Physics and Chemistry
What is Chemistry
Chemistry is the study of matter, it's composition, structure and properties.
What is Physics
It is the study of force, mass, energy, and charge.
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This branch of sciences can help us as we want to explore the physical world. As we recall in the biological world Zoology, Botany, and Biology are some of the common branches of science that helps you in journeying the biological world. Here as we will enter the new world the 2 branches of science will help you along with your lesson.
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What is Physical Change?
Physical Change pertains to change that happens with in its physical state. For example, as we cut the papers the paper is still a paper the only change that occur is that the chancge of the shape. Just like with the water, if the watter freezes it is also an example of physical change.
There are many physical change that occurs in the nature can you name some?
What is Chemical Change?
Chemical Change is change that occurs not only with it's apearrance but also with it's composition. For example, as we burn a piece of paper, is it still a paper after we burned it? It will become ashes therefore the paper is not anymore a paper because it turned into ashes and as we go on our deeper understanding ashes is different with paper. It is an another object. Another example is the burning of a match stick.
There are also many chemical change that occurs in the nature can you name some?
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-changes on me-
Saturday, October 18, 2008
Friday, October 17, 2008
All About Matter
ALL ABOUT MATTER
What is a matter?
What is a matter?
Common definition
The common definition of matter is anything which both occupies space and has mass. For example, a car would be said to be made of matter, as it occupies space, and has mass. In chemistry, this is often taken to mean what atoms and molecules are made of, meaning anything made of protons, neutrons, and electrons. For example, phosphorus sesquisulfide is a molecule made of four atoms of phosphorus, and three of sulfur (see image on right), and is thus considered to be matter.
What are the Phases of Matter
The 4 phases of matter are Solid, Liquid, Gas and Plasma.
Solid
Main article: Solid
Solids are characterized by a tendency to retain their structural integrity; if left on their own, they will not spread in the same way gas or liquids would. Many solids, like rocks and concrete, have very high hardness and rigidity and will tend to break or shatter when subject to various forms of stress, but others like steel and paper are more flexible and will bend. Solids are often composed of crystals, glasses, or long chain molecules (e.g. rubber and paper).
Liquid
Main article: Liquid
In a liquid, the molecules are frequently touching, but able to move around each other. So unlike a gas, it has cohesion and viscosity. While unlike a solid, it is not highly rigid.
Gas
Main article: Gas
A gas is a substance composed of small molecules which are spaced far enough apart from each other that they rarely interact and do not impeded each others' motion. Thus a gas has no resistance to changing shape (beyond the inertia of the molecules which have to be knocked aside).
Plasma
Main article: Plasma
A plasma is a gas which is so hot that many of the molecules are electrically charged. Thus it interacts with electric and magnetic fields.
Gas and Plasma are they the same?
Yes, in nature but No, in the characteristics.
How do Gas and Plasma differ?
They differ because plasma is packed with energy that they can interact with other molecules.
Thursday, October 2, 2008
Mosses , Plant or not?
Mosses (Bryophyta) are quite interesting, simple green land plants with leaves and a stem and always without roots. In many mosses, the leaves are only one cell thick, except for the midribs, which are sometimes present. So the leaves are easy objects for the microscope. The plant is normally attached to the ground by delicate, colourless or brown threads, the rhizoids.
There are two major groups in the Bryophyta: Mosses (Musci) and Liverworts (Hepaticae).
Most mosses are found in areas with a humid and a cold to moderate warm climate. In the tropics, mosses are found especially in the mountains. In Europe, the south western part of Ireland is a paradise for mosses.
Mosses can reproduce asexually, by means of small clusters of cells or plates of tissue which break away and germinate to become new plants. Especially liverworts do this.
The normal, sexual method of reproduction however, involves special organs, the antheridia and the archegonia. These organs are the interesting parts for the microscopist who is interested in the biology of mosses. In the Musci the antheridium is the male organ, a delicate sac in which the male gametes are formed. It has a greyish or brown colour and an ovoid or globose form. It is a spectacular sight to see the male gametes, with two flagella, escape under the microscope from the antheridium. These antheridia are normally accompanied by numerous short filaments of cells, the paraphyses (see right image).
