Growth And Development “Development” and “growth” are sometimes used interchangeably in conversation, but in a botanical sense, they describe separate events in the organization of the mature plant body.
Developmentis the progression from earlier to later stages in maturation, e.g. a fertilized egg develops into a mature tree. It is the process whereby tissues, organs, and whole plants are produced. It involves: growth, morphogenesis (the acquisition of form and structure), and differentiation. The interactions of the environment and the genetic instructions inherited by the cells determine how the plant develops.
Growth is the irreversible change in size of cells and plant organs due to both cell divisionandenlargement. Enlargement necessitates a change in the elasticity of the cell walls together with an increase in the size and water content of the vacuole. Growth can be determinate—when an organ or part or whole organism reaches a certain size and then stops growing—orindeterminate—when cells continue to divide indefinitely. Plants in general have indeterminate growth.
Differentiation is the process in which generalized cells specialize into the morphologically and physiologically different cells . Since all of the cells produced by division in the meristems have the same genetic make up, differentiation is a function of which particular genes are either expressed or repressed. The kind of cell that ultimately develops also is a result of its location: Root cells don't form in developing flowers, for example, nor do petals form on roots.
Mature plant cells can be stimulated under certain conditions to divide and differentiate again, i.e. to dedifferentiate. This happens when tissues are wounded, as when branches break or leaves are damaged by insects. The plant repairs itself bydedifferentiating parenchyma cells in the vicinity of the wound, making cells like those injured or else physiologically similar cells.
Plants differ from animals in their manner of growth. As young animals mature, all parts of their bodies grow until they reach a genetically determined size for each species. Plant growth, on the other hand, continues throughout the life span of the plant and is restricted to certain meristematic tissue regions only. This continuous growth results in:
Two general groups of tissues, primaryandsecondary.
Two body types, primaryand secondary.
Apicaland lateral meristems.
Apical meristems, or zones of cell division, occur in the tips of both roots, stems of all plants, and are responsible for increases in the length of the primary plant body as the primary tissues differentiate from the meristems. As the vacuoles of the primary tissue cells enlarge, the stems and roots increase in girth until a maximum size (determined by the elasticity of their cell walls) is reached. The plant may continue to grow in length, but no longer does it grow in girth. Herbaceous plants with only primary tissues are thus limited to a relatively small size.
Woody plants, on the other hand, can grow to enormous size because of the strengthening and protective secondary tissues produced by lateral meristems, which develop around the periphery of their roots and stems. These tissues constitute the secondary plant body.
Heredity And Variability Heredity refers to the genetic transmission of traits from parents to offspring. Heredity helps explain why children tend to resemble their parents, as well as how a genetic disease runs in a family. Some genetic conditions are caused by mutations in a single gene. These conditions are usually inherited in one of several straightforward patterns, including autosomal dominant, autosomal recessive, X-linked dominant, X-linked recessive, codominant, and mitochondrial inheritance patterns. Complex disorders and multifactorial disorders are caused by a combination of genetic and environmental factors. These disorders may cluster in families, but do not have a clear-cut pattern of inheritance.
Evolution : a process of development in which an organ or organism becomes more and more complex by the differentiation of its parts; a continuous and progressive change according to certain laws and by means of resident forces
bathmic or orthogenic evolution : evolution due to something in the organism itself independent of environment
convergent evolution : the appearance of similar forms and/or functions in two or more lines not sufficiently related phylogenetically to account for the similarity. The concept that chance reigns supreme may ring less true when it comes to complex behaviors. A study of the similarities between the webs of different Tetragnatha spider species on different Hawaiian Islands provides fresh evidence that behavioral tendencies can actually evolve rather predictably, even in widely separated places. The spiders' webs vary significantly, with tissue-like 'sheet webs', disorganized cobwebs and spiral-shaped 'orb webs' as three of the most common types. Each species had its own characteristic type of web. But the scientists found that in several cases, separate species of Tetragnatha spiders on different islands constructed extremely similar orb webs, right down to the number of spokes, and the lengths and densities of the sticky spiral that captures bugs. Was this an example of similar environments producing the same complex behavior, or did the spiders with corresponding webs share a common ancestor? The tree that linked spiders through their web-constructing behavior proved highly improbable as it was very complicated, and contradicted the relationships suggested by their DNA. It is likely that similar forest types support similar mixes of prey, which could elicit similar web structures. Previous research has found that physical traits, for example legs or wings, can arise independently in similar environmental conditions. And various groups have looked at the evolution of simple behaviors, such as where species locate themselves within a habitat, like a branch or lake. But the evolution of complex behaviors is less well understood : predictable evolutionary convergence of behavior applies far beyond spiders, and happens more often then some believe
- emergent evolution : the assumption that each step in evolution produces something new and something that could not be predicted from its antecedents.
