Showing posts with label Biology. Show all posts
Showing posts with label Biology. Show all posts
Deforestation
The term deforestation connotes transformation of forested land to permanently cleared land or to a shifting-cultivation cycle1. It involves permanent destruction of forest land by virtue of human activities such as logging and burning of trees in forested regions.
Global warming
Deforestation and destruction of rainforests have several adverse consequences, the most significant being global warming, which occurs due to increased atmospheric concentrations of greenhouse gases, in turn, raising the global mean temperature. Carbon-dioxide or CO2 is the main greenhouse gas. Trees absorb CO2 reducing its concentration in the environment. Conversely, forest clearance and wood burning add to the concentration of CO2 in the atmosphere. Destruction of forests implies lesser trees to absorb the greenhouse gas promoting global warming. Research indicates that deforestation, biomass burning and other land use practices account for over 18 percent of enhanced radiative forces causing global warming, far outweighing the effects of carbon emissions from planes, automobiles and factories With the extent of deforestation worldwide, its impact on global warming knows no bounds. For example, 500 million tonnes of CO2 were released into the atmosphere as a consequence of the 1987 burning of the Amazon rain forest. In another instance, the forest fires of Indonesia in 1997 consumed over a million hectares of forest land created a cloud of smog over all of Southeast Asia, from Thailand to Philippines, for over a month, in addition to their effect on global climate.
Global warming
Deforestation and destruction of rainforests have several adverse consequences, the most significant being global warming, which occurs due to increased atmospheric concentrations of greenhouse gases, in turn, raising the global mean temperature. Carbon-dioxide or CO2 is the main greenhouse gas. Trees absorb CO2 reducing its concentration in the environment. Conversely, forest clearance and wood burning add to the concentration of CO2 in the atmosphere. Destruction of forests implies lesser trees to absorb the greenhouse gas promoting global warming. Research indicates that deforestation, biomass burning and other land use practices account for over 18 percent of enhanced radiative forces causing global warming, far outweighing the effects of carbon emissions from planes, automobiles and factories With the extent of deforestation worldwide, its impact on global warming knows no bounds. For example, 500 million tonnes of CO2 were released into the atmosphere as a consequence of the 1987 burning of the Amazon rain forest. In another instance, the forest fires of Indonesia in 1997 consumed over a million hectares of forest land created a cloud of smog over all of Southeast Asia, from Thailand to Philippines, for over a month, in addition to their effect on global climate.
Bacteria
Classification of Bacteria
Bacteria and blue-green algae are prokaryotes—that is, they are organisms that lack membranes surrounding their genetic material. Today most scientists place prokaryotes in the kingdom Monera. Formerly, bacteria and blue-green algae were considered to be primitive plants and were classified in the plant kingdom.
Bacteria are generally classified by two methods. The simplest and oldest method is by shape. The three principal categories are:
Bacilli
(singular: Bacillus), rod-shaped bacteria; the most numerous of all types. They include coccobacilli and streptobacilli.
Cocci
(singular: Coccus), spherical bacteria. This group is divided into bacteria that occur in pairs, such as the diplococci; in clusters, such as the staphylococci; and in chains, such as the streptococci.
Bacteria and blue-green algae are prokaryotes—that is, they are organisms that lack membranes surrounding their genetic material. Today most scientists place prokaryotes in the kingdom Monera. Formerly, bacteria and blue-green algae were considered to be primitive plants and were classified in the plant kingdom.
Bacteria are generally classified by two methods. The simplest and oldest method is by shape. The three principal categories are:
Bacilli
(singular: Bacillus), rod-shaped bacteria; the most numerous of all types. They include coccobacilli and streptobacilli.
Cocci
(singular: Coccus), spherical bacteria. This group is divided into bacteria that occur in pairs, such as the diplococci; in clusters, such as the staphylococci; and in chains, such as the streptococci.