The archegonium is easy to recognize, with a shape like a little bottle or flask. So look carefully with a hand lens among wet patches of mosses, archegonia and antheridia are often found in special cups of leaves.
paraphysis with archegonium
I always try to study first some of the common microscopical objects in detail, especially their biology and then try to determine the names of the species that are more difficult to find. So I studied very common mosses to see some details of their reproduction.
The male gametes, escaping from the antheridia, need water to reach the egg in the archegonium. After fertilization, the egg develops in most cases into a spore-containing capsule on a stalk called a seta. Capsule and seta together form the so called sporophyte. At maturity, the capsule sheds the spores as a fine dust. The spores can be held back in wet weather by a mechanism whereby the teeth of the capsule close it.
Mosses can have one or two rows of teeth, (images left and below), an important aspect for the determination.
In the leafy liverworts, the antheridia generally occur in a packet-like swelling, the androecium, which develops on the lower portion of a modified leaf. The sporophyte develops from the archegonium. The seta is very delicate, often white and glassy, grows very fast and perishes after the shedding of the spores. The capsule is black, often globose or ellipsoid.
In most species the capsule (sporangium) peels open in four sections (image above), exposing the spores and the elaters, cells which have helically arranged moisture absorbing wall thickenings. (
These cells are sensitive to slight changes in humidity, causing a twisting action that aids in dispersing the spores. The elaters are initially attached at both ends to the sporangium. Upon drying, one end of each elater snaps loose from the center of the sporangium, spreading the spores.
Marchantia polymorpha, a more complicated liverwort, is common in flowerpots in green houses, on moist bricks in gardens and on badly drained soils. On its leaves we can see small cups, (gemma cups) with small oval pieces of tissue, which can be spread by rain drops and become new plants
gemma cups
This dioecious liverwort is known immediately by the male and female "umbrellas".
These umbrellas carry the male and female receptacles. The numerous sporogonia develop on the underside of the umbrellas; each capsule contains spores and elaters.
the male umbrella
the female umbrellas
You may call mosses simple plants, but important biological processes are easily studied by looking carefully at these sometimes fascinating plants.
There are two major groups in the Bryophyta: Mosses (Musci) and Liverworts (Hepaticae).
Most mosses are found in areas with a humid and a cold to moderate warm climate. In the tropics, mosses are found especially in the mountains. In Europe, the south western part of Ireland is a paradise for mosses.
Mosses can reproduce asexually, by means of small clusters of cells or plates of tissue which break away and germinate to become new plants. Especially liverworts do this.
The normal, sexual method of reproduction however, involves special organs, the antheridia and the archegonia. These organs are the interesting parts for the microscopist who is interested in the biology of mosses. In the Musci the antheridium is the male organ, a delicate sac in which the male gametes are formed. It has a greyish or brown colour and an ovoid or globose form. It is a spectacular sight to see the male gametes, with two flagella, escape under the microscope from the antheridium. These antheridia are normally accompanied by numerous short filaments of cells, the paraphyses (see right image).
The archegonium is easy to recognize, with a shape like a little bottle or flask. So look carefully with a hand lens among wet patches of mosses, archegonia and antheridia are often found in special cups of leaves.
paraphysis with archegonium
I always try to study first some of the common microscopical objects in detail, especially their biology and then try to determine the names of the species that are more difficult to find. So I studied very common mosses to see some details of their reproduction.
The male gametes, escaping from the antheridia, need water to reach the egg in the archegonium. After fertilization, the egg develops in most cases into a spore-containing capsule on a stalk called a seta. Capsule and seta together form the so called sporophyte. At maturity, the capsule sheds the spores as a fine dust. The spores can be held back in wet weather by a mechanism whereby the teeth of the capsule close it.
Mosses can have one or two rows of teeth, (images left and below), an important aspect for the determination.
In the leafy liverworts, the antheridia generally occur in a packet-like swelling, the androecium, which develops on the lower portion of a modified leaf. The sporophyte develops from the archegonium. The seta is very delicate, often white and glassy, grows very fast and perishes after the shedding of the spores. The capsule is black, often globose or ellipsoid.
In most species the capsule (sporangium) peels open in four sections (image above), exposing the spores and the elaters, cells which have helically arranged moisture absorbing wall thickenings. (
These cells are sensitive to slight changes in humidity, causing a twisting action that aids in dispersing the spores. The elaters are initially attached at both ends to the sporangium. Upon drying, one end of each elater snaps loose from the center of the sporangium, spreading the spores.