- organic evolution : the origin and development of species; the theory that existing organisms are the result of descent with modification from those of past times.
- parallel evolution : the independent evolution of similar structures in two or more rather closely related organisms
o halmatogenesis / salutatory variation : a sudden alteration of type from one generation to another
- darwinism / darwinian theory : the theory of evolution by Charles Robert Darwin according to which higher organisms have developed from lower ones through the influence of natural selection
o adaptive plasticity in response to environmental pressures : snake populations that persistently encounter large prey may accumulate gene mutations that specify a large head size, or head growth may be increased in individual snakes to meet local demands (adaptive developmental plasticity).
- monogenesis : the theory of evolution according to which the course of evolution is fixed and predetermined by law, no place being left for chance
- an adaptations programme has dominated evolutionary thought in England and the United States during the past 40 years. It is based on faith in the power of natural selection as an optimizing agent. It proceeds by breaking an organism into unitary 'traits' and proposing an adaptive story for each considered separately. Trade-offs among competing selective demands exert the only brake upon perfection; non-optimality is thereby rendered as a result of adaptation as well. Some criticize this approach and attempt to reassert a competing notion (long popular in continental Europe) that organisms must be analyzed as integrated wholes, with Bauplane so constrained by phyletic heritage, pathways of development and general architecture that the constraints themselves become more interesting and more important in delimiting pathways of change than the selective force that may mediate change when it occurs. Some fault the adaptationist programme for its failure to distinguish current utility from reasons for origin (male tyrannosaurs may have used their diminutive front legs to titillate female partners, but this will not explain why they got so small); for its unwillingness to consider alternatives to adaptive stories; for its reliance upon plausibility alone as a criterion for accepting speculative tales; and for its failure to consider adequately such competing themes as random fixation of alleles, production of non-adaptive structures by developmental correlation with selected features (allometry, pleiotropy, material compensation, mechanically forced correlation), the separability of adaptation and selection, multiple adaptive peaks, and current utility as an epiphenomenon of non-adaptive structures. Some support Darwin's own pluralistic approach to identifying the agents of evolutionary change
- the theory of intelligent design (ID)makes the claim that the existence of complex systems and phenomena, lacking any justification for their existence that is known to us, implies that such systems exist as the purposeful result of the activity of a powerful, conscious being that designed the visible complexity into them. This is not a scientific explanation, as it posits the existence of something that cannot be tested or demonstrated by experiment, but must be taken on faith. The contrast between the theory of intelligent design and the theory of special creation is that the latter names the designer "God" and declares the story in the biblical book of Exodus as the whole truth, whereas the former does not name the designer nor does it declare any particular story of the designer's works and actions to be historical truth. However, both of these theories are theology, not biology, and while not identical, are both out of place in a life science journal. Theologians, and even scientists, are entitled to logically debate questions of faith surrounding the problems of first causes, complexity, the existence of evil, and so forth, but not in scientific publications. Albert Einstein is quoted as having said, "Science without religion is lame; religion without science is blind." Let us be clear, however: science is about knowledge gained by hypothesis testing, and religion is about faith gained from reason, inspiration, and introspection. We must keep them properly separated to understand the difference between that which we can know and that which we must choose, or choose not, to believe.
- first proposed by W.D. Hamilton in 1964, the theory of kin selection holds that altruistic cooperative behavior preferentially directed at helping a relative is favored because it helps that relative do better and reproduce, which indirectly helps the cooperator to pass on its genes. Generating siderophores is costly to producer Pseudomonas aeruginosa (cooperators), but others around it can use the siderophores to their own benefit without paying the price (cheaters). When relatedness is high, the cooperators spread to fixation and take over; and when relatedness is low, the cheaters spread to take over, meaning that higher relatedness had a tendency to favor selection for more altruism or cooperation. Another more subtle effect of kin selection is the scale of competition—whether competition is local (competition between close relatives) or global (competition between unrelated bacteria of the same species). Relatedness increases cooperation, so that over time, a localized group of highly related organisms emerges. But eventually, these would also become the closest competitors in the local area, so they were the ones you had to compete with for spots in the gene pool in the next generation. The experimental effects of relatedness on the scale of competition explained > 90% of the variation in the frequency of cooperators versus cheaters at the end of the experiment. The work has implications for social insects : if individual insects are close relatives but are going be dispersing to some other area, or maybe foraging in different areas or looking in different areas for mates, then the scale at which competition might take place is going to vary quite a bit depending on the ecology of that particular insect.
