REPÚBLICA BOLIVARINA DE VENEZUELA MINISTERIO DEL PODER POPULAR PARA LA EDUCACIÓN
INSTITUTO UNIVERSITARIO POLITECNICO “SANTIAGO MARIÑO” MÈRIDA -EDO- MÈRIDA
Jesus Alberto Peña Gamez ID:23.583.609 Agronomic Enginee October, 2013
Plant kingdom………………………………………………………………………………………………….. Plant Classification: History of Classification Systems……………………………………… Taxonomic Structure. The Classes…………………………………………………………………… Gymnosperms……………………………………………………………………………………………………………. Angiosperms……………………………………………………………………………………….……………………… Monocots and dicots………………………………………………………………………………………………….. Reproduction in Higher Plants……………………………………………………………………………………. Species………………………………………………………………………………………………………………………
PLANT KINGDOM Virtually all other living creatures depend on plants to survive. Through photosynthesis, plants convert energy from sunlight into food stored as carbohydrates. Because animals cannot get energy directly from the sun, they must eat plants (or other animals that have had a vegetarian meal) to survive. Plants also provide the oxygen humans and animals breathe, because plants use carbon dioxide for photosynthesis and release oxygen into the atmosphere. Plants are found on land, in oceans, and in fresh water. They have been on Earth for millions of years. Plants were on Earth before animals and currently number about 260,000 species. Three features distinguish plants from animals: -Plants have chlorophyll, a green pigment necessary for photosynthesis; - Their cell walls are made sturdy by a material called cellulose; and - They are fixed in one place (they donâ€™t move) Plant Classification: History of Classification Systems In order to study the billions of different organisms living on earth, biologists have sorted and classified them based on their similarities and differences. This system of classification is also called a taxonomy and usually features both English and Latin names for the different divisions. All plants are included in one so-called kingdom (Kingdom Plantae), which is then broken down into smaller and smaller divisions based on several characteristics, including: Whether they can circulate fluids (like rainwater) through their bodies or need to absorb them from the moisture that surrounds them; How they reproduce (e.g., by spores or different kinds of seeds); and Their size or stature. The majority of the 260,000 plant species are flowering herbs. To describe all plant species, the following divisions (or phyla) are most commonly used to sort them. The first grouping is made up of plants that are non-vascular; they cannot circulate rainwater through their stems and leaves but must absorb it from the environment that surrounds them. The remaining plant species are all vascular (they have a system for circulating fluids). This larger group is then split into two groups: one that reproduces from spores rather than seeds, and the other that reproduces from seeds.
Non-Vascular Plants Mosses and “allies,” or related species (Bryophyta and allies) Mosses or bryophyta are non-vascular. They are an important foundation plant for the forest ecosystem and they help prevent erosion by carpeting the forest floor. All bryophyte species reproduce by spores not seeds, never have flowers, and are found growing on the ground, on rocks, and on other plants. Originally grouped as a single division or phylum, the 24,000 bryophyte species are now grouped in three divisions: Mosses (Bryophyta), Liverworts (Hepatophyta), and Hornworts (Anthocerotophyta). Also included among the non-vascular plants is Chlorophyta , a kind of fresh-water algae. Vascular Plants with Spores Ferns and allies (Pteridophyta and allies) Unlike mosses, ferns and related species have a vascular system, but like mosses, they reproduce from spores rather than seeds. The ferns are the most plentiful plant division in this group, with 12,000 species. Other divisions (the fern allies) include Club mosses or Lycopods (Lycopodiophyta) with 1,000 species, Horsetails (Equisetophyta) with 40 species, and Whisk ferns (Psilophyta) with 3 species. Vascular Plants with Seeds Conifers and allies (Coniferophyta and allies) Conifers and allies (Coniferophyta and allies) Conifers reproduce from seeds, but unlike plants like blueberry bushes or flowers where the fruit or flower surrounds the seed, conifer seeds (usually cones) are “naked.” In addition to having cones, conifers are trees or shrubs that never have flowers and that have needle-like leaves. Included among conifers are about 600 species including pines, firs, spruces, cedars, junipers, and yew. The conifer allies include three small divisions with fewer than 200 species all together: Ginko (Ginkophyta) made up of a single species, the maidenhair tree; the palm-like Cycads (Cycadophyta), and herb-like plants that bear cones (Gnetophyta) such as Mormon tea. Flowering Plants (Magnoliophyta)