Marchantia polymorpha, a more complicated liverwort, is common in flowerpots in green houses, on moist bricks in gardens and on badly drained soils. On its leaves we can see small cups, (gemma cups) with small oval pieces of tissue, which can be spread by rain drops and become new plants
gemma cups
This dioecious liverwort is known immediately by the male and female "umbrellas".
These umbrellas carry the male and female receptacles. The numerous sporogonia develop on the underside of the umbrellas; each capsule contains spores and elaters.
the male umbrella
the female umbrellas
You may call mosses simple plants, but important biological processes are easily studied by looking carefully at these sometimes fascinating plants.
Photosynthesis by wikipedia.com
Photosynthesis uses light energy and carbon dioxide to make triose phosphates (G3P). G3P is generally considered the first end-product of photosynthesis.[citation needed] It can be used as a source of metabolic energy, or combined and rearranged to form monosaccharide or disaccharide sugars, such as glucose or sucrose, respectively, which can be transported to other cells, stored as insoluble polysaccharides such as starch, or converted to structural carbohydrates, such as cellulose or glucans.
A commonly used slightly simplified equation for photosynthesis is:
6 CO2(g) + 12 H2O(l) + photons → C6H12O6(aq) + 6 O2(g) + 6 H2O(l)
carbon dioxide + water + light energy → glucose + oxygen + water
The equation is often presented in introductory chemistry texts in an even more simplified form as:[2]
6 CO2(g) + 6 H2O(l) + photons → C6H12O6(aq) + 6 O2(g)
Photosynthesis occurs in two stages. In the first stage, light-dependent reactions or photosynthetic reactions (also called the Light Reactions) capture the energy of light and use it to make high-energy molecules. During the second stage, the light-independent reactions (also called the Calvin-Benson Cycle, and formerly known as the Dark Reactions) use the high-energy molecules to capture and chemically reduce carbon dioxide (CO2) (also called carbon fixation) to make the precursors of carbohydrates.
In the light reactions, one molecule of the pigment chlorophyll absorbs one photon and loses one electron. This electron is passed to a modified form of chlorophyll called pheophytin, which passes the electron to a quinone molecule, allowing the start of a flow of electrons down an electron transport chain that leads to the ultimate reduction of NADP to NADPH. In addition, this creates a proton gradient across the chloroplast membrane; its dissipation is used by ATP Synthase for the concomitant synthesis of ATP. The chlorophyll molecule regains the lost electron from a water molecule through a process called photolysis, which releases a dioxygen (O2) molecule.
In the Light-independent or dark reactions the enzyme RuBisCO captures CO2 from the atmosphere and in a process that requires the newly formed NADPH, called the Calvin-Benson Cycle, releases three-carbon sugars, which are later combined to form sucrose and starch.
Photosynthesis may simply be defined as the conversion of light energy into chemical energy by living organisms. It is affected by its surroundings, and the rate of photosynthesis is affected by the concentration of carbon dioxide in the air, the light intensity, and the temperature.
Photosynthesis uses only 1% of the entire electromagnetic spectrum, and 2% of the visible spectrum.[citation needed] It has been estimated that the productivity of photosythesis is 115 petagrams (Pg, equals 1015 grams or 109 metric tons).[citation needed]
In plants
Most plants are photoautotrophs, which means that they are able to synthesize food directly from inorganic compounds using light energy - for example from the sun, instead of eating other organisms or relying on nutrients derived from them. This is distinct from chemoautotrophs that do not depend on light energy, but use energy from inorganic compounds.