Planting Mustard Seeds: How To Grow Mustard Seed Plants
Many people do not realize that a mustard seed plant is the same plant as a mustard greens plant (Brassica juncea). This versatile plant can be grown as a vegetable and eaten like other greens or, if allowed to flower and go to seed, mustard seeds can be harvested and used as a spice in cooking or ground into a popular condiment. Learning how to grow mustard seeds is easy and rewarding.mustard seeds is easy and rewarding.
3 Types of Animal Tissues
Some of the major types of animal tissues are as follows: (i) Epithelial Tissue (ii) Connective Tissue (iii) Muscle Tissue.
In multicellular animals, a group of similar cells along with intercellular stances perform a specific function. Such an organization is known as tissue.
All complex animals consist of only four basic types of tissues. These tissues organized in specific proportion and pattern to form an organ like stomach, lung, heart and kidney.
The tissues are of types namely:
(i) Epithelial,
(ii) Connective,
(iii) Muscular,
Differentiate between simple and compound tissues?
Simple tissues
- Made up of the same type of cells.
- Covers the surface of internal (e.g. brain) and external (e.g. skin) organs.
- The cells are packed tightly together.
- Called epithelium in animals and epidermis in plants.
- Examples are the muscle tissue in animals and dermal tissue in plants.
- Made up of the same type of cells.
- Covers the surface of internal (e.g. brain) and external (e.g. skin) organs.
- The cells are packed tightly together.
- Called epithelium in animals and epidermis in plants.
- Examples are the muscle tissue in animals and dermal tissue in plants.
Structure and Functions of Muscular Tissue
There are 3 types of muscle tissue:
- Skeletal muscle tissue,
- Cardiac muscle tissue, and
- Smooth muscle tissue.
The structure of these muscle tissues can be described from the level of detail of the muscle fibres (muscle cells) through all the other muscle structures and parts of structures that bind muscle cells together enabling them to perform their functions.
The functions of muscle tissues depend on the type of muscle tissues and their locations in the body.
Here is an overview of the 3 types of muscle tissues:
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(a) Skeletal Muscle Tissue
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Supporting Tissue
It is a type of connective tissue in which the matrix is hard and rigid due to the presence of inorganic salts. The matrix encloses few cells. Fibres may be present or absent. It is also known as skeletal tissue since it forms the internal supporting framework (endoskeleton) of the body.
Types of supporting tissue
Based on the components of matrix, supporting tissue can be classified into
1. Cartilage
2. BoneCartilage
t is a type of supporting tissue in which the matrix is characterized by more of organic substances (nearly 85%). The rigid, homogenous matrix is known as chondrin. It lies enclosed in a fibrous connective tissue covering called perichondrium. Chondrin encloses numerous spherical or oval spaces called lacunae. Each lacuna contains either 1 or 2 or 4 cartilage cells or chondriocytes. These cells are capable of limited mitotic divisions. Fibres may be present or absent.
Osmosis: Definition, Examples
Water moves across cell membranes by osmosis to try to equalize the concentration of solutes on both sides of the membrane. In this lesson, learn how osmosis works and examine some examples of its importance in biology.
We also recommend watching Osmosis, Diffusion and Saturation and Passive Transport in Cells: Simple and Facilitated Diffusion & Osmosis
Definition
Did anyone ever tell you that you should sleep with your chemistry book under your pillow to 'learn by osmosis'? Sounds like an easy way to study for an exam, but as anyone who's ever tried it knows, it doesn't actually work.
But osmosis is real! Osmosis is the flow of water down its concentration gradient, across a semi-permeable membrane. Osmosis is an example of diffusion, which is when molecules tend to distribute themselves evenly in a space.
What's a semi-permeable membrane? It's a membrane or barrier that allows some molecules or substances to cross, but not others. An everyday example is the plastic wrap in your kitchen: it allows air and water vapor to travel across it, but not water or food. The membranes of cells are semi-permeable, too. They allow water and certain solutes (small molecules that are dissolved in asolvent such as water) to cross, but other solutes cannot cross.
