TOPIC 1INTRODUCTION to Botany.

Introduction to cytology. Cell and its organelles

PLAN OF LECTURE

• 1. The role of plants in nature.• 2. The tasks of botany and methods of study.• 3. Sections of botany.• 4. The importance of studying botany for

agronomy, forestry, etc.• 5. History of the study of cells• 6. Organoids of the cytoplasm

Literature:

V.G. Khrzhanovsky. "Course of general botany" (I-P tom) 1982. M. High School.

• P.M. Zhukovsky "Botany". M. 1982, High School• Suvorov V.V., Voronova I.N.- Botany with the basics of

geobotany. L. Kolos. 1979• Andreeva I.I. Rodman L.S. Botanica.-M .: Kolos, 2005,

P.172-175.• Lotova L.I .Botany: .Morphology and anatomy of higher

plants. Uchebnik.-M .: Kom. Kniga, 2007 with..312-321

• Barabanov B.I. Zaychikova S.G. Botany: training. for universities.

• M.: Publishing center "Academy", 2006-p.82-85• Yakovlev G.P. Chelombitko V.A. Botany: educational for

higher education.• -SPb .: ed.SPhFA, 2003.-129-132 (647 pages.)• Additional literature• . Botany: in 4 tom .:• Publishing house "Academy" 2007, 352 pages.• . Chukhlebova N.S. ,Ledovskaya N.V. and etc.• Botany (cytology, histology, anatomy) Moscow, "Kolos",

2007, 148 p.•

• 1. Plants and animals constitute a single organic world. Plants have many common features with animals and between them it is sometimes difficult to draw a clear boundary. For all living beings, an indispensable condition for existence is a close relationship with the external environment and metabolism.

• The main properties of a living organism are:• 1.Feeing 2. Breathing, 3. Growth,• 4.Development, 5. Irritation,6. Reproduction,

7.Heredity

• Plants eat (assimilate), secrete unnecessary substances (dissimilate), grow, multiply, perceive external irritation and finally die off.

• Assimilation (from Latin Assimilare - to make it look like) is the absorption of nutrients from the external environment and the formation in the body of substances more complex of the simpler ones. Those. - synthesis. The processes of assimilation proceed with the absorption of energy.

• As a result of assimilation, substances are formed from which the living part of the cell, the cytoplasm, the nucleus, plastids, etc., form.

• Dissimilation (from Latin Dissimilare-to do dissimilarity) is the processes of release into the external environment of certain final products of metabolism and the splitting of more complex substances to simpler ones. These processes proceed with the release of energy. The external expression of dissimilation is breathing and fermentation. Assimilation and dissimilation are interrelated, dependent on each other and proceed

• Metabolism is the most characteristic, the most common property of all life. Metabolism is the totality of all chemical processes carried out by the body and ensuring the growth, preservation and reproduction of life.

• The main difference between plants and animals is the way they feed: green plants -autotrophs, animals - heterotrophs

• Autotrophs (from the Greek Autos-sama, trophe-nourishment) are organisms that feed on mineral substances. Organic matter they synthesize independently in the process of their life. Heterotrophs (from the Greek Heteros-other, trophe-food) -organisms that feed on ready-made organic compounds-proteins, fats, carbohydrates, vitamins, etc. These substances in nature have an organic origin. Therefore, animals eat plants or other animals, which in turn are used for food plants. Some colorless plants include fungi and bacteria.

Distinctive features of plant and animal cells

• Photosynthesis is a process of reducing oxidized carbon and is accompanied by the release of free oxygen. The final result of photosynthesis can be schematically represented in the form of an equation:

• 6CO2 + 6H2O = C6H12O6 + 6O2 +674 kcal• By absorbing huge amounts of carbon dioxide,

creating billions of tons of organic matter and releasing colossal amounts of oxygen into the air, green plants radically transform the nature of our planet. Plants are involved in the biogenic circulation of nitrogen, phosphorus, sulfur, which are part of proteins and a number of organic compounds.