6 CO2 + 12 H2O → C6H12O6 + 6 O2 + 6 H2O
The energy for photosynthesis ultimately comes from absorbed photons and involves a reducing agent, which is water in the case of plants, releasing oxygen as product. The light energy is converted to chemical energy (known as light-dependent reactions), in the form of ATP and NADPH, which are used for synthetic reactions in photoautotrophs. The overall equation for the light-dependent reactions under the conditions of non-cyclic electron flow in green plants is:[3]
2 H2O + 2 NADP+ + 2 ADP + 2 Pi + light → 2 NADPH + 2 H+ + 2 ATP + O2
Most notably, plants use the chemical energy to fix carbon dioxide into carbohydrates and other organic compounds through light-independent reactions. The overall equation for carbon fixation (sometimes referred to as carbon reduction) in green plants is:[3]
3 CO2 + 9 ATP + 6 NADPH + 6 H+ → C3H6O3-phosphate + 9 ADP + 8 Pi + 6 NADP+ + 3 H2O
To be more specific, carbon fixation produces an intermediate product, which is then converted to the final carbohydrate products. The carbon skeletons produced by photosynthesis are then variously used to form other organic compounds, such as the building material cellulose, as precursors for lipid and amino acid biosynthesis, or as a fuel in cellular respiration. The latter occurs not only in plants but also in animals when the energy from plants gets passed through a food chain. Organisms dependent on photosynthetic and chemosynthetic organisms are called heterotrophs. In general outline, cellular respiration is the opposite of photosynthesis: Glucose and other compounds are oxidized to produce carbon dioxide, water, and chemical energy. However, the two processes take place through a different sequence of chemical reactions and in different cellular compartments.
Plants absorb light primarily using the pigment chlorophyll, which is the reason that most plants have a green color. The function of chlorophyll is often supported by other accessory pigments such as carotenes and xanthophylls. Both chlorophyll and accessory pigments are contained in organelles (compartments within the cell) called chloroplasts. Although all cells in the green parts of a plant have chloroplasts, most of the energy is captured in the leaves. The cells in the interior tissues of a leaf, called the mesophyll, can contain between 450,000 and 800,000 chloroplasts for every square millimeter of leaf. The surface of the leaf is uniformly coated with a water-resistant waxy cuticle that protects the leaf from excessive evaporation of water and decreases the absorption of ultraviolet or blue light to reduce heating. The transparent epidermis layer allows light to pass through to the palisade mesophyll cells where most of the photosynthesis takes place.
Plants convert light into chemical energy with a maximum photosynthetic efficiency of approximately 6%.[4][5][6] By comparison solar panels convert light into electric energy at a photosynthetic efficiency of approximately 10-20%. Actual plant's photosynthetic efficiency varies with the frequency of the light being converted, light intensity, temperature and proportion of CO2 in atmosphere.
A commonly used slightly simplified equation for photosynthesis is:
6 CO2(g) + 12 H2O(l) + photons → C6H12O6(aq) + 6 O2(g) + 6 H2O(l)
carbon dioxide + water + light energy → glucose + oxygen + water
The equation is often presented in introductory chemistry texts in an even more simplified form as:[2]
6 CO2(g) + 6 H2O(l) + photons → C6H12O6(aq) + 6 O2(g)
Photosynthesis occurs in two stages. In the first stage, light-dependent reactions or photosynthetic reactions (also called the Light Reactions) capture the energy of light and use it to make high-energy molecules. During the second stage, the light-independent reactions (also called the Calvin-Benson Cycle, and formerly known as the Dark Reactions) use the high-energy molecules to capture and chemically reduce carbon dioxide (CO2) (also called carbon fixation) to make the precursors of carbohydrates.
In the light reactions, one molecule of the pigment chlorophyll absorbs one photon and loses one electron. This electron is passed to a modified form of chlorophyll called pheophytin, which passes the electron to a quinone molecule, allowing the start of a flow of electrons down an electron transport chain that leads to the ultimate reduction of NADP to NADPH. In addition, this creates a proton gradient across the chloroplast membrane; its dissipation is used by ATP Synthase for the concomitant synthesis of ATP. The chlorophyll molecule regains the lost electron from a water molecule through a process called photolysis, which releases a dioxygen (O2) molecule.
In the Light-independent or dark reactions the enzyme RuBisCO captures CO2 from the atmosphere and in a process that requires the newly formed NADPH, called the Calvin-Benson Cycle, releases three-carbon sugars, which are later combined to form sucrose and starch.
Photosynthesis may simply be defined as the conversion of light energy into chemical energy by living organisms. It is affected by its surroundings, and the rate of photosynthesis is affected by the concentration of carbon dioxide in the air, the light intensity, and the temperature.
Photosynthesis uses only 1% of the entire electromagnetic spectrum, and 2% of the visible spectrum.[citation needed] It has been estimated that the productivity of photosythesis is 115 petagrams (Pg, equals 1015 grams or 109 metric tons).[citation needed]
In plants
Most plants are photoautotrophs, which means that they are able to synthesize food directly from inorganic compounds using light energy - for example from the sun, instead of eating other organisms or relying on nutrients derived from them. This is distinct from chemoautotrophs that do not depend on light energy, but use energy from inorganic compounds.
6 CO2 + 12 H2O → C6H12O6 + 6 O2 + 6 H2O
The energy for photosynthesis ultimately comes from absorbed photons and involves a reducing agent, which is water in the case of plants, releasing oxygen as product. The light energy is converted to chemical energy (known as light-dependent reactions), in the form of ATP and NADPH, which are used for synthetic reactions in photoautotrophs. The overall equation for the light-dependent reactions under the conditions of non-cyclic electron flow in green plants is:[3]
2 H2O + 2 NADP+ + 2 ADP + 2 Pi + light → 2 NADPH + 2 H+ + 2 ATP + O2
Most notably, plants use the chemical energy to fix carbon dioxide into carbohydrates and other organic compounds through light-independent reactions. The overall equation for carbon fixation (sometimes referred to as carbon reduction) in green plants is:[3]
3 CO2 + 9 ATP + 6 NADPH + 6 H+ → C3H6O3-phosphate + 9 ADP + 8 Pi + 6 NADP+ + 3 H2O
To be more specific, carbon fixation produces an intermediate product, which is then converted to the final carbohydrate products. The carbon skeletons produced by photosynthesis are then variously used to form other organic compounds, such as the building material cellulose, as precursors for lipid and amino acid biosynthesis, or as a fuel in cellular respiration. The latter occurs not only in plants but also in animals when the energy from plants gets passed through a food chain. Organisms dependent on photosynthetic and chemosynthetic organisms are called heterotrophs. In general outline, cellular respiration is the opposite of photosynthesis: Glucose and other compounds are oxidized to produce carbon dioxide, water, and chemical energy. However, the two processes take place through a different sequence of chemical reactions and in different cellular compartments.
Plants absorb light primarily using the pigment chlorophyll, which is the reason that most plants have a green color. The function of chlorophyll is often supported by other accessory pigments such as carotenes and xanthophylls. Both chlorophyll and accessory pigments are contained in organelles (compartments within the cell) called chloroplasts. Although all cells in the green parts of a plant have chloroplasts, most of the energy is captured in the leaves. The cells in the interior tissues of a leaf, called the mesophyll, can contain between 450,000 and 800,000 chloroplasts for every square millimeter of leaf. The surface of the leaf is uniformly coated with a water-resistant waxy cuticle that protects the leaf from excessive evaporation of water and decreases the absorption of ultraviolet or blue light to reduce heating. The transparent epidermis layer allows light to pass through to the palisade mesophyll cells where most of the photosynthesis takes place.
Plants convert light into chemical energy with a maximum photosynthetic efficiency of approximately 6%.[4][5][6] By comparison solar panels convert light into electric energy at a photosynthetic efficiency of approximately 10-20%. Actual plant's photosynthetic efficiency varies with the frequency of the light being converted, light intensity, temperature and proportion of CO2 in atmosphere.
Food chain
Food chains, also called, food networks and/or trophic networks, describe the feeding relationships between species within an ecosystem. Organisms are connected to the organisms they consume by arrows representing the direction of biomass or energy transfer. It also shows how the energy from the producer is given to the consumer.Typically a food chain or food web refers to a graph where only connections are recorded, and a food network or ecosystem network refers to a network where the connections are given weights representing the quantity of nutrients or energy being transferred.
A food chain is the flow of energy from one organism to the next and to the next and to the next. Organisms in a food chain are grouped into trophic levels,based on how many links they are removed from the primary producers. Trophic levels may contain either a single species or a group of species that are presumed to share both predators and prey. They usually start with a plant and end with a carnivore. The diagram at right is a food chain from a Swedish lake. It can be described as follows: osprey feed on northern pike that feed on perch that eat bleak that feed on freshwater shrimp. Although they are not shown in this diagram, the primary producers of this food chain are probably autotrophic phytoplankton. Phytoplankton and algae form the base of most freshwater food chains. It is often the case that biomass of each trophic level decreases from the base of the chain to the top. This is because energy is lost to the environment with each transfer. On average, only 10% of the organism's energy is passed on to its predator. The other 90% is used for the organism's life processes or it is lost as heat to the environment. Graphic representations of the biomass or productivity at each tropic level are called trophic pyramids. In this food chain for example, the biomass of osprey is smaller than the biomass of pike, which is smaller than the biomass of perch. Some producers, especially phytoplankton, are so productive and have such a high turnover rate that they can actually support a larger biomass of grazers. This is called an inverted pyramid, and can occur when consumers live longer and grow more slowly than the organisms they consume. In this food chain, the productivity of phytoplankton is much greater than that of the zooplankton consuming them. The biomass of the phytoplankton, however, may actually be less than that of the copepods. Directly linked to this are pyramids of numbers, which show that as the chain is travelled along, the number of consumers at each level drops very significantly, so that a single top consumer (e.g. a Polar Bear) will be supported by literally millions of separate producers (e.g. Phytoplankton). i am doing some school research. any help at any time wud be appreciated greatly! tanx for the support
A food chain is the flow of energy from one organism to the next and to the next and to the next. Organisms in a food chain are grouped into trophic levels,based on how many links they are removed from the primary producers. Trophic levels may contain either a single species or a group of species that are presumed to share both predators and prey. They usually start with a plant and end with a carnivore. The diagram at right is a food chain from a Swedish lake. It can be described as follows: osprey feed on northern pike that feed on perch that eat bleak that feed on freshwater shrimp. Although they are not shown in this diagram, the primary producers of this food chain are probably autotrophic phytoplankton. Phytoplankton and algae form the base of most freshwater food chains. It is often the case that biomass of each trophic level decreases from the base of the chain to the top. This is because energy is lost to the environment with each transfer. On average, only 10% of the organism's energy is passed on to its predator. The other 90% is used for the organism's life processes or it is lost as heat to the environment. Graphic representations of the biomass or productivity at each tropic level are called trophic pyramids. In this food chain for example, the biomass of osprey is smaller than the biomass of pike, which is smaller than the biomass of perch. Some producers, especially phytoplankton, are so productive and have such a high turnover rate that they can actually support a larger biomass of grazers. This is called an inverted pyramid, and can occur when consumers live longer and grow more slowly than the organisms they consume. In this food chain, the productivity of phytoplankton is much greater than that of the zooplankton consuming them. The biomass of the phytoplankton, however, may actually be less than that of the copepods. Directly linked to this are pyramids of numbers, which show that as the chain is travelled along, the number of consumers at each level drops very significantly, so that a single top consumer (e.g. a Polar Bear) will be supported by literally millions of separate producers (e.g. Phytoplankton). i am doing some school research. any help at any time wud be appreciated greatly! tanx for the support
Plant Kingdom
Plant Kingdom
Bryophytes: Small with leaflike, stemlike, and rootlike structures.
which are Disseminated by spores: mosses, liverworts, hornworts.
Tracheophytes: Larger with true leaves, stems, and roots.
Seedless: Ferns, horsetails, club mosses.
Seed Plants:
Gymnosperms: Usually have cones, no flowers, seeds not enclosed in fruit: pines, spruces, firs, hemlocks, cycads, ginkgo.
Angiosperms: Have flowers, seeds enclosed in fruit
Monocotyledons: Leaves have parallel veins, one seed leaf: grasses, orchids, lilies, palms.
Dicotyledons: Leaves have netted veins, two seed leaves: cherry trees, maples, coffee, daisies, etc.
This informal way of describing plant classification gives an overview of how plants are classified. Botanists use a more complex system. A botanist divides the plant kingdom into Divisions, similar to the Phyla used to divide the animal kingdom. There are twelve divisions. Referring to the above ranking, three of these divisions are Bryophytes, four are seedless plants, four are Gymnosperms, and one is Angiosperms. Each Division is further divided into Classes, which are divided into Orders, which are divided into Families, which are divided into Genera (singular, Genus), which are divided into species, which is the "basic unit" of classification. Put somewhat simply, individuals in a species are able to breed with each other, while in broader categories individuals do not interbreed.
THE BINOMIAL SYSTEM OF CLASSIFICATION
The foxglove plant is the source of digitalis.Photo by Steven R. King, 1996.The scientific or botanical name of a plant is the means by which we give it its unique place in the scientific and biological world. Begun by Carolus Linneaus, a Swedish botanist, in the eighteenth century, this name is binomial (has two parts), consisting of genus and species, both of which are expressed in Latin. The genus or generic name is a noun which usually names some aspect of a plant, such as Coffea, the Latinized form of the Arabic word for beverage, kahwah. The species or specific name is usually an adjective that describes the genus. In the case of coffee, the species is arabica, indicating that the plant was thought to originate in Arabia. The coffee plant botanical name, Coffea arabica, refers to only one plant and cannot be confused with any other. Its botanical name is unique to that particular plant the world over.
The botanical name is often followed by a letter or letters which stand for the botanist who named that plant. The coffee plant's complete botanical name is Coffea arabica L., the L. standing for Linneaus. If the original botanical name of a plant is later changed, the original classifier is still noted in parentheses. Other often used abbreviations are Sarg. for Charles Sprague Sargent, founder of Harvard University's Arnold Arboretum; Lam. for Jean Baptiste Lamarck, French evolutionist and botanist; and Audub. for John James Audubon, ornithologist, naturalist, and painter. (Interestingly, this convention of naming the discoverer is not found in the naming of animals.) Sometimes the Family name is included, which groups the genera. It can usually be distinguished by its ending--"eae."
Linneaus's book Species Plantarum (The Species of Plants), published in 1753, continues to influence the naming of plants today. It is the starting point for checking whether a name has been used previously to insure that each plant is given a unique name. The earliest name for a plant is usually the official name should a dispute arise.
Bryophytes: Small with leaflike, stemlike, and rootlike structures.
which are Disseminated by spores: mosses, liverworts, hornworts.
Tracheophytes: Larger with true leaves, stems, and roots.
Seedless: Ferns, horsetails, club mosses.
Seed Plants:
Gymnosperms: Usually have cones, no flowers, seeds not enclosed in fruit: pines, spruces, firs, hemlocks, cycads, ginkgo.
Angiosperms: Have flowers, seeds enclosed in fruit
Monocotyledons: Leaves have parallel veins, one seed leaf: grasses, orchids, lilies, palms.
Dicotyledons: Leaves have netted veins, two seed leaves: cherry trees, maples, coffee, daisies, etc.
This informal way of describing plant classification gives an overview of how plants are classified. Botanists use a more complex system. A botanist divides the plant kingdom into Divisions, similar to the Phyla used to divide the animal kingdom. There are twelve divisions. Referring to the above ranking, three of these divisions are Bryophytes, four are seedless plants, four are Gymnosperms, and one is Angiosperms. Each Division is further divided into Classes, which are divided into Orders, which are divided into Families, which are divided into Genera (singular, Genus), which are divided into species, which is the "basic unit" of classification. Put somewhat simply, individuals in a species are able to breed with each other, while in broader categories individuals do not interbreed.
THE BINOMIAL SYSTEM OF CLASSIFICATION
The foxglove plant is the source of digitalis.Photo by Steven R. King, 1996.The scientific or botanical name of a plant is the means by which we give it its unique place in the scientific and biological world. Begun by Carolus Linneaus, a Swedish botanist, in the eighteenth century, this name is binomial (has two parts), consisting of genus and species, both of which are expressed in Latin. The genus or generic name is a noun which usually names some aspect of a plant, such as Coffea, the Latinized form of the Arabic word for beverage, kahwah. The species or specific name is usually an adjective that describes the genus. In the case of coffee, the species is arabica, indicating that the plant was thought to originate in Arabia. The coffee plant botanical name, Coffea arabica, refers to only one plant and cannot be confused with any other. Its botanical name is unique to that particular plant the world over.
The botanical name is often followed by a letter or letters which stand for the botanist who named that plant. The coffee plant's complete botanical name is Coffea arabica L., the L. standing for Linneaus. If the original botanical name of a plant is later changed, the original classifier is still noted in parentheses. Other often used abbreviations are Sarg. for Charles Sprague Sargent, founder of Harvard University's Arnold Arboretum; Lam. for Jean Baptiste Lamarck, French evolutionist and botanist; and Audub. for John James Audubon, ornithologist, naturalist, and painter. (Interestingly, this convention of naming the discoverer is not found in the naming of animals.) Sometimes the Family name is included, which groups the genera. It can usually be distinguished by its ending--"eae."
Linneaus's book Species Plantarum (The Species of Plants), published in 1753, continues to influence the naming of plants today. It is the starting point for checking whether a name has been used previously to insure that each plant is given a unique name. The earliest name for a plant is usually the official name should a dispute arise.
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