Xylem
Xylem is a complex tissue composed of xylem vessels, xylem tracheids, xylem fibres and xylem parenchyma.
- Xylem vessels: Xylem vessels comprise a vertical chain of lengthened, dead cells known as vessel elements. The cells are arranged end to endand the cross-walls dissolve completely or have simple or complex perforation plates between successive cells. The secondary walls of vessels are impregnated with lignin and are thickened unevenly. The walls of the vessels may be thickened in different ways, e.g. annular, spiral and pitted thickening may be observed.
- Xylem tracheids: A tracheids is an elongated cell, the contents of which are non-living. The cell walls are thickened, impregnated with ligninand the lumen is smaller. As in the case of vessels, there is a differentiation between annular, spiral and pitted tracheids again caused by the type of thickening of the secondary walls. Tracheids have no perforation plates.
Lysosomes
A simple description of lysosomes is that they are tiny sacs filled with fluid containing enzymes (i.e. proteins that act as biological catalysts) which enable the cell to process its nutrients and are also responsible for destroying the cell after it has died.
- Lysosomes are the main sites of digestion, that is the break-down of structures, within cells.
There are, however, some circumstances (diseases/conditions) in which lysosomes begin to 'break-down' living cells - not just useless parts of cells or potentially harmful structures. - A defining characteristic of lysosomes is that each one is bounded by only a single membrane.
What is a Lysosome ?
Definition:
A lysosome is a type of membrane-bound organelle that is present in animal cells.
Ranging in diameter from approx. 50nm to 1 μm§, lysosomes have a single outer membrane consisting of a phospholipid bilayer and contain acid hydrolases which are enzymes capable of breaking-down macromolecules.
Ranging in diameter from approx. 50nm to 1 μm§, lysosomes have a single outer membrane consisting of a phospholipid bilayer and contain acid hydrolases which are enzymes capable of breaking-down macromolecules.
§
Frog Anatomy and Dissection
In the lab, you will be spending a few days, dissecting the frog. Periodically, your instructor may pause to show you illustrations, diagrams or videos of procedures. This page is additional information that may be given to you in class as you perform the dissection.
Vomarine and Maxillary Teeth: Used for holding prey
Internal Nares (nostrils) breathing
Eustachian Tubes: equalize pressure in inner ear
Glottis : Tube leading to the lungs
Esophagus: Tube leading to the stomach
Tongue: Front attached, aids in grabbing prey
Tympanic Membrane: eardrum, located behind eyes
Nictitating Membrane: clear eyelid, protects the eye
Internal Nares (nostrils) breathing
Eustachian Tubes: equalize pressure in inner ear
Glottis : Tube leading to the lungs
Esophagus: Tube leading to the stomach
Tongue: Front attached, aids in grabbing prey
Tympanic Membrane: eardrum, located behind eyes
Nictitating Membrane: clear eyelid, protects the eye
Handouts on the Frog Dissection:
Frog External Anatomy
Frog Digestive and Urogenital System
Frog Brain and Bones
Frog Digestive and Urogenital System
Frog Brain and Bones
The Mouth
What is Biological Classification?
It is defined as a process of giving hierarchy of categories by scientific procedure based on features of organisms and arranging them into different groups.
Need for Biological Classification:
• To study and include each organism along with its identification and habitat.
• To establish the relationship among different organisms and to know about their evolution.Objectives of Classification are quite similar to needs of biological classification. There are basically three types of Biological Classification which can be categorized as artificial, natural and phylogenetic.
• To study and include each organism along with its identification and habitat.
• To establish the relationship among different organisms and to know about their evolution.Objectives of Classification are quite similar to needs of biological classification. There are basically three types of Biological Classification which can be categorized as artificial, natural and phylogenetic.
What is Artificial Classification?