Selection Selection generally refers to the pressures on crops and organisms to evolve. These pressures include natural selection, and, in eukaryotic cells that reproduce sexually, sexual selection. Certain phenotypic traits (characteristics of an organism)—or, on a genetic level, alleles of genes—segregate within a population, where individuals with aadaptive advantages or traits tend to succeeded more than their peers when they reproduce, and so contribute more ooffspring to the succeeding generation. When these traits have a genetic basis, selection can increase the prevalence of those traits, because offspring inherit them from their parents. When selection is intense and persistent, adaptive traits become universal to the population or species, which may then be said to have evolved.
Whether or not selection takes place depends on the conditions in which the individuals of a species find themselves. Adults, juveniles, embryos, and gameteeggs and sperm all undergo selection. Factors fostering selection include sexual selection, primarily caused by mate choice in the mating phase of sexual reproduction, limits on resources (nourishment, habitat space, mates) and the existence of threats (predators, disease, adverse weather). Biologists often refer to such factors as selective or evolutionary pressures.
Natural selection has, since the 1930s, included sexual selection because biologists at the time did not think it was of great importance though it has become to be seen as more important in the 21st Century.Other subcategories of natural selection include ecological selection, stabilizing selection, disruptive selection and selection. Selective can be seen in the breeding of dogs, and the domestication of farm animals and crops, now commonly known as selective breeding.
Selection is hierarchically classified into natural and artificial selection. Natural selection is further sub classified into ecological and sexual selection
Selection occurs only when the individuals of a population are diverse in their characteristics—or more specifically when the traits of individuals differ with respect to how well they equip them to survive or exploit a particular pressure. In the absence of individual variation, or when variations are selectively neutral, selection does not occur.
Meanwhile, selection does not guarantee that advantageous traits or alleles become prevalent within a population. Another process of gene frequency alteration in a population is called genetic drift, which acts over genes that are not under selection. But, this drift can't overcome natural selection itself, as it is a 'random sampling' process and Natural Selection is actually an evaluative force. In the face of selection, even a so-called deleterious allele may become universal to the members of a species. This is a risk primarily in the case of "weak" selection (e.g., an infectious disease with only a low mortality rate) or small populations.
Though deleterious alleles may sometimes become established, selection may act "negatively" as well as positively. Negative selection or purifying selection decreases the prevalence of traits that diminish individuals' capacity to succeed reproductively (i.e., their fitness), while positive selection increases the prevalence of adaptive traits.
Evolutionary Development Charles Darwin's theory of evolution builds on three principles: natural selection, heredity, and variation. At the time that Darwin wrote, the principles underlying heredity and variation were poorly understood. In the 1940s, however, biologists incorporated Gregor Mendel's principles of genetics to explain both, resulting in the modern synthesis. It was not until the 1980s and 1990s, however, when more comparative molecular sequence data between different kinds of organisms was amassed and detailed, that an understanding of the molecular basis of the developmental mechanisms began to form.
Currently, it is well understood how genetic mutation occurs. However, developmental mechanisms are not understood sufficiently to explain which kinds of phenotypic variation can arise in each generation from variation at the genetic level. Evolutionary developmental biology studies how the dynamics of development determine the phenotypic variation arising from genetic variation and how that affects phenotypic evolution (especially its direction). At the same time evolutionary developmental biology also studies how development itself evolves.
Thus the origins of evolutionary developmental biology come both from an improvement in molecular biology techniques as applied to development, and from the full appreciation of the limitations of classic neo-Darwinism as applied to phenotypic evolution. Some evo-devo researchers see themselves as extending and enhancing the modern synthesis by incorporating the findings of molecular genetics and developmental biology into an extended evolutionary synthesis.
Evolutionary developmental biology can be distinguished from earlier approaches to evolutionary theory by its focus on a few crucial ideas. One of these is modularity: as has been long recognized, plants and animal bodies are modular: they are organized into developmentally and anatomically distinct parts. Often these parts are repeated, such as fingers, ribs, and body segments. Evo-devo seeks the genetic and evolutionary basis for the division of the embryo into distinct modules, and for the partly independent development of such modules.