• Green plants - the basis of all life on planet Earth, tk. these are the only organisms that can perform the primary synthesis of organic substances and enrich the atmosphere with free oxygen

• Green plants have a unique ability to extract carbon dioxide from the air and with the help of light energy absorbed by the green pigment chlorophyll, connect it with the molecules of water obtained from the soil. As a result of this process, called the photosynthesis (from the Greek photoshine, synthesis-compound), organic substances are created, which are necessary for building their bodies.

• On our planet, green plants play a cosmic role, since they are a transformer of the energy of cosmic radiations, which convert to terrestrial energy-chemical, mechanical, thermal, electric. Without plants life on our planet would be impossible. Plants are an indispensable resource that we use and therefore need its protection.

• From plants, people receive building materials, fiber for fabrics, raw materials for paper, fuel. From plants are extracted medicinal preparations, tanning and coloring substances, rubber, essential oils, various kinds of chemical raw materials, incl. substitutes for oil and its products.

• There are species of plants that bring and huge harm to humans (poisonous and weeds, fungi that cause diseases of plants and animals, etc.)

• 3000 years before the new era, people in India (the Sumerians) believed that the tree gives 10 wonderful things:

OXYGEN,• WATER,• ENERGY,• FOOD,• CLOTHING• WOOD FOR CONSTRUCTION, • DRUG (MEDICINE)• FODDER FOR CATTLE, • FLOWERS• SHADOW• (from the library of the Sumerians)••

• Botany (from the Greek word "botan" - grass, greens) - the science of plants. The task of botany is to study the shape of plants, the structure, the features of growth, development and patterns of distribution across the globe. Botany studies all the manifestations of the vital activity of plants, classifies them, establishes a system of the plant world, on the basis of its evolution

• Modern botany to study the plant world uses a variety of methods: experimental and descriptive. At the beginning of the development of botany as a science, descriptive methods prevailed. In the future, under the influence of the practical needs of human society, experimental methods of study prevail. The development of botany as a science obeys the general laws of knowledge: from simple to complex, from the study of external and accidental to the opening of deep internal laws

• In the course of its development, botany, as a science, has accumulated a large number of facts and various information about plants and has in fact divided into a number of related, independent disciplines:

• The morphology of plants - studies the shape of the body of plants, the structure and development of individual organs and also the evolution of the forms of the plant world and their dependence on the external environment.

• Anatomy of plants - studies the internal structure of plants, the development and characteristics of cells and tissues that make up the plant organism. The anatomy of plants, in turn, is divided into cytology-the science of the cell, embryology-the exploring origin and development of the embryo and histology-the study of plant tissues

• Systematics of plants - classifies groups of plants on the basis of morphological, anatomical and embryological features, and disposes these groups in a particular system, according to their natural relationship and on the basis of the process of evolution of the plant world.

• The physiology of plants - studies the life processes taking place in the plant, in connection with the conditions of their existence

• Biochemistry of plants - investigates chemical substances in plants, the processes of their formation and transformation.

• Geography of plants - studies the patterns of distribution of plants on the earth's surface.

• Ecology of plants - determines the effect on plants of environmental conditions and the ratio of plants to these factors.

• Geobotany - studying plant groups, their species composition and the reasons for its change. In botany, there are a number of private disciplines that comprehensively study individual groups of plants Bacteriology - the science of bacteria, algology - the science of algae, lichenology - about lichens, about fungi - mycology, about mosses - bryology, trees and bushes are studied by dendrology.

• Botany and agronomy are closely related to the common object of study and the general method of work.

• Cotton-growing - the science of cotton, studies its botanical characteristics, requirements for the external environment, features of growth and development.

• Crop production - the science of plants of field crops and ways of their cultivation.

• Vegetable growing - studies vegetable plants, their cultivation.

• Gardening - studying fruit crops.• Potato growing - studies potatoes, features of

its culture, etc.

• Botany is one of the most important bases of plant growing, for the successful cultivation of cultivated plants, agronomists, plant growers, fruit growers, vegetable growers, foresters, etc. should be well aware of the characteristics of their growth, development, structure and the requirement for an external environment, i.e. all that is the subject of botanical science.