The vast majority of plants (around 230,000) belong to this category, including most trees, shrubs, vines, flowers, fruits, vegetables, and legumes. Plants in this category are also called angiosperms. They differ from conifers because they grow their seeds inside an ovary, which is embedded in a flower or fruit Taxonomic Structure. The Classes. Taxonomy, a fundamental life science discipline, deals with biological complexity and diversity to define elements, create order, provide linking symbols (scientific names), and identification aids (taxonomic keys). This produces hierarchical systems of classification (taxonomy is also known as 'systematics') that serve as a structural foundation, used by the scientific community and the general public, that provides an infrastructure for all information relating to the group of organism in question. It is important to keep in mind that hierarchical classification systems are made up of nested sets (taxa) that relate to one another by structural features that mark genetic/genomic relationship. Thus, the classification system carries, in its internal structure, information about a given element (taxon) as it is positioned with the matrix of affinities or differences represented by the classification system. It should be noted that the structure of modern flowering plant classification systems is based phylogenetic patterns, i.e., taxa represent lineages that share a common evolutionary history. Thus, the foundation of this course - and essentially all life science courses - is based in modern evolutionary theory. Notions advanced by "creation science" are not relevant to the material presented in Botany 201. Flowering plant lineages or taxa are defined by shared structural features or key characteristics. Since plants express many structural characteristics, it is important to be able to recognize the sub-set of features that define, or circumscribe (to draw a line around) taxa at various levels or ranks in the hierarchy of a classification system. We will spend much time during the course of this semester developing a recognition 'eye' for flowering plant family identification, i.e., a focus on relevant variables or key characters that circumscribe major angiosperm families. We will spend some time with ranks above the Family level (Classes, subclasses, Orders) and taxa that occur within the Family (Genera, Species), but the Family will be a central focus, especially about 40 'target' Families.
As indicated above, the angiosperms (rank = Phylum or Division, technical name = Magnoliophyta) are a large, complex group of organisms. The group includes over 200, 000 species with over 20, 000 present in the North American flora, over 5,000 in the Texas flora, and over 1, 000 in the local (Brazos and adjacent counties) flora. Our local Spring flora is especially diverse and, to those with no experience, training, or 'eye' for the flowering plants, the Spring flora presents a complex, chaotic assemblage of many different 'kinds' of plants. This is represented by the image below which was taken from a native prairie site (Old Baylor) in Washington County near Independence, Texas. The primary mission of Botany 201 is to provide a foundation for the student to develop an 'eye' for the flowering plants, i.e., a perspective - based on key characters - that allows resolution of patterns that connect 'kinds' (Species) to genera and Genera to Families.
Plants Non- Flowering On Earth there are more than 250,000 different plants. Non-flowering plants do not have flowers or fruit not have seeds. They reproduce with spores, which are special cells that can grow into new plants. The spores have a strong cover to cover and protect. There are two main groups of nonflowering plants: MOSS: This species is small. They have a stalk of leaving a very small leaves. They have a root and not subject them to drink water. Water spread throughout the plant. Most live in very humid. When no water is dried and look like they are dead but when wet again be green. Moss thin out a column and its side is formed thicker capsule. Inside the spores are formed. FERNS: They are larger plants and mosses that live in very humid. They have an underground stem called a rhizome that is from where the roots and leaves. The leaves are very large. They are called fronds and are usually composed. The spores of ferns are behind leaves in a brown circles called sori. The second branch of plant classification corresponds to the upper floors. The structure of this group is clearly differentiated into root, stem and leaves. While mosses, licopodios and especially ferns present an important development in its structure can not be considered superior because it does not reproduce by seeds. This, which is the basis of reproduction, is found only in the upper floors to which it gives the name of espermatofitas. Their reproductive organs, flowers are visible although not showy. The seeds contain an embryo and nutrient reserves in a given moment emerge from the ground, able to germinate.
