Cell and Plant Sciences
Botany is the science about plants. What does botany study?
Botany (plant science) a complex science that studies plants. It comprehensively considers their origin, development, structure (external and internal), classification, distribution on the earth’s surface, ecology (relationships with environmental factors), protection. Like other sciences, botany has its own prehistory. Its origin can be traced from ancient times, when people were just starting to use plants for their practical needs (nutrition, treatment, clothing, housing). For quite a long time, natural scientists were engaged only in the description of plants — their size, color, and characteristics of individual organs. This section of biology was formed in the XVII-XVIII centuries. The first attempts to systematize the plant world became the beginning of the use of the comparative – descriptive method in botany, with the help of which the plants were not only described but also compared by external (morphological) characters. With the invention of the microscope, botany was born, and later, thanks to the intensive development of science and the improvement of microscopic technology, the experimental direction began to dominate.
Plants are a source of more than ten biologically active substances that act on the human and animal body, in particular when consumed in food. Since plants are inalienable in human life, they have become the subject of close study. All plants are divided into 2 large groups: lower plants, or thallus (thalamus); higher plants, or leafy. The lower plants include algae. Higher plants include bryophytes (mosses and liverworts), fern-like (psilophytes, psilots, horsetails and ferns), gymnosperms and angiosperms. Lichens, fungi, and bacteria are studied separately.
Modern plant science is a diversified science that covers a number of sections: plant taxonomy, which is engaged in the classification of plants according to similar general characteristics. It is divided into two parts: floristry and botanical geography. Floristry studies plant communities in a particular area. Botanical geography studies the characteristics of the distribution of plants on the globe.
Plant taxonomy is the main botanical discipline. It divides the whole plant world into separate groups, explains the related and evolutionary relationships between them. This task is a special section of botany – phylogeny.
At first, researchers systematized plants only according to external (morphological) characteristics. Now, their internal features are also used for the taxonomy of plants (structural features of cells: their chemical composition, chromosome apparatus, environmental features).
Plant morphology (which studies the structure of plants) is divided into microscopic morphology and macroscopic morphology (organography). Microscopic morphology studies the structure of cells and tissues of plants, as well as embryology. Macroscopic morphology studies the organs and parts of plants.
We decided to separate some sections of morphology into several disciplines:
- organography (studies plant organs);
- palynology (considers the structure of spores and pollen of plants);
- carpology (deals with the classification of fruits);
- teratology (the subject of study is ugliness and anomalies in the structure of plants);
- plant anatomy, which studies the internal structure of plants;
- plant physiology, which studies the forms of plants during their ontogenesis and phylogenesis, as well as the processes occurring in plants, their causes, patterns and relationship with the environment. It is closely related to taxonomy;
- plant biochemistry, which studies the chemical processes in plants associated with growth and development;
- plant genetics, which studies plant genetic changes that occur with or without human intervention;
- phytocenology, which studies the Earth’s vegetation cover, determines dynamic changes in nature, as well as their dependencies and patterns (vegetation is a combination of all plants in one territory that make up the landscape;
- geobotany, which studies ecosystems, that is, the relationships between plants, animals the world and factors of inanimate nature (the whole complex was called a biogeocenosis);
- plant ecology, which studies plants depending on its habitat and determines ideal conditions for plant life;
- paleobotany, which studies fossil plants in order to determine the history of development.
Botany is also classified according to the objects of study into:
- algology – the science of algae, bryology, which is engaged in the study of mosses and other research on microscopic organisms in the plant world has also been identified as a separate discipline – microbiology;
- phytopathology – deals with plant diseases that can be caused by fungi, viruses or bacteria.
Traditionally, mycology is included in botany – the science of mushrooms (from the middle of the 20th century they were singled out as a separate kingdom), as well as lichenology – the science that studies lichens.
The subject of botany research is plants, their structure, development, family ties, the possibility of their rational economic use.
Objectives of plant science:
- The study of plants to increase their resistance, productivity and endurance;
- Identification of new plant species and their application;
- Determination of the effect of plants on the human body;
- Determination of the role of man in the development and conservation of vegetation of the planet;
- The implementation of the genetic transformation of plants.
Research methods in plant science:
- observation method is used both at the microscopic and macroscopic levels. This method consists in establishing the individuality of the object that is being studied, without artificial interference in its vital processes. The information collected is used for further research;
- comparative method is used to compare the object that is being investigated with similar objects and to classify them, analyzing in detail similar and distinctive features in comparison with forms close to them;
- experimental method is used to study objects or processes in specially created artificial conditions. Unlike the observation method, the experimental method foresees a special intervention of the experimenter in nature, which allows us to establish the consequences of the influence of certain factors on the object of study. The method can be used both in vivo and in the laboratory;
- monitoring is a method of continuous monitoring of the state of individual objects, the course of certain processes;
- modeling is a method of demonstration and research of certain processes, phenomena with the help of their simplified imitation. The method makes it possible to study processes that are difficult or impossible to reproduce experimentally, or directly observe in living nature;
- the statistical method is based on the statistical processing of quantitative material collected as a result of other studies (observations, experiments, modeling), which allows it to comprehensively analyze and establish certain laws.
Cell science – the science of the structure and function of cells
The subject of (cell science) cytology is the cell of multicellular fungi, plants and animals, as well as unicellular organisms (bacteria, unicellular fungi and algae, protozoa). Cytology studies the structure, chemical composition and functions of cells, the functions of intracellular structures, the reproduction and development of cells, the adaptation of cells to environmental conditions. Modern cytology is a complex science. It is very closely connected with other biological sciences: physiology, botany, zoology, physiology, evolutionary doctrine. There is a general and private cytology. The subject of the study of general cytology is the elements common to most cells: their structure, functions, metabolic processes, response to damage and pathological changes, adaptation to environmental conditions.
Clear boundaries between cytology, biochemistry, developmental biology, molecular biology and molecular biophysics have been erased thanks to new methods for studying cell components, the development and improvement of cytochemistry studies, especially enzymes, the use of radioactive isotopes in the study of cell macromolecule synthesis processes, the introduction of electronic cytochemistry methods, and the application for studying localization of individual cell proteins using luminescence analysis of fluorochrome-labeled antibodies, preparative and analytical centrifugation methods. Modern cytology from suto-morphological science was able to develop into an experimental discipline that studies the basic principles of cell activity and, accordingly, the foundations of the life of organisms. Cytological studies are essential in the diagnosis of human and animal diseases.
Thanks to the development of B. Gerdon’s methods of nuclear transplantation into cells, somatic hybridization of cells by H. Harris, J. Barsky and B. Efrussi, it became possible to study the patterns of gene reactivation, to determine the localization of many genes in human chromosomes. It also became possible to approach a solution to a number of practical tasks of medicine and the national economy (the creation of new crops). The method of obtaining stationary antibodies of hybrid cells producing specific antibodies (monoclonal antibodies) has been created by the method of cell hybridization. They are used to identify a number of theoretical issues in microbiology, immunology, and virology.
Due to the multifaceted nature of the problems of cell research, the specificity and variety of methods for its study, there are six main directions in cytology:
- Cytomorphology studies the features of the structural organization of the cell. The main methods of research are various methods of microscopy, both fixed (light-optical, electronic, polarizing), and living cells (dark-field condenser, phase contrast and luminescent microscopy);
- Cytophysiology studies the vital activity of a cell as a single living system, as well as the functioning and interaction of its internal structures. To solve these tasks, they use various experimental techniques, along with methods of cell and tissue culture, micro-filming;
- Cytochemistry examines the molecular organization of a cell and chemical changes during metabolic processes and cell functioning. Cytochemical studies are carried out using light microscopy and electron microscopy methods, methods of ultraviolet and interference microscopy, cytophotometry, and fractional centrifugation;
- Cytogenetics studies the functional and structural and organization of eukaryotic chromosomes;
- Cytoecology examines cell reactions to the influence of environmental factors and mechanisms of adaptation to them;
- Cytopathology studies the pathological processes in the cell.
There are new areas of cytology that are actively developing, such as virus cytopathology, ultrastructural cell pathology, cytopharmacology, oncological cytology, etc.
You can get more information on the topic in cell and plant journals.