Botany Module 1 PDF

=Introduction to Plants and Botany= =History and Development of Botany as a field of Science= PLANTS is the general term of the diverse groups of Humans have always been interested in the organisms that exist...

=Introduction to Plants and Botany= =History and Development of Botany as a field of Science= PLANTS is the general term of the diverse groups of Humans have always been interested in the organisms that exist in the kingdom plant life around them, not only because plants are Plantae. inherently fascinating but also because they can typically characterized by serve useful purposes as food and medicine. ○ lack of locomotion (rooted) ○ absence of sensory organs and a Theophrastus nervous system, - The ancient Greek scholar who lived during ○ synthesizes polymers (molecules) the 4th Century B.C. by photosynthesis, and; - was one of the most famous early ○ could reproduce sexually or botanists asexually. - He first studied with Plato then became a can be seen everywhere, when all the basic disciple of Aristotle. He wrote two major requirements of plant growth are available sets of books on plants, and his writings and that includes sunlight, soil (nutrients made him known as the “Father of and mineral) and water. Botany”. There could be some plants that can growth - Out of the 200 botanical treatises the two even without being rooted on soil because books that survived written in Latin were De available nutrients are found in the water causis plantarum (On the causes of and others thrive is extreme environments Plants) and De historia plantarum like a cactus. (Enquiry into Plants). BOTANY Unlike Theophrastus, who classified plants as - branch of biology that deals with the study of trees, shrubs, and herbs, Dioscorides grouped his plants, including their structure, properties, plants under three headings: as aromatic, culinary, and biochemical processes and medicinal. - Also included are plant classification and the study of plant interactions with the Pedaniua Dioscorides environment. The principles and the findings - From 90-40 A.D. he was another Greek of botany have provided the base for such botanist who wrote an encyclopaedia about applied sciences as agriculture, the herbal medicines called De Materia horticulture, and forestry. Medica (“On Medical Substances”). - In his major work, an herbal in Greek, he Agriculture described some 600 kinds of plants, with - is the active production of useful plants comments on their habit of growth and form (crops) or animals in ecosystems that have as well as on their medicinal properties been created by people. - De Materia Medica Horticulture served as an important medicinal - the branch of plant agriculture dealing with guidebook for over 1500 years, until garden crops, generally fruits, vegetables, widespread use of the compound and ornamental plants. The word is derived microscope in the 19th Century. from the Latin hortus, “garden” and colere, “to cultivate”. Cato the Elder, Varro, Virgil, and Columella Forestry - From the 2nd century BCE to the 1st - the management of forested land, together century CE with associated waters and wasteland, - a succession of Roman writers primarily for harvesting timber.  - prepared Latin manuscripts on farming, Robert Hooke (1665) gardening, and fruit growing but showed - he published, under the title Micrographia, little evidence of the spirit of scientific inquiry the results of his microscopic observations for its own sake that was so characteristic of on several plant tissues. Theophrastus. - He is remembered as the coiner of the word “cell,” referring to the cavities he observed in Pliny the Elder thin slices of cork; his observation that living - In the 1st century CE, though no more cells contain sap and other materials too original than his Roman predecessors, often has been forgotten. seemed more industrious as a compiler. - His Historia naturalis—an encyclopaedia of Nehemiah Grew and Marcello Malpighi (1671) 37 volumes, compiled from some 2,000 - founded plant anatomy works representing 146 Roman and 327 - they communicated the results of Greek authors—has 16 volumes devoted to microscopic studies simultaneously to the plants. Royal Society of London, and both later published major treatises. 15th and 16th centuries - many herbals were published with the Stephen Hales (1727) purpose of describing plants useful in - Experimental plant physiology began with medicine. his brilliant work who published his - Written by physicians and medically oriented observations on the movements of water botanists, the earliest herbals were based in plants under the title Vegetable Staticks largely on the work of Dioscorides and to a (1727). lesser extent on Theophrastus, but gradually - His conclusions on the mechanics of water they became the product of original transpiration in plants are still valid, as is his observation. discovery—at the time a startling one—that - The invention of the optical lens during the air contributes something to the materials 16th century and the development of the produced by plants. compound microscope about 1590 opened an era of rich discovery about Joseph Priestley (1774) plants; prior to that time, all observations by - showed that