Higher plants include two groups are distinguished by the way they are seeds. These groups are gymnosperms and angiosperms. Gymnosperms Gymnosperms have naked seeds, and are seen in the fruit, between a hard and overlapping leaves called scales. An example of these fruits are pine cones. At present there are about 700 species of gymnosperms. Gymnosperms do not have flowers, but the seeds are formed from eggs placed in formations like more scarce as those that make up a pineapple. They are woody plants grow like bushes or trees and can reach gigantic sizes. The leaves are rudimentary, poorly developed ribs-and remain green throughout the year, as seen in the pines or firs. The leaves may be needle-shaped, as in the cedars, or flakes, as in the case of the cypress. Conducting vessels are less developed than those of angiosperms (group developed within the above) and produce a dense substance called resin. Typical representatives of gymnosperms are conifers, conical cup resinous trees that reach great heights. The most abundant are the pine, fir, larch, pine, birch and cypress. The flowers are inconspicuous, formed by scales which are then transformed into infructescenses-assemblyknown fruits as pineapples. The eggs, which give rise to seeds, are inserted in the axils of a protective woody scales. During the time of pollination pineapples guide its tip up and spread its scales to allow fertilization. Then close again to open them later. The female reproductive organs and male are different flowers. At the beginning of the formation of the plant, a taproot, ie sinks vertically as an extension of the trunk. After branching, and supports a cylindrical trunk. In general, the gymnosperms are grouped into forests, growing on calcareous or siliceous and resistant to frost, but weak against excessive moisture. The fact that forests grow clustered has great ecological importance. Economically, the main value lies in its coniferous wood and cellulose, a key element in the manufacture of paper. These trees are also grown as ornamentals. Conifers are distributed worldwide in temperate and cold regions and in mountain areas when the weather is warm. They cover much of the North American territory. There are numerous species of pines, cypresses, firs, junipers and cedars. In South America abound araucaria angustifolia as known as ParanĂĄ pine or Missionary, and the monkey puzzle tree Araucaria araucana or, in the NeuquĂŠn and Chile. The larch, however, abounds in Andean Patagonian forests. Angiosperms
Angiosperms are more evolved than gymnosperms. Its seeds are protected inside the fruit. The seeds of angiosperms are enclosed and protected within the fruit that is generated from the ovary. This branch of the upper floors is the largest in the plant kingdom, with about 25,000 species. They are herbaceous or woody and include herbs, bushes, shrubs and trees. There are epiphytes (plants that grow on other but without feeding on them) and parasites (which subsist by feeding on other plants). Most live on land, but there are also floating or submerged aquatic. Angiosperms grow worldwide, adapted to different environmental conditions.
Monocots and dicots Angiosperms are divided into monocots and dicots. The former are less evolved than the latter. Each group has different characteristics. In monocots, the seed is not divided, the embryo has one cotyledon called sheet. Flowers typically have three, six or nine petals, leaves have parallel ribs and roots are fasciculate, ie lacking a central axis. This subgroup comprises 40,000 angiosperm species growing mainly in temperate regions. Most are herbaceous, high economic value. These include grasses, such as wheat, corn, barley, rye, oats, millet or rice. The man advantage in their own food and as fodder, and uses the longest dry stalks into mats, ropes and roofs. Besides grasses, hyacinths, gladioli, lilies, lilies and orchids grow from seeds monocots, like palm trees and sugar cane. Finally there is the other group of angiosperms known as dicots. Its seeds have two cotyledons which are the first two leaves of the plant. The distinct features of monocots as well as the seed, the ribs are patterned network leaves, flowers of two or five petals, or multiples of those numbers, and taproot. The dicotyledonous species divided cover almost 200,000, according to the development of the flower, in sympetalous, dialipétalas and monoclamídeas. The sympetalous have flowers in the form of a tube or funnel. The petals are not entirely separate from each other, unlike the dialipétalas, whose flowers are clearly the disunited. Monoclamídeas have flowers without the corolla or calyx, unlike the previous two subgroups. Many times they are found together in individual inflorescences called catkins. Dicotyledonous plants are used by humans especially in the food industry, pharmacology, food and construction. They constitute more than half of the plant species that populate the planet and can be mentioned including roses, carnations, honeysuckle, violets, daisies, lotus, poppy, with flowers of endless shades also provide the perfume industry.
Dicotyledons are trees like willows, acacias, chestnuts, oaks, vegetables like beets, turnips, cabbage, watercress, carrots, parsley, potatoes, eggplant, tomatoes and lettuce, and watermelon, melon and thistle. Fruit trees are group known plum, apple, pear, cherry and olive. Reproduction in Higher Plants Under normal circumstances, all living things reproduce, ie, give rise to other individuals with similar characteristics. This makes possible the perpetuation of existing species. In higher plants are two different forms of reproduction: sexual and asexual or vegetative, which occurs in some species by dividing clumps, cuttings, etc.. Sexual reproduction The flower is equipped with a female organ, the ovary and one male, the stamens. Both involved in sexual reproduction gives rise to seeds. In the stamens are one or more stamens. Each consisting of a filament yarn, at whose end there is a lump called anther. In the anther is performed the production of pollen grains. It houses the pollen sacs, which produce pollen grains. These grains are very small particles, which in the most common flowers can be seen as a kind of yellow or colored powder. For fertilization to occur, pollen grains must reach the gynoecium. The latter structure is formed by modified leaves called carpels and consists of three parts: ovary, style and stigma. Ova in the ovary grow (at the origin of the seed). The style is a tubelike structure