Artificial Classification uses form, shape as prominent features for grouping organisms. Animals were also classified on basis of red blood cells, habitat such as land, water or air. They were also classified on their basis to fly or not to fly. This system is relatively easy to follow.
Mustard Plant Types
White or yellow, black, and brown are the three basic types of mustard plants cultivated across the globe. These plants are cultivated for vegetable, oil, seed, condiment, green manure, and even for fodder purposes.Mustard plants correspond to various plant species in the genera Brassica and Sinapis, and are known to reach maturity very fast. These plants are very beneficial, as almost every part of the plant is useful to man.
The leaves (mustard greens) and tender stems can be boiled and consumed as vegetables, while the tiny mustard seeds can be used as spice. Moreover, the seeds can also be used to prepare mustard condiments, mustard oil, etc.condiments, mustard oil, etc.
Types of Mustard Plants
Mustard plants can be divided into three types: white (or yellow), black, or brown. All these types have the same properties, and vary only in their strengths; white or yellow being the strongest, black next, and then brown. Let us learn more about these mustard plant varieties.
White Mustard (Sinapis alba)
The scientific classification of white mustard is as follows:
Kingdom: Plantae
Order: Brassicales
Family: Brassicaceae
Genus: Sinapis
Species: S. alba
White mustard or Sinapis alba is an annual plant that is grown for its mustard seeds. It is also valued for the green manure and fodder crop it makes. This crop is believed to have originated in the Mediterranean region, however, today it grows wild in the Middle East, Mediterranean, Europe, North Africa, and has also spread to different parts of the world by long cultivation.
This plant blooms between the months of February and March, and exhibits formation of pretty yellow flowers, which conduce to the formation of hairy pods. Each of these pods contain about half a dozen seeds, which are harvested before the pods ripen and burst.
White mustard seeds are hard round seeds (1-1.5 millimeter in diameter), with their color ranging from beige to yellow to light brown. They can be added to a plethora of dishes, and when ground and mixed with other ingredients, they make lovely condiments. Their pungent flavor can be attributed to the sinalbin (a glucosinolate) content in them. White mustard contains fewer volatile oils, which are responsible for its milder flavor.
Brown mustard (Brassica juncea)
The scientific classification of brown mustard is as follows:
Kingdom: Plantae
Order: Brassicales
Family: Brassicaceae
Genus: Brassica
Species: B. juncea
Brown mustard or Brassica juncea is also known as the Indian mustard, leaf mustard, or even mustard greens. It originated from the foothills of the Himalayas and is grown commercially today in Canada, UK, US, and Denmark. The sub-varieties of this species include Southern Giant Curled Mustard, which bears semblance to a headless cabbage (like kale), but with a horseradish-mustard flavor.
This plant is cultivated by farmers for green manure, whereby, it acts as mulch and prevents weeds from growing between crops. If grown for green manure, once these plants have grown sufficiently, they are cut down from the base and left to wither away. Their natural disintegration into the soil makes them a suitable mulch for the next crop being grown.
Moreover, in hazardous waste sites, brown mustard plant is used to discard heavy metals from the soil. This plant has a high tolerance level for these substances and stores heavy metal in its cells. The plants are then harvested and disposed off appropriately.
Black mustard (Brassica nigra)
The scientific classification of black mustard is as follows:
Kingdom: Plantae
Order: Brassicales
Family: Brassicaceae
Genus: Brassica
Species: B. nigra
The black mustard plant is believed to be native to the southern Mediterranean region of Europe. This plant is grown in Chile, US, Argentina, and some European countries. However, Canada is the leading mustard producer in the international market, producing about 90% of the world's mustard seeds.
Brassica nigra is cultivated as a vegetable in Ethiopia, where its leaves and stems are cooked and consumed. This plant can grow to a height of 2-8 feet, and develops small yellow flowers. Moreover, the leaves of this plant are covered in small hair. These leaves wilt during the day, however, recover at night.
The seeds of this mustard plant variety are hard and vary in color from dark brown to black. They have no aroma, however, are quite flavorful and are commonly used in Indian cuisine. These seeds contain a substantial amount of fatty oil, which is extracted and used in Indian cooking.
Mustard plants are cultivated and loved for their mustard greens, cooking oil, seeds, and condiments. So, the next time you apply mustard sauce on your hot dog, don't forget to remember these lovely plants that produce them!
The leaves (mustard greens) and tender stems can be boiled and consumed as vegetables, while the tiny mustard seeds can be used as spice. Moreover, the seeds can also be used to prepare mustard condiments, mustard oil, etc.condiments, mustard oil, etc.
Types of Mustard Plants
Mustard plants can be divided into three types: white (or yellow), black, or brown. All these types have the same properties, and vary only in their strengths; white or yellow being the strongest, black next, and then brown. Let us learn more about these mustard plant varieties.
White Mustard (Sinapis alba)
The scientific classification of white mustard is as follows:
Kingdom: Plantae
Order: Brassicales
Family: Brassicaceae
Genus: Sinapis
Species: S. alba
White mustard or Sinapis alba is an annual plant that is grown for its mustard seeds. It is also valued for the green manure and fodder crop it makes. This crop is believed to have originated in the Mediterranean region, however, today it grows wild in the Middle East, Mediterranean, Europe, North Africa, and has also spread to different parts of the world by long cultivation.
This plant blooms between the months of February and March, and exhibits formation of pretty yellow flowers, which conduce to the formation of hairy pods. Each of these pods contain about half a dozen seeds, which are harvested before the pods ripen and burst.
White mustard seeds are hard round seeds (1-1.5 millimeter in diameter), with their color ranging from beige to yellow to light brown. They can be added to a plethora of dishes, and when ground and mixed with other ingredients, they make lovely condiments. Their pungent flavor can be attributed to the sinalbin (a glucosinolate) content in them. White mustard contains fewer volatile oils, which are responsible for its milder flavor.
Brown mustard (Brassica juncea)
The scientific classification of brown mustard is as follows:
Kingdom: Plantae
Order: Brassicales
Family: Brassicaceae
Genus: Brassica
Species: B. juncea
Brown mustard or Brassica juncea is also known as the Indian mustard, leaf mustard, or even mustard greens. It originated from the foothills of the Himalayas and is grown commercially today in Canada, UK, US, and Denmark. The sub-varieties of this species include Southern Giant Curled Mustard, which bears semblance to a headless cabbage (like kale), but with a horseradish-mustard flavor.
This plant is cultivated by farmers for green manure, whereby, it acts as mulch and prevents weeds from growing between crops. If grown for green manure, once these plants have grown sufficiently, they are cut down from the base and left to wither away. Their natural disintegration into the soil makes them a suitable mulch for the next crop being grown.
Moreover, in hazardous waste sites, brown mustard plant is used to discard heavy metals from the soil. This plant has a high tolerance level for these substances and stores heavy metal in its cells. The plants are then harvested and disposed off appropriately.
Black mustard (Brassica nigra)
The scientific classification of black mustard is as follows:
Kingdom: Plantae
Order: Brassicales
Family: Brassicaceae
Genus: Brassica
Species: B. nigra
The black mustard plant is believed to be native to the southern Mediterranean region of Europe. This plant is grown in Chile, US, Argentina, and some European countries. However, Canada is the leading mustard producer in the international market, producing about 90% of the world's mustard seeds.
Brassica nigra is cultivated as a vegetable in Ethiopia, where its leaves and stems are cooked and consumed. This plant can grow to a height of 2-8 feet, and develops small yellow flowers. Moreover, the leaves of this plant are covered in small hair. These leaves wilt during the day, however, recover at night.
