Botany - B.E. Yakubenko 2017

Introduction

Botany as a science, its subject matter, and objectives. Botany is a comprehensive science of plants, encompassing their Structure, vital activity, Organization, development, diversity, and global distribution. The main goal of botany is to study the fundamental regularities of plant structure, identify floristic and coenotic diversity, and examine plant-environment interactions and their mutual impacts. Comprehending plants in all manifestations of their life activity enables humanity to learn how to manage plant organisms, obtain the maximum yield of essential plant-derived products, and properly understand the complex biological processes occurring in nature.

The intensive development of science and advanced technological equipment of production present botany with new challenges driven by contemporary achievements. The Development of Electron Cell/15.html">Microscopy has provided a means to delve into the fine Structure of Plant Cells and their Organelles, leading to a deeper understanding of such vital processes as Photosynthesis, Respiration, and METABOLISM/35.html">Protein Biosynthesis. Electron microscopy has helped elucidate The structure of the Cell Nucleus, prove its role in the transmission of hereditary traits, and uncover the material basis of the Gene. New directions in plant Taxonomy, ecology, and geography are emerging, allowing for a deeper insight into plant nature, origin, and evolution.

In modern conditions, predictions regarding the dynamics of flora and vegetation in the face of global climate change, excessive anthropogenic pressure, and declining biodiversity are particularly pressing. All these contemporary challenges require creative specialists with a profound understanding of botany and related biological sciences.

Botany is one of the oldest and most enduring biological sciences, with roots extending back to the 4th century BCE, since which a vast array of diverse botanical knowledge has accumulated. At the same time, it remains a young science, as the advancement of experimental research continuously deepens our understanding of plant Structure and Life activity, unraveling the yet unknown mysteries of the plant Organism.

MAIN STAGES OF plant world evolution. According to paleontological evidence, the first living organisms appeared about 3 billion years ago. These were primitive unicellular creatures that spread throughout the World Ocean, which scientists refer to as flagellates.

According to the Geological Time Scale compiled by geologists and paleontologists, the entire History of the Development of the organic world is divided into the following eras: Archean, Proterozoic, Paleozoic, Mesozoic, and Cenozoic. The first organic life forms arose as early as the Archean era, which lasted for about one billion years; these were likely various chemotrophic Bacteria. In the Proterozoic era, lasting over 2.5 billion years, the first phototrophic organisms emerged, possibly blue-green or even multicellular red Algae. In addition to multicellularity and photosynthesis, a primitive sexual process originated during this era. These aromorphoses provided a powerful impetus for the further development of the PLANT AND ANIMAL kingdoms following The formation of Earth's oxygen envelope.

The Paleozoic era lasted for about 350 million years and is subdivided into the Cambrian, Ordovician, Silurian, Devonian, Carboniferous, and Permian periods.

In Cambrian seas, unicellular and multicellular algae became widespread. Land may have emerged during this period, but the definitive migration of plants to land took place in the Ordovician period and was firmly established in the Silurian. Terrestrial plants settled primarily in tidal zones; according to paleontological remains, these were organisms of very primitive structure, possessing leafless axial Organs known as telomes that branched dichotomously and bore sporangia at their tips. They were named psilophytes or rhyniophytes. These plants gave rise to the group of Water/56.html">LOWER SPORE PLANTS—clubmosses, horsetails, and ferns—which massively colonized the land during the Devonian period. The terrestrial lifestyle led to the refinement of plant organ structures and The Emergence of their diversity.

The Carboniferous period saw the appearance of tree-like forms of spore plants; majestic arboreal horsetails, ferns, and clubmosses formed lush forests along the shores of water bodies. However, mountain-building processes causing land transgression at the end of the Carboniferous destroyed this arboreal flora. Trees fell to the bottoms of water bodies, were covered by sediment, and fossilized over time, eventually forming coal deposits, particularly in the Donbas region. To this day, only herbaceous forms of lower spore plants have survived.

The Permian period was characterized by a drier climate, and spore plants could no longer compete with the more advanced seed plants. During this time, the first seed plants—gymnosperms—emerged, whose flourishing and spread occurred in the subsequent Mesozoic era. The Mesozoic era lasted for over 180 million years and is divided into three periods: Triassic, Jurassic, and Cretaceous. The first two periods were characterized by the extinction of primitive Permian gymnosperms and the flourishing of more advanced gymnosperm forms. The Cretaceous period created the conditions for the emergence of flowering, or angiosperm, plants. Thanks to the perfected structure of vegetative organs and the appearance of a new organ—the flower, within which Fertilization processes took place—angiosperms spread across the globe in a very short time and occupied practically all ecological niches: mountains and valleys, rivers and other water bodies, becoming the dominant group.

The Cenozoic era has lasted for over 67 million years and is the era of modern life; it is divided into three periods: Paleogene, Neogene, and Quaternary (Anthropogene).

The Paleogene and the beginning of the Neogene were characterized by the flourishing of tropical and subtropical vegetation; for instance, forests of magnolia, laurel, and cypress flourished in the territory of modern Ukrainian Polissya. However, at the end of the Neogene, a major glaciation occurred, and glaciers moving from north to south destroyed the thermophilic flora. Gradually, during the Quaternary period, the modern flora with its characteristic zonal vegetation was formed.

The Role of plants in the biosphere and human life. The role of plants in the biosphere can hardly be overestimated. In green plants, thanks to the presence of green pigments called chlorophylls, a unique process known as photosynthesis takes place. As a result of photosynthesis, plants synthesize Organic compounds from inorganic substances (water and carbon dioxide) driven by solar energy. Photosynthesis converts solar energy into the energy of chemical bonds. The solar energy captured by plants is tens of times greater than that utilized by humans in daily life and industry. During photosynthesis, oxygen is released into the atmosphere, which is essential for the respiration of almost All living organisms. Life in the diversity we observe today has become possible solely due to photosynthesis.

Dead organic plant residues, through mineralization processes, return to the soil, thereby ensuring its fertility.

Plants serve as a food source for humans and animals, as well as raw Materials for Processing to obtain not only fodder and food products, but also raw materials for medicine and other industrial sectors, such as textiles, Dyes, vegetable oils, spices, and more. Ukraine possesses vast areas of food crops, satisfying the food needs of its domestic population while also exporting wheat, corn, barley, sunflower oil, and other commodities.

Plants perform soil-protective and water-regulating Functions, safeguarding the soil against water and wind erosion. Vegetation is the foundation for preserving and enhancing biodiversity and maintaining ecological equilibrium in the biosphere. Plants also possess aesthetic value; they not only adorn our environment but also purify the air in large cities by removing dust and dirt and enriching it with oxygen.

Knowledge of botany is essential for future specialists in plant technology and processing for Practical Application; it contributes to the humanization of education and the intellectual and moral development of the individual.

Branches of botany. As noted earlier, modern botany is a complex of sciences, among which the following stand out:

- Cytology, the science of Plant Cell Structure;

- plant Histology, the science of plant Tissues;

- plant Morphology, the science of the regularities of external plant structure, their formation and development;

- plant anatomy, the science of the Internal Structure of organs and their formation during ontogeny and phylogeny;

- phytocoenology, the science of plant communities, their structure, productivity, changes under The Influence of natural and anthropogenic factors, and vegetation zoning and mapping.

- ecology, the science that studies the regularities of interrelationships between PLANTS AND THEIR environment;

- plant taxonomy, the science that studies plant Classification, the Characteristics of Individual groups, their ORIGIN AND EVOLUTION;

- geography is the science that studies the distribution of plants on Earth;

- paleobotany is the science that studies fossil plants.

All these sciences, represented as separate branches of botany, contribute to a comprehensive Study of the plant world as a whole and of individual plants in particular, with the aim of the fullest possible utilization of plant resources by humans in their daily activities and production.