that connects the ovary with the stigma, where it settles the pollen grain at fertilization. The stigma secretes substances that hold the pollen grain and feed it so it can germinate. Grain follows then an extension, the pollen tube, which passes through the style and enters the ovary. For that migrates through generative nucleus which divides into two male gametes or sex cells. When one of these joins oosfera - the female gamete, directly into the egg-fertilization occurs and begin to differentiate the seed embryo. The other part of the generative nucleus fuses with the secondary nucleus has the egg to form a nutritive tissue that nourish the embryo. STAMENS DIFFERENT Blueberry Strawberry Tree Acacia Creek cyclamen Medinillo Pirola The flowers are not all equal in terms of their morphology: some are full or hermaphrodite gineceo may lack other (they are called male flowers), or of androceo (female flowers). They may also miss both: in this case the flowers are called neutral. This is one reason why some flowers are not self-fertilizing but perform outcrossing (between two flowers of the same species). This type of fertilization also responds to evolutionary mechanisms that favor the combination of genetic
material. That is why pollen can penetrate the stigma of the same flower or another flower of the same plant (selfing). However, it is very common cross-fertilization, in which the pollen grains penetrate the stigma of a flower located on another floor of the same species. Pollination For outcrossing occur, pollen must reach another plant. It focuses, wind, water, insects and birds. Based on these features three types of pollination: anemophilous, hydrophilic and zoophilic. In wind pollination, pollen grains are transported by wind and are scattered in the air. As you descend, alight on various surfaces, including flowers, some of which will be adequate. The wind-pollinated plants have flowers very simple and small, but the stigmas are usually large, feathery and abundant viscous juices, to which pollen grains adhere easily. They reproduce by wind-pollinated grasses (wheat, rye, corn), conifers (pine, fir) and nettles, among others. Hydrophilic pollination is taking place through the water. Only occurs in a few aquatic plants. In this case looks like filamentous pollen. Zoophilic pollination produced by higher animals. It involved ornithophilous if birds and insects entomophilous when engaged. To attract the animals, the flowers used various resources: bright colors, perfumes and producing delicious sweet juice called nectar. Insects and birds, seduced by these resources, land on flowers or penetrate them, and impregnated with pollen in different parts of the body. Later, fly to other plants, unintentionally deposited in them were transported grains. The perfumes emanating flowers attract insects from several feet away, the fumes are not always pleasant to humans. It is remarkable adaptive effort of many families of flowering plants in relation to insect pollinators. Thus, some flowers emanate her perfume during the day to attract diurnal insects, and others do it at night. TYPES OF STIGMA Rhubarb Snuff colchicum Saffron Silene Lino Yarrow Aconitum Certain plants support only be pollinated by a particular species and other insects retain come to sip their nectar, so that they stay in bloom until well impregnated with pollen.
Species In biology, a species (plural: species) is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, the difficulty of defining species is known as the species problem. Differing measures are often used, such as similarity of DNA, morphology or ecological niche. Presence of specific locally adapted traits may further subdivide species into "infraspecific taxa" such as subspecies (and in botany other taxa are used, such as varieties, subvarieties, and formae). Species hypothesized to have the same ancestors are placed in one genus, based on similarities. The similarity of species is judged based on comparison of physical attributes, especially their DNA sequences, where available. All species are given a two-part name, a "binomial name". The first part of a binomial name is the generic name, the genus of the species. The second part is either called the specific name (a term used only in zoology) or the specific epithet (the term used in botany, which can also be used in zoology). For example, Boa constrictor is one of four species of the Boa genus. The first part of the name is capitalized, and the second part has a lower case. The binomial name is written in italics when printed and underlined when handwritten.
A usable definition of the word "species" and reliable methods of identifying particular species are essential for stating and testing biological theories and for measuring biodiversity, though other taxonomic levels such as families may be considered in broad-scale studies. Extinct species known only from fossils are generally difficult to assign precise taxonomic rankings, which is why higher taxonomic levels such as families are often used for fossil-based studies. The total number of non-bacterial species in the world has been estimated at 8.7 million, with previous estimates ranging from two million to 100
A usable definition of the word "species" and reliable methods of identifying particular species is essential for stating and testing biological theories and for measuring biodiversity. Traditionally, multiple examples of a proposed species must be studied for unifying characters before it can be regarded as a species. It is generally difficult to give precise taxonomic rankings to extinct species known only from fossils. Some biologists may view species as statistical phenomena, as opposed to the traditional idea, with a species seen as a class of organisms. In that case, a species is defined as a separately
evolving lineage that forms a single gene pool. Although properties such as DNA-sequences and morphology are used to help separate closely related lineages, this definition has fuzzy boundaries. However, the exact definition of the term "species" is still controversial, particularly in prokaryotes, and this is called the species problem. Biologists have proposed a range of more precise definitions, but the definition used is a pragmatic choice that depends on the particularities of the species of concern
Published on Oct 22, 2013
Published on Oct 22, 2013
Plants, also called green plants (Viridiplantae in Latin), are living multicellular organisms of the kingdom Plantae. They form a clade that...