• The search for new useful plants, their introduction into the culture, work to increase the productivity of natural pastures and hayfields, phyto-meliorative work and many other activities require the joint work of botanists and agronomists. For the modern stage of the development of botanical science, the application of experimental methods in those areas where the descriptive ones used to dominate, such as in systematics, geobotany, and plant morphology, is characteristic.

• Simultaneously, faces are erased between separate branches of botany. So in systematics, cytological, embryological and biochemical methods of research are increasingly used methods of physiology and biochemistry are used by ecologists and geobotanists, as a result of which a comprehensive science on the physiology of plant communities is created.

• Recently, botanists are increasingly attracted to work on a global scale: the productivity of phytocenoses existing on the earth, their stability and influence on the circulation of substances and the balance of energy. These studies are particularly important in connection with the growing population of the planet and the increasing human impact on nature.

• So according to the International Council of Nature Conservation, based on observations of satellites, every year on the planet 10,000 sq. m. Burn out from a fire. km. forests. Every minute on the globe 20 hectares of natural habitats are destroyed. Many plant species are on the verge of extinction. Considering. that there are no useless plants, and there are plants that have not been studied, one can understand the importance of preserving each on the planet.

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QUESTIONS FOR SELF-CONTROL. • What does the word "assimilation" mean? • What does the word "dissimilation" mean?• Which organisms are autotrophs?• Which organisms are related to heterotrophs?• What role do plants play on Earth?• What is the difference between plants and animals?• What is the cosmic role of plants?• What are the tasks of botany?• What sections of botany do you know?• Methods of studying botany?• Tell us about the importance of studying botany in the study

of agronomical disciplines?• Why should we protect plants and flora?•

• BASIS OF CYTOLOGY• The origin of the science of the cell (cytology) is

attributed to the 60th years of the XVII century.• Cytology - from the Greek. Words cytos - cell,

logos - doctrine. Representations about the cell, its structure and about the smallest organisms appeared in connection with the invention of the microscope. How firmly established this great invention was now made in 1609 by Galileo Galileo.

• R. Hooke owns the honor of discovering the cellular structure of plants; he also used the term "cell" for the first time (cell in the Latin Cellula, from the word cella, which means: room, camera, cell ..)

• The Italian scientist Malpighi (1675) and the English Grew (1682) confirmed the existence of cells in plants. In 1831 the English botanist R. Braun first described the cell nucleus, and in 1839 the scientist Jan Purkinje examined the liquid contents of the cell, calling it "protoplasm.

• The generalization of accumulated facts and his own studies allowed the German zoologist T. Schwann (1838) and the Austrian botanist M. Shleiden (1839) to create a doctrine of the cell and give it universal significance.

• The essence of this theory can be expressed in three basic propositions: 1. The cell is nominated as the basic structural unit of the whole organic nature, both plants and animals. 2. New cells are formed on the basis of old ones, and the formation of the nucleus precedes the appearance of the nucleus. The cells of plants and animals are independent and homologous to each other in their development and are analogous to the work performed - i.e. functionally.

• At present, cytology is the science of the microscopic and submicroscopic structure of organisms, the structure of the cell and its vital activity.

• Modern methods of research allowed scientists to conclude that the cell is the main structural unit of the organic world and is a complex biological system, all parts of which are in constant interaction

• The cell is the basis for the development, structure and life activity of the organisms of animals and plants-unicellular and multicellular. Each cell has three dimensions: height, length and width. The shape of the cells can be very diverse: rectangular, star-shaped, rounded, most often polyhedral of 15 faces, 8 faces of which are hexagons, and the rest are quadrangles. The whole variety of forms can be reduced to two main groups: a) parenchymatic cells, in form approximating polyhedral, length, width and height. Are approximately the same, b) pro-zenhimatic cells, whose length is many times the width.

• The largest parenchyma cells in the angiosperms reach 1 mm or more: cells of succulent fruit, tomato, watermelon, lemon, etc.

• Prozenhymatic cells are much larger: flax fibers, hemp, - reach 20-40 mm, nettle fibers 80 mm.