The statisticianRonald Fisher (1890 – 1962) helped to form the modern evolutionary synthesis of Mendelian genetics and natural selection.
J. B. S. Haldane (1892 – 1964) helped to create the field of population genetics.
Microbiology has recently developed into an evolutionary discipline. It was originally ignored due to the paucity of morphological traits and the lack of a species concept in microbiology. Now, evolutionary researchers are taking advantage of a more extensive understanding of microbial physiology, the ease of microbial genomics, and the quick generation time of some microbes to answer evolutionary questions. Similar features have led to progress in viral evolution, particularly for bacteriophages.
Many biologists have contributed to our current understanding of evolution. Although the term had been used sporadically starting at the turn of the century, evolutionary biology in a disciplinary sense gained currency during the period of "the evolutionary synthesis" (Smocovitis, 1996). Theodosius Dobzhansky and E. B. Ford were important in the establishment of an empirical research programmer for evolutionary biology as were theorists Ronald Fisher, Sewall Wright and J. S. Haldane. Ernst Mayr, George Gaylord Simpson and G. Ledyard Stebbins were also important discipline-builders during the modern synthesis, in the fields of systematics, palaeontology and botany, respectively. Through training many future evolutionary biologists, James Crow,Richard Lewontin, Dan Hartl, Marcus Feldman, and Brian Charlesworth have also made large contributions to building the discipline of evolutionary biology.
Organismes and environment
State of ecosystems, habitats and species
The expansion of humans activities into the natural environment, manifested by urbanization, recreation, industrialization, and agriculture, results in increasing uniformity in landscapes and consequential reduction, disappearance, fragmentation or isolation of habitats and landscapes.
It is evident that the increasing exploitation of land for human use greatly reduces the area of each wildlife habitat as well as the total area surface throughout Europe. The consequences are:
A decreased species diversity, due to reduced habitable surface area which corresponds to a reduced "species carrying capacity".
The reduction of the size of habitats also reduces the genetic diversity of the species living there. Smaller habitats can only accommodate smaller populations, this results in an impoverished gene pool.
The reduction of genetic resources of a species diminishes its flexibility and evolutionary adaptability to changing situations. This has significant negative impacts on its survival.
The conditions under which the reduction of habitats often occur prevent living organisms making use of their normal ways to flee their threatened habitat. Those escape routes include migration to other habitats, adaption to the changing environment, or genetic interchange with populations in nearby habitats. Particular concern is:
The abrupt nature of human intervention; human projects are planned and implemented on a much shorter time scale than natural processes;
Furthermore human intervention, such as the construction of buildings, motorways or railways results in the fragmentation of habitats, which strongly limits the possibility for contact or migration among them;
In extreme cases, even the smallest, narrowest connections between habitats are broken off. Such isolation is catastrophic for life in the habitat fragments.
Loss of Species of Fauna and Flora
Although relatively few species of Europe's fauna and flora have actually become extinct during this century, the continent's biodiversity is affected by decreasing species numbers and the loss of habitats in many regions. Approximately 30 % of the vertebrates and 20 % of the higher plants are classified as "threatened". Threats are directly linked to the loss of habitats due to destruction, modification and fragmentation of ecosystems as well as from overuse of pesticides and herbicides, intensive farming methods, hunting and general human disturbance. The overall deterioration of Europe's air and water quality add to the detrimental influence.
Europe's natural environment is inextricably linked with agriculture and forestry. Since agriculture traditionally depends on sound environmental conditions, farmers have a special interest in the maintenance of natural resources and for centuries maintained a mosaic of landscapes which protected and enriched the natural environment.
As a result of needs for food production since the 1940s, policies have encouraged increased pro- diction through a variety of mechanisms, including price support, other subsidies and support for research and development. The success achieved in agricultural production has however entailed increased impact on the environment.
Modern agriculture is responsible for the loss of much wildlife and their habitats in Europe, through reduction and fragmentation of habitats and wildlife populations. The drainage of wetlands, the destruction of hedgerows and the intensive use of fertilizers and pesticides can all pose a threat to wildlife. Highly specialized monoculture are causing significant loss in species abundance and diversity. On the other hand, increased production per hectare in intensive areas, raising of livestock volume, and lower prices for agricultural products also caused marginalization of agricultural land, changing the diversity of European landscapes into the direction of two main types: Intensive Agriculture and Abandoned land.