plants exposed to sunlight give necessity had been made with the unaided off oxygen eye. Jan Ingenhousz (1779) 17th Century - demonstrated that plants in the dark give off The botanists of the 17th century turned away carbon dioxide from the earlier emphasis on medical botany and began to describe all plants, including the many Nicolas de Saussure (1804) new ones that were being introduced in large - demonstrated convincingly that plants in numbers from Asia, Africa, and America. sunlight absorb water and carbon dioxide and increase in weight, as had been Gaspard Bauhin reported by Hales nearly a century earlier. - Among the most prominent botanists of this era who for the first time developed, in a 18th century tentative way, many botanical concepts - The widespread use of the microscope by still held as valid. plant morphologists provided a turning point in the 18th century— botany became largely a laboratory science.  - Until the invention of simple lenses and the in a series of new discoveries, new compound microscope, the recognition and concepts, and new fields of botanical classification of plants were, for the most endeavor. part, based on such large morphological aspects of the plant as size, shape, and Present external structure of leaves, roots, and - new technology is used to understand the stems. Such information was also structure of plant cells further, and research supplemented by observations on more is being done on genetic engineering of subjective qualities of plants, such as plants in an attempt to solve the problem of edibility and medicinal uses. world hunger. - Research is also focusing on ecology and Carolus Linnaeus (1753) climate change (ecology itself became a - published his master work, Species separate discipline in the 1940s). Plantarum, which contains careful - The goals of much present-day research descriptions of 6,000 species of plants from include finding ways of producing better all of the parts of the world known at the crops, developing new medicines from time. molecules found in plants, and figuring out - In this work, which is still the basic how best to conserve natural resources reference work for modern plant in a time of population growth and changing taxonomy, Linnaeus established the climate. practice of binomial nomenclature. - Linnaeus for the first time put the =Evolution of plants= contemporary knowledge of plants into an Plant evolution orderly system, with full acknowledgment - the process of biological and organic to past authors, and produced a change within the plant kingdom by which nomenclatural methodology so useful that it the characteristics of plants differ from has not been greatly improved upon. generation to generation. - The application of the concepts of Charles - Understanding of the course of plant Darwin (on evolution) and Gregor Mendel evolution is based on several lines of (on genetics) to plant taxonomy has evidence. The main levels of evolution have provided insights into the process of long been clear from comparisons among evolution and the production of new species. living plants, but the fossil record has been critical in dating evolutionary events and 19th Century revealing extinct intermediates between chlorophyll was discovered, and scientists modern groups, which are separated from began to understand the process of each other by great morphological gaps photosynthesis. (evolutionary changes in many characters). the Austrian monk Gregor Mendel made - Plant evolution has been clarified by advances in understanding genetic cladistic methods for estimating inheritance through his experiments with relationships among both living and fossil pea plants. groups. These methods attempt to reconstruct the branching of evolutionary 20th century lines (phylogeny) by using shared - saw an enormous increase in the rate of evolutionary innovations (for example, growth of research in botany and the presence of a structure not found in other results derived therefrom. groups) as evidence that particular - The combination of more botanists, better organisms are descendants of the same facilities, and new technologies, all with the ancestral lineage (a monophyletic group, or benefit of experience from the past, resulted clade).  Bryophytes - are a group of plant species that reproduce via spores rather than flowers or seeds. Most bryophytes are found in damp environments and consist of three types of non-vascular land plants: the mosses, hornworts, and liverworts Characteristics of Bryophytes 1. Bryophytes are non-vascular land plants. Although they do exhibit specialized structures for water transportation, they are Charophytes devoid of vascular tissue. - are green algae that live predominantly in 2. Bryophytes grow primarily in damp freshwater habitat. environments but can be found growing in - greenish in color, photosynthetic (chlorophyll diverse habitats ranging from deserts, the a and b) and eukaryotic. Its basic features artic, and high elevations. Since bryophytes are due to the chlorophyll (green pigments) do not depend on root structures for nutrient that are abundant in their thylakoids. uptake like vascular plants, they are able to Charophytes are postulated to be the early survive in environments that vascular plants ancestors of embryophytes (land plants). cannot (e.g., on the surface of rocks). Embryophytes are more closely related to 3. All bryophytes have a dominant the charophytes since their structures are gametophyte stage in their life cycle. During more comparable. The charophytes, make this stage, the plant is haploid and the sex up the green algae. As part of this algal organs that produce the gametes are group, the charophytes are greenish in developed. Bryophytes are unique colour. This is due to the abundant compared to many other plant species in chlorophyll (green pigment) inside their cell. that they remain in this stage for long Their cell wall is chiefly made up of periods. cellulose. They store their food reserves as Examples: starch. 1) Liverworts Liverworts (shown below) are extremely small plants characterized by flattened stems and undifferentiated leaves, as well as single-celled rhizoids. Liverworts can be distinguished from other bryophyte species by the presence of membrane-bound oil bodies within their cells, compared to other species which do not contain enclosed lipid bodies. The stoneworts alga Chara gobularis 2) Mosses plants to spread to new habitats. Although seedless - are green, clumpy plants often found in vascular plants have evolved to spread to all types moist environments out of direct sunlight. of habitats, they still depend on water during Mosses are characterized by leaves that are fertilization, as the sperm must swim on a layer of only one cell wide attached to a stem that is moisture to reach the egg. This step-in reproduction used for water and nutrient transportation. explains why ferns and their relatives are more Mosses are able to absorb a substantial abundant in damp environments, including marshes amount of water and have historically been and rainforests. used for insulation, water absorption, and a The seedless vascular plants can be divided source of peat. into three groups: Lycophyta (lycophytes or club mosses), Sphenophyta (horsetails), and Pterophyta (ferns). The third group of seedless vascular plants is probably the most familiar. These are the ferns or pterophytes. Most of us have seen ferns growing on a forest floor or as cut fronds in a flower arrangement. There are about 12,000 species of ferns in existence today, and they are found in tropical and temperate regions. =Seed vascular plants= The term ‘vascular‘ is derived from the Latin word vāsculum, vās, meaning “a container and 3) Hornworts column”; the overall meaning of vascular is a small - are named after the characteristic long vessel. Compactly, the vascular plants are those horn-like sporophyte that develops. In plants that contain vascular tissues such as contrast, the gametophyte form is a flat, xylem(important for transporting water) and phloem green-bodied plant. Most hornworts are (essential for transporting minerals and nutrients). found in damp environments (e.g., tropical The vascular plants include all the seed-containing climates), garden soils, or tree bark. plants, angiosperms (flowering plants), gymnosperms (non-flowering plants). I) Flowering plant - in simple terms is a plant that at some point during its life cycle produces a flower. - A flowering plant is called an angiosperm. It is important to remember that the flower is part of the reproduction cycle. All flowering plants produce seeds. II) Nonflowering plants - are those that never produce a flower. - Some nonflowering plants still produce =Seedless vascular plants= seeds; this type of plant is called a Seedless vascular plants are plants that contain gymnosperm. Conifer trees—pines, for vascular tissue, but do not produce flowers or example—are among the most well- known seeds. In seedless vascular plants, such as ferns gymnosperms. and horsetails, the plants reproduce using haploid, unicellular spores instead of seeds. The spores are very lightweight (unlike many seeds), which allows for their easy dispersion in the wind and for the Plant Morphology Plant morphology (or phytomorphology) is the general term for the study of the morphology (physical form and external structure) of plants. Plant morphology is useful in the identification of plants. Think about the many types of plants you know. Trees, garden flowers, grass, bulbs, cacti, and vines for example. Tremendous diversity is present, but if we examine each of these, we find they all share the same pattern of body organization. With only a few exceptions, the body of every plant is organized in the following simple way. Roots, stems and leaves are the vegetative organs of a plant. By that, we mean that they are responsible for obtaining energy and materials for growth and survival, but they do not carry out sexual reproduction. When the plant is ready to reproduce, reproductive organs develop. The reproductive organs of most ferns are barely distinguishable from vegetative organs. They are basically just foliage leaves that produce spores on their underside. Without turning leaf over to see if it has spores, one will never guess that is not just an ordinary leaf. Reproductive structures are a bit more complex in the seed plants. Conifers make seed cones and pollen cones, angiosperms make flowers.