• The components of the cell can be divided into two groups: a) organelles - living components that together constitute the protoplast, determine the life of the cell, b) protoplast derivatives - the products of the vital activity (metabolism) of the organelles. The wall of the cell also belongs to the latter.

• Organelles are distributed between two important structural complexes: cytoplasm and nucleus.

• The structural system of the cytoplasm consists of:

• Plasma shell: a) plasmalemma - external membrane of the cytoplasm; b) tonoplast -the inner membrane of the cytoplasm.

• Endoplasmic reticulum (reticulum) is a structured part of the mesoplasm.

• Hyaloplasma - (matrix) - electronically microscopically unstructured part of the mesoplasm

• The cytoplasm is a complex heterogeneous structural complex of the cell. It is characterized by signs that define the very concept of "life": movement, growth, nutrition, respiration, irritability, etc.

• The cytoplasm is a necessary "substrate of life" for all living components of the plant cell. Cytoplasm is a non-uniform chemical substance, but rather a very complex system of cell substances.

• The cytoplasm of plant cells contains 75-85% water, 10-20% protein, 2-3% lipid and 1% inorganic substances. The total percentage of proteins can reach 65-70% or more of the dry substance of the cytoplasm.

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• One of the main properties of the cytoplasm of a living cell is its ability to move. For the first time its movement was observed by the botanist B. Corti (1772) and then in 1811 by

• L. Traviranus. These scientists took cytoplasm for cell sap. As the most important component of the cell, the cytoplasm was discovered later.

• The most important property of the cytoplasm is its selective permeability, which means that it is permeable to water and, to a lesser extent, for substances dissolved in it. An exceptional role in the phenomenon of selective permeability belongs to two boundary layers of the cytoplasm -plasmalemma (external cytoplasmicmembrane) and tonoplast (vacuolar membrane).

• The endoplasmic network of EPS is a special organelle of a cell of universal significance. It performs such functions: 1) connection with the nucleus and with adjacent cells through plasmadesmas, 2) absorption of substances and their transportation, 3) participation in synthesis processes. There is an obvious direct relationship between the endoplasmic reticulum and the nuclear envelope.

• Hyaloplasm - called the main, optically homogeneous cytoplasm in which the remaining organelles of the cell and nucleus are located.

• The function of the hyaloplasm is exceptionally great. It is a continuous cellular environment in which all other components of the cell that interact with each other are inlaid, serves as the main backbone for the movement of metabolites of the cell, provides intercellular connections. Regulates the physicochemical and enzymatic bonds between them.

• Ribosomes were discovered in 1955 by T. Pallade. Submicroscopic organelles about 20 mm in diameter. Ribosomes are composed of several ribonucleic acid (RNA) molecules in the form of a helix. RNA ribosomes about 80-90% of the total amount of this acid contained in the cell.

• Ribosomes of some what smaller size are found in mitochondria and plastids. Cytoplasmicribosomes are divided on the availability (ranging in hyaloplasm) and attached to the outside (facing the hyaloplasm) surface of the membranes of the endoplasmic reticulum and the nuclear envelope to the outside

• Ribosomes perform a very important function of synthesizing proteinaceous substances. Scientists have proved that RNA synthesis is carried out in the nucleus.

• For protein synthesis, RNA molecules located in ribosomes are activated by special messenger RNA (mediator) molecules that separate from DNA molecules located in the cell nucleus. Proteins synthesized by ribosomes enter the endoplasmic reticulum and are transported to various parts of the cell

.

• De oxy ribonucleic acid

They are like packs of flat tanks, the walls of which are formed by plasma membranes.

Organic substances temporarily accumulate in dictyosomes or Golgi apparatus, which are then transported to other parts of the cell.

• Mitochondria (chondriosomes) have a special form of short rods 0.5-1 m in diameter and 2-5

m in length. The totality of all mitochondria in the cell is called chondrioma. Mitochondria are able to move in a cell. The number of mitochondria in a cell is on the average 2-2.5 thousand. The specific gravity is slightly higher than the cytoplasm. Therefore, they can be separated by centrifugation. Mitochondria consist mainly of protein substances (60-70%), lipids (25%) and a small amount of RNA and inorganic compounds.