The seeds of this mustard plant variety are hard and vary in color from dark brown to black. They have no aroma, however, are quite flavorful and are commonly used in Indian cuisine. These seeds contain a substantial amount of fatty oil, which is extracted and used in Indian cooking.
Mustard plants are cultivated and loved for their mustard greens, cooking oil, seeds, and condiments. So, the next time you apply mustard sauce on your hot dog, don't forget to remember these lovely plants that produce them!
Taxonomy
Taxonomy is a hierarchical system for classifying and identifying organisms. This system was developed by Swedish scientist Carolus Linnaeus in the 18th century.
Binomial Nomenclature
Linnaeus's taxonomy system has two main features that contribute to its ease of use in naming and grouping organisms. The first is the use of binomial nomenclature. This means that an organism's scientific name is comprised of a combination of two terms. These terms are the genus name and the species or epithet. Both of these terms are italicized and the genus name is also capitalized. For example, the scientific name for humans is Homo sapiens . The genus name is Homo and the species is sapiens . These terms are unique and no other species can have this same name.
Binomial Nomenclature
Linnaeus's taxonomy system has two main features that contribute to its ease of use in naming and grouping organisms. The first is the use of binomial nomenclature. This means that an organism's scientific name is comprised of a combination of two terms. These terms are the genus name and the species or epithet. Both of these terms are italicized and the genus name is also capitalized. For example, the scientific name for humans is Homo sapiens . The genus name is Homo and the species is sapiens . These terms are unique and no other species can have this same name.
Cell organization
Cells are divided into several compartments, each with a characteristic structure,biochemical composition, and function (see illustration). These compartments arecalled organelles. They are delimited by membranes composed of phospholipidbilayers and a number of proteins specialized for each type of organelle. Alleukaryotic cells have a nucleus surrounded by a nuclear envelope, and a plasmamembrane that borders the whole cell. Most eukaryotic cells also haveendoplasmic reticulum, a Golgi apparatus, lysosomes, mitochondria, andperoxisomes. Plant cells have chloroplasts for photosynthesis in addition to theorganelles that both they and animal cells possess. These organelles aresuspended in a gellike cytoplasmic matrix composed of three types of proteinpolymers called actin filaments, microtubules, and intermediate filaments. Inaddition to holding the cell together, the actin filaments and microtubules act astracks for several different types of motor proteins that are responsible for cellmotility and organelle movements within the cytoplasm.
Section through an animal cell showing the majorcomponents visible by electron microscopy
A major challenge in the field of cell biology is to learn how each organelle andthe cytoplasmic matrix are assembled and distributed in the cytoplasm. This is avery complex process since cells consist of more than 2000 different proteinmolecules together with a large number of lipids, polysaccharides, and nucleicacids, including both deoxyribonucleic acid (DNA) and many different types ofribonucleic acid (RNA). See Nucleic acid
Active Transport Across Cell Membranes
| There are numerous situations in living organisms when molecules move across cell membranes from an area of lower concentration toward an area of higher concentration. This is counter to what would be expected and is labeled "active transport". There is a very strong tendency for molecules to move from higher concentration to low, just based on thermal energy. Molecules at normal temperatures have very high speeds and random motions. For example, water molecules at 20°C have an effective or rms speed of over 600 m/s or over 1400 miles/hr! This motion from areas of high concentration to low is called diffusion. There are times when membranes are impermeable to some molecules because of their size, polarity, etc. and only the smaller solvent molecules like water molecules will move across the membrane. This is called osmosis, and the tendency to transport the solvent molecules is quantified in terms of osmotic pressure.
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Cell Cycle and Cell Division
The study of the cell cycle focuses on mechanisms that regulate the timing and frequency of DNA duplication and cell division. As a biological concept, the cell cycle is defined as the period between successive divisions of a cell. During this period, the contents of the cell must be accurately replicated. Microscopists had known about cell division for more than one hundred years, but not until the 1950s, through the pioneering work of Alma Howard and Stephen Pelc, did they become aware that DNA replication took place only at a specific phase of the cell cycle and that this phase was clearly separated from mitosis. Howard and Pelc's work in the broad bean, Vicia faba, revealed that the cell goes through many discrete phases before and after cell division. From this understanding, scientists then identified the four characteristic phases of the cell cycle: mitosis (M), gap 1 (G1), DNA synthesis (S), and gap 2 (G2). The study of these phases, the proteins that regulate them, and the complex biochemical interactions that stop or start DNA replication and cell division (cytokinesis) are the primary concerns of cell cycle biologists.
The most significant progress in this research field came with the demonstration that specific protein complexes involving cyclins were critical for regulating the passage of cells through the cell cycle. These early observations came from biological studies of the cells of rapidly dividing fertilized frog eggs as well as mutant yeast cells that could not divide. The observations suggested that regulation of the cell cycle is conserved throughout eukaryotes, which has since proved to be the case. The mechanism of division in bacteria differs from that of eukaryotes, and the control of their cell cycle is also somewhat different, although again it is linked with DNA replication.
The most significant progress in this research field came with the demonstration that specific protein complexes involving cyclins were critical for regulating the passage of cells through the cell cycle. These early observations came from biological studies of the cells of rapidly dividing fertilized frog eggs as well as mutant yeast cells that could not divide. The observations suggested that regulation of the cell cycle is conserved throughout eukaryotes, which has since proved to be the case. The mechanism of division in bacteria differs from that of eukaryotes, and the control of their cell cycle is also somewhat different, although again it is linked with DNA replication.Understanding Plant Names—Binomial Nomenclature Explained
Just starting out, many novice gardeners walk into a garden center and ask for a plant by the name they first heard it called by, maybe a devil's ivy or a purple heart-leaf plant. Imagine their surprise, then, when the helpful garden center employee brings them a plant that looks nothing like the one they were expecting.
The problem isn't with either the gardener or the employee. More likely, it's a communication issue-many plants share the same common names, or the same plant might be known by several different common names in various regions of the world.The solution to the naming issue was actually presented centuries ago, when the system of binomial nomenclature was developed the Swedish botanist Carolus Linnaeus and then widely adopted. This system relied on two-part Latin names for each plant. The first name would describe the plant's genus and the second its species. The global adoption of binomial nomenclature meant that people asking for a Dracaena draco in Indonesia would be assured they are talking about the same plant as people discussing Dracaena draco in London or New York or Nepal.
The problem isn't with either the gardener or the employee. More likely, it's a communication issue-many plants share the same common names, or the same plant might be known by several different common names in various regions of the world.The solution to the naming issue was actually presented centuries ago, when the system of binomial nomenclature was developed the Swedish botanist Carolus Linnaeus and then widely adopted. This system relied on two-part Latin names for each plant. The first name would describe the plant's genus and the second its species. The global adoption of binomial nomenclature meant that people asking for a Dracaena draco in Indonesia would be assured they are talking about the same plant as people discussing Dracaena draco in London or New York or Nepal.
While it undoubtedly furthered science, binomial nomenclature is infinitely helpful to the amateur biologist or plant collector. It reduces confusion and guarantees you'll get the plant you want. Thus, it's strongly advised that beginners to gardening begin to learn the Latin names of plants as soon as possible.
Aside from reducing confusing, the nomenclature system is valuable because it also provides a great deal of information about the plant you are buying. A typical Latin plant name will have two parts: the genus and species, as mentioned. When written, the genus should always be capitalized and the species will be lowercase. However, beyond that, there may be other words that yeild more information. For example:Dracaena deremensis 'Warneckii'
In this case, the third word describes the cultivar of the main species. So this plant would be a D. deremensis 'Warneckii'cultivar. A cultivar is simply a strain of a species that has been carefully bred to encourage certain traits that are naturally present in the species. For example, a breeder might, over time, breed a certain plant to encourage larger, green leaves, crossing and recrossing parents with larger, green leaves back on themselves. Over time, once this trait has been stabilized and it's possible to reliably produce spcies of this plant with larger, green leaves, a cultivar name might be assigned to the plants. Note that the cultivar name is surrounded in single quotes and no italicized, whereas the genus and species names are still italicized.You might also see a plant name that looks like this:
Citrus x citrofortunella mitis
This formulation, with an x in the name, denotes a hybridized plant. In this case, the plant is a hybrid between the mandarin orange and kumquat, within the genus x citrofortunella. Hybrids are almost always created by breeders looking to stengthen and reinforce certain desirable qualities in parent plants of different species. It's important to note that only closely related species can be successfully crossed to produce new hybrids, and even then, in most cases the offspring will be sterile or will bear seeds that don't produce true to the parent (they might grow plants that are strongly associated with one of the parent species of the other). True hybrids in nature are exceedingly rare.
It's valuable to note that, while this system is used to classify all plants and animals worldwide, the naming conventions behind orchids can be somewhat more complex. This is due in part to the sheer number of orchid species and their complexity, and the very active breeding community that has, over the century, produced tens of thousands of named cultivars and hybrids.
Levels of Organization of Living Things
The biological levels of organization range from a single organelle all the way up to the biosphere in a highly structured hierarchy.
KEY POINTS
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The atom is the smallest and most fundamental unit of matter, and the bonding of at least two atoms or more form molecules.
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The simplest level of organization for living things is a single organelle, which is composed of aggregates of macromolecules.
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The highest level of organization for living things is the biosphere; it encompasses all other levels.
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The biological levels of organization of living things arranged from the simplest to most complex are: organelle, cells, tissues, organs, organ systems, organisms, populations, communities, ecosystem, and biosphere.
- The atom is the smallest and most fundamental unit of matter, and the bonding of at least two atoms or more form molecules.
- The simplest level of organization for living things is a single organelle, which is composed of aggregates of macromolecules.
- The highest level of organization for living things is the biosphere; it encompasses all other levels.
- The biological levels of organization of living things arranged from the simplest to most complex are: organelle, cells, tissues, organs, organ systems, organisms, populations, communities, ecosystem, and biosphere.
TERMS
- polymerization
The chemical process, normally with the aid of a catalyst, to form a polymer by bonding together multiple identical units (monomers).
- molecule
The smallest particle of a specific compound that retains the chemical properties of that compound; two or more atoms held together by chemical bonds.
- macromolecule
a very large molecule, especially used in reference to large biological polymers(e.g. nucleic acids and proteins)
- polymerizationThe chemical process, normally with the aid of a catalyst, to form a polymer by bonding together multiple identical units (monomers).
- moleculeThe smallest particle of a specific compound that retains the chemical properties of that compound; two or more atoms held together by chemical bonds.
- macromoleculea very large molecule, especially used in reference to large biological polymers(e.g. nucleic acids and proteins)
- polymerization
Levels of Organization of Living Things
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Living things are highly organized and structured, following a hierarchy that can be examined on a scale from small to large. The atom is the smallest and most fundamental unit of matter. It consists of a nucleus surrounded by electrons. Atoms form molecules which are chemical structures consisting of at least two atoms held together by one or more chemical bonds. Many molecules that are biologically important are macromolecules, large molecules that are typically formed by polymerization (a polymer is a large molecule that is made by combining smaller units called monomers, which are simpler than macromolecules).
- Living things are highly organized and structured, following a hierarchy that can be examined on a scale from small to large. The atom is the smallest and most fundamental unit of matter. It consists of a nucleus surrounded by electrons. Atoms form molecules which are chemical structures consisting of at least two atoms held together by one or more chemical bonds. Many molecules that are biologically important are macromolecules, large molecules that are typically formed by polymerization (a polymer is a large molecule that is made by combining smaller units called monomers, which are simpler than macromolecules).
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