Abandonment can be positive for nature, but this is not necessarily so. Land abandonment increases the risk of fire in the Mediterranean Region, causes a decline of small-scale landscape diversity and can cause decrease in species diversity.
All energy types have potential impacts on the natural environment to varying degrees at all stages of use, from extraction through processing to end use. Generating energy from any source involves making the choices between impacts and how far those impacts can be tolerated at the local and global scale. This is especially of importance for nuclear power, where there are significant risks of radioactive pollution such as at Chernobyl.
Shell Oil Company and IUCN have jointly drafted environmental regulations for oil-exploitation in Arctic areas of Siberia. Other oil companies are aware of this and use these environmental regulations voluntarily for developing oil fields.
Into the future, the sustainability of the natural environment will be improved as trends away from damaging energy uses, extractive methods reduce, and whilst real cost market forces and the polluter pays principle take effect.
The principle of the fisheries sector is towards sustainable catches of wild aquatic fauna. The principle environmental impact associated with fisheries activities is the unsustainable har- vesting of fish stocks and shellfish and has consequences for the ecological balance of the aquatic environment. The sector is in a state of "crisis", with over capacity of the fleet, overexploitation of stocks, debt, and marketing problems.
Growing aquaculture industry may increase water pollution in Western Europe, and is appearing to be a rising trend in the Mediterranean and Central/East Europe.
Fishing activities have an impact on cetaceans and there is concern that large numbers of dolphins, and even the globally endangered Monk seal, are being killed.
Compared to other land uses, forest management has the longest tradition in following sustainable principles due to which over 30% of Europe is still covered with trees. Without such an organized approach, forests are likely to have already disappeared from Europe's lowlands. However, as an economic sector, forestry has also impacted severely on the naturalness of Europe's forests: soils have been drained, pesticides and fertilizers applied, and exotic species planted. In many areas monocultures have replaced the original diverse forest composition. Monocultures are extremely sensitive to insect infestations, fires or wind, and so can lead to financial losses as well as biological decline. The inadequate afforestation practices characterize new trends in impacting on the sustainability of the natural environment.
Almost all forms of industry have an impact on the natural environment and its sustainability. The impact varies at different stages in the life cycle of a product, depending upon the raw materials used through to the final end use of the product for waste residue, re-use or recycling. Industrial accidents and war damage to industrial plants can also endanger the natural environment.
Transport and Infrastructure
Transport is perhaps the major contributor to pollution in the world today, particularly global envy- ronmental issues such as the greenhouse effect. The key impacts of transportation include frag- mentation of habitats and species and genetic populations, disruption of migration and traffic mortalities to wildlife. Since the 1970s transport has become a major consumer of non-renewable resources, 80% of oil consumption coming from road transport.
Human Impact On The Natural Environment
Main article:Environmental impact of agriculture
The environmental impact of agriculture varies based on the wide variety of agricultural practices employed around the world. Ultimately, the environmental impact depends on the production practices of the system used by farmers. The connection between emissions into the environment and the farming system is indirect, as it also depends on other climate variables such as rainfall and temperature.
There are two types of indicators of environmental impact: "means-based", which is based on the farmer's production methods, and "effect-based", which is the impact that farming methods have on the farming system or on emissions to the environment. An example of a means-based indicator would be the quality of groundwater, that is effected by the amount of nitrogen applied to the soil. An indicator reflecting the loss of nitrate to groundwater would be effect-based.
The environmental impact of agriculture involves a variety of factors from the soil, to water, the air, animal and soil diversity, plants, and the food itself. Some of the environmental issues that are related to agriculture are climate change, deforestation, genetic engineering, irrigation problems, pollutants, soil degradation, and waste.
Natural environment is of crucial importance for social and economic life. We use the living world as
a resource for food supply
an energy source
a source for recreation
a major source of medicines
natural resources for industrial products
In this respect the diversity of nature not only offers man a vast power of choice for his current needs and desires. It also enhances the role of nature as a source of solutions for the future needs and challenges of mankind.
Applied integrated sciences
Biochemistry and molecular biology (mcdb) What is the difference between biochemistry, molecular biology, and genetics?
Genetics is the most distinct of the three. It studies genes, genomics, and heredity. This can include molecular genetics, which deals directly with the DNA and it includes population genetics, which has more to do with how different alleles spread in a population.