• Mitochondria in the plant organism perform very important functions, being, as it were, the energy centers of the cell. Here, adenosine triphosphate (ATP) is synthesized, due to the energy released during the oxidation of various metabolic products. Synthesized ATP is a kind of energy accumulator.

• Spherosomes are round bodies of a lipid-protein nature. The diameter is 0.5-1 m. They arise from the end blistering of EPS strands and are rich in enzymes necessary for the synthesis of fats. The development of spheroids and the appearance of oil droplets in the cells are a single process.

• Lysosomes - small particles in the cytoplasm d-0.4 . A vacuole containing hydrolytic enzymes occupies a central position in them. Enzymes of lysosomes are involved in the processes of the cleavage of organic substances. Genetically, lysosomes are associated with the Golgi apparatus.

• different metabolic products. Synthesized ATP is a kind of energy accumulator.

• Plastids, they are widely represented in almost all green plants. The process of primary and secondary carbohydrate synthesis is associated with plastids. Plastids are well distinguishable in color, therefore, at the end of the last century, A. Shimper divided them into three groups:

• 1) colorless plastids - leukoplasts,• 2) colored green - chloroplasts,• 3) Red, yellow or yellow-red chromoplasts••

• Chloroplasts are found in all the green parts of the body of the plant. Their shape is round or discoid, the sizes vary from 3 to 10 microns. The body of the chloroplast consists of a protein mass (stroma) pierced by a system of two-membrane lamellae, in which the green pigment chlorophyll and other pigments are concentrated.

• Leukoplasts - colorless plastids are found in the skin, in the cells of the embryo, in the roots, tubers and bulbs of many plants. They have the form of small (1-2 microns) round or discoid bodies. In tubers, rhizomes and seeds of plants the role of leukoplasts is to accumulate a reserve nutrient - secondary starch. Leukoplasts, accumulating starch, were called amyloplast

• Green pigment chlorophyll - a complex organic substance - an ester of two basic chlorophyllinic acid with two alcohols: phytoland methanol. The role of chlorophyll in plant life is great, because with his participation, the process of photosynthesis is carried out, as a result of which simple organic compounds and substances are created from simple inorganic compounds and substances, which form the basis of the body of the plant.

• . In addition to chlorophyll, chloroplasts contain other pigments, orange or yellow, which are classified as carotenoids. This is carotene and xanthophyll. In the leaves of dying in autumn, chlorophyll grains are destroyed and the yellow tones of the corresponding pigments begin to predominate in coloring

• Chromoplast - red-yellow plastids containing pigments of a group of carotenoids. These plastids are found in the vegetative organs of plants, in flowers and fruits. The form of chromoplasts is diverse: they look like rods, disks, triangles, etc. Chromoplasts originate from protoplasts, or chloroplasts, by replacing chlorophyll with carotenoids. The bright coloration of flowers and fruits attracts insects of pollinating flowers and animals that eat fruits that promote the dispersal of plants.

• Different types of plastids are connected by mutual transitions. For example, immature tomato fruits turn red during maturation, which is associated with the transition of chloroplasts to chromoplasts. When exposed part of the growing root of carrots, it turns green. yellow plastids become green. Potato tubers are green in the light, which is associated with the transition of colorless plastids of leukoplasts to green - chloroplasts.

• QUESTIONS FOR SELF-CONTROL.• What is the example of parenchymal cells?• What is the example of prozenhim cells?• To which two groups can the whole variety of cells be reduced?• What is the essence of cell theory?• What membrane of the cytoplasm do you know?• What is the main property of the cytoplasm?• What is the function of ribosomes in a cell?• What is the function of the Golgi apparatus?• What is the function of mitochondria?• 10. What types of plastids do you know?• 11.What are the functions of chloroplasts, leukoplasts?• 12.What pigments are found in chloroplasts and what is their

role?

• THANK YOU FOR YOUR ATTENTION