biology. Many problems in biology, such as the mechanism of individual development and biological evolution, the formation of species and the concept of population, must be deeply understood by applying the achievements of genetics.
embryology
It is a subject that studies the individual development of organisms, originally belonging to the category of morphology. /kloc-the publication of Darwin's theory of evolution in 859 greatly promoted the study of embryology. /kloc-in the second half of the 9th century, the morphology of embryo development and fertilization process was described in detail and accurately. Since then, animal embryology has developed from observation and description to experimental study of development mechanism, thus establishing experimental embryology. The research on individual development adopts biochemical methods, absorbs the achievements of molecular biology, further analyzes the mechanism of development and character differentiation at the molecular level, and expands the research on development from embryo to the whole life history of organisms, forming developmental biology.
ecology
It is a subject that studies the relationship between organisms, between organisms and between organisms and the environment. The research scope includes individuals, populations, communities, ecosystems and biosphere. Revealing the relevant laws of food chain, productivity, energy flow and material circulation in ecosystem is not only of great theoretical significance, but also closely related to human life. The biosphere is the home of mankind. Human production activities continue to consume natural resources and destroy the natural environment. Especially after entering the 20th century, due to the rapid growth of population and the rapid development of industry, the natural environment has suffered an unprecedented destructive impact. Protecting resources and maintaining ecological balance is an urgent task for mankind at present. Ecology is an important part of environmental science, so it can also be called environmental biology. Human ecology involves human society, which has gone beyond the scope of biology and is related to social science.
biophysics
Biophysics is a subject that studies the structure and function of organisms and the physical and physicochemical processes of life activities with the concepts and methods of physics. Early biophysical research began with bioluminescence, bioelectricity and other issues. Since then, with the development of biology, the emergence of new physical concepts such as quantum physics and information theory, and the use of new technologies such as X-ray diffraction, spectroscopy and spectroscopy, the research scope and level of biophysics have been broadened and deepened. Some important life phenomena, such as the reaction of capturing light energy at the initial moment of photosynthesis, the structure and mechanism of biofilm, are all research topics in biophysics. Crystal structure of biological macromolecules, quantum biology and biological cybernetics also belong to biophysics.
biomathematics
Biomathematics is the product of the combination of mathematics and biology. Its task is to study the mathematical laws of biological problems and life processes by mathematical methods. In the early days, people only used statistics, geometry and some elementary analysis methods to make a static and quantitative analysis of biological phenomena. After the 1920s, people began to build mathematical models to simulate various life processes. Biomathematics plays an important role in various fields of biology such as physiology, genetics, ecology and taxonomy, which makes the research level in these fields improve rapidly. On the other hand, biomathematics itself has developed into an independent discipline in solving biological problems.
A few biological disciplines are divided by methods, such as descriptive embryology, comparative anatomy and experimental morphology. Disciplines classified by methods are often included in the above-mentioned disciplines classified by attributes and types as sub-disciplines at a lower level.
The biological world is a multi-level complex system. In order to reveal the law of a certain level and its relationship with other levels, disciplines divided by levels have emerged and attracted more and more attention.
molecular biology
Molecular biology is a subject that studies the process of life at the molecular level. Its task is to reveal the material basis of various life processes from the structure and function of molecules and the interaction between molecules. One of the main branches of modern molecular biology is molecular genetics, which studies the replication of genetic material, the transmission and expression of genetic information and its regulation.
cytobiology
Cell biology is a subject that studies the process of life at the cellular level. In the early stage, cytology was mainly based on morphological description. After that, cytology absorbed the achievements of molecular biology and went deep into the level of ultrastructure, mainly studying the biological processes such as cell growth, metabolism and inheritance, and cytology developed into cell biology.
Individual biology is a subject that studies the process of life at the individual level. Before the invention of compound microscope, biology mostly focused on individuals and organ systems. To study the individual process, it is necessary to analyze the organ system process, cellular process and molecular process that make up this process. But the individual process is different from the simple addition of organ system process, cell process or molecular process. Individuals have a self-regulation mechanism in this process. Through this mechanism, highly complex organisms are integrated into a highly coordinated unity and respond to the stimulation of external factors with coordinated behavior. Individual biology was established very early and is still very important until now.
Population biology is to study the structure of biological population, the relationship between individuals in the population, the relationship between population and environment, the self-regulation and genetic mechanism of population. Population biology and ecology overlap greatly. In fact, population biology can be said to be a basic part of ecology.
The above is only the main pattern of biological branches at present, and there are more actual disciplines than the above. For example, as humans enter space, cosmic biology is already developing. For another example, with the continuous improvement of experimental accuracy, the requirements for experimental animals are becoming more and more strict, and the research on aseptic biology and ecological biology is also established because of the need. In short, some new disciplines are constantly dividing and some disciplines are moving towards integration. This situation of biological division reflects the extremely rich content of biology and its vigorous development.