I have yet to see a definition of molecular biology that does not overlap with biochemistry. The two are nearly identical sciences. The closest I have found to a meaningful distinction is that molecular biologists are biologists and biochemists are chemists. Molecular biologists concern themselves with the biological processes; the cells, the tissues, the organisms. Biochemists are more about the chemicals, which just happen to be in a living thing; reaction mechanisms, thermodynamics, bond angles and the like. Not that what I am saying here is universally agreed upon.
At the end of the day, the amount of overlap is massive and we are splitting hairs by saying somebody is absolutely one and not the other. One can have a degree in molecular biology, be a member of a genetics department, and look at the structural biochemistry of how a protein binds to DNA.
Biochemistry has to do with chemical properties and interactions of biological molecules. So for example we can take an isolated enzyme add substrate and measure the kinetics of a reaction in a test tube. The experiments try to isolate specific chemical properties, not necessarily mimicking cellular environment (which is most often the case).
Molecular biology has to do with biological effects of specific molecules - we add X to cell culture - do the cells die? Do they become cancerous?
Genetics looks at heritability of traits and tries to find what are the molecules that have to do with that trait. How much of susceptibility to X can be attributed to genetics? What is the gene that makes eyes blue?
In current research these disciplines closely intertwine, and it is almost impossible to publish a good paper in only one of them, without having some evidence from others. So genetics identifies the players, biochemistry says how they likely function, and molecular biology asks how this function influences biological properties of an organism.
Biochemistry focuses on the protein part of life functions. It studies the components independent of the organism.
Genetics focuses on the gene part. Usually mutants are used. So, it is organism without the component.
Molecular Biology integrates those two, as can be quite well ascertained from the "central dogma" i.e., genes-> proteins.
So, for e.g., if one is interested in studying what imparts red color to a fruit fly’s eyes, this is probably how the three would work:
A biochemist would make a puree of the fruit fly, isolate the component responsible for the eye color and characterize it.
A geneticist would look for flies that have different eye colors, and compare each of them, breed them in various combinations, observe how the traits are inherited. So essentially, one can be blissfully unaware of the chemical nature of the said component (gene/ protein) but still figure out how the trait is passed on/ affect a population.
A molecular biologist would isolate the gene, study it, and arrive at the protein therefrom.
Biochemistry is the study of chemical processes within and relating to living organisms. By controlling information flow through biochemical signaling and the flow of chemical energy through metabolism, biochemical processes give rise to the complexity of life. Molecular biology is a branch of science concerning biological activity at the molecular level. The field of molecular biology overlaps with biology and chemistry and in particular, genetics and biochemistry. and, Genetics is the study of genes, heredity, and genetic variation in living organisms. It is generally considered a field of biology, but it intersects frequently with many of the life sciences and is strongly linked with the study of information systems.
Cell Biology Cell biology is the study of cell structure and function, and it revolves around the concept that the cell is the fundamental unit of life. Focusing on the cell permits a detailed understanding of the tissues and organisms that cells compose. Some organisms have only one cell, while others are organized into cooperative groups with huge numbers of cells. On the whole, cell biology focuses on the structure and function of a cell, from the most general properties shared by all cells, to the unique, highly intricate functions particular to specialized cells.
The starting point for this discipline might be considered the 1830s. Though scientists had been using microscopes for centuries, they were not always sure what they were looking at. Robert Hooke's initial observation in 1665 of plant-cell walls in slices of cork was followed shortly by Antoine van Leeuwenhoek's first descriptions of live cells with visibly moving parts. In the 1830s two scientists who were colleagues — Schleiden, looking at plant cells, and Schwann, looking first at animal cells — provided the first clearly stated definition of the cell. Their definition stated that that all living creatures, both simple and complex, are made out of one or more cells, and the cell is the structural and functional unit of life — a concept that became known as cell theory.
As microscopes and staining techniques improved over the nineteenth and twentieth centuries, scientists were able to see more and more internal detail within cells. The microscopes used by van Leeuwenhoek probably magnified specimens a few hundredfold. Today high-powered electron microscopes can magnify specimens more than a million times and can reveal the shapes of organelles at the scale of a micrometer and below. With confocal microscopy, a series of images can be combined, allowing researchers to generate detailed three-dimensional representations of cells. These improved imaging techniques have helped us better understand the wonderful complexity of cells and the structures they form.
There are several main subfields within cell biology. One is the study of cell energy and the biochemical mechanisms that supportcell metabolism. As cells are machines unto themselves, the focus on cell energy overlaps with the pursuit of questions ofhow energy first arose in original primordial cells, billions of years ago. Another subfield of cell biology concerns the genetics of the cell and its tight interconnection with theproteins controlling the release of genetic informationfrom the nucleus to the cell cytoplasm. Yet another subfield focuses on the structure of cell components, known assubcellular compartments. Cutting across many biological disciplines is the additional subfield of cell biology, concerned withcell communicationand signaling, concentrating on the messages that cells give to and receive from other cells and themselves. And finally, there is the subfield primarily concerned with thecell cycle, the rotation of phases beginning and ending with cell division and focused on different periods of growth and DNA replication. Many cell biologists dwell at the intersection of two or more of these subfields as our ability to analyze cells in more complex ways expands.
In line with continually increasing interdisciplinary study, the recent emergence ofsystems biologyhas affected many biological disciplines; it is a methodology that encourages the analysis of living systems within the context of other systems. In the field of cell biology, systems biology has enabled the asking and answering of more complex questions, such as the interrelationships of gene regulatory networks, evolutionary relationships between genomes, and the interactions between intracellular signaling networks. Ultimately, the broader a lens we take on our discoveries in cell biology, the more likely we can decipher the complexities of all living systems, large and small.
Biotechnology The wide concept of "biotech" or "biotechnology" encompasses a wide range of procedures for modifying living organisms according to human purposes, going back todomesticationof animals, cultivation of the plants, and "improvements" to these through breeding programs that employartificial selectionandhybridization. Modern usage also includesgenetic engineeringas well ascellandtissue culturetechnologies. TheAmerican Chemical Societydefines biotechnology as the application of biological organisms, systems, or processes by various industries to learning about the science of life and the improvement of the value of materials and organisms such as pharmaceuticals, crops, and livestock.As perEuropean Federation of Biotechnology, Biotechnology is the integration of natural science and organisms, cells, parts thereof, and molecular analogues for products and services. Biotechnology also writes on the pure biological sciences (animal cell culture,biochemistry,cell biology,embryology,genetics,microbiology, andmolecular biology). In many instances, it is also dependent on knowledge and methods from outside the sphere of biology including:
bioinformatics, a new brand of computer science
Conversely, modern biological sciences (including even concepts such as molecular ecology) are intimately entwined and heavily dependent on the methods developed through biotechnology and what is commonly thought of as the life sciences industry. Biotechnology is the research and development in the llaboratory using bioinformatics for exploration, extraction, exploitation and production from any living organisms and any source of biomass by means of biochemical engineering where high value-added products could be planned (reproduced by biosynthesis, for example), forecasted, formulated, developed, manufactured and marketed for the purpose of sustainable operations (for the return from bottomless initial investment on R & D) and gaining durable patents rights (for exclusives rights for sales, and prior to this to receive national and international approval from the results on animal experiment and human experiment, especially on the pharmaceutical branch of biotechnology to prevent any undetected side-effects or safety concerns by using the products).
By contrast, bioengineering is generally thought of as a related field that more heavily emphasizes higher systems approaches (not necessarily the altering or using of biological materials directly) for interfacing with and utilizing living things. Bioengineering is the application of the principles of engineering and natural sciences to tissues, cells and molecules. This can be considered as the use of knowledge from working with and manipulating biology to achieve a result that can improve functions in plants and animals. Relatedly, biomedical engineering is an overlapping field that often draws upon and applies biotechnology (by various definitions), especially in certain sub-fields of biomedical and/or chemical engineering such as tissue engineering, biopharmaceutical engineering, and genetic engineering.
Biophysics Biophysics is an interdisciplinary science that applies the approaches and methods of physics to study biological systems. Biophysics covers all scales of biological organization, from molecular to organismic and populations. Biophysical research shares significant overlap with biochemistry, nanotechnology, bioengineering, computational and systems biology. Molecular biophysics typically addresses biological questions similar to those in biochemistry and molecular biology, but more quantitatively, seeking to find the physical underpinnings of biomolecular phenomena. Scientists in this field conduct research concerned with understanding the interactions between the various systems of a cell, including the interactions between DNA, RNA and protein biosynthesis, as well as how these interactions are regulated. A great variety of techniques are used to answer these questions.
Fluorescent imaging techniques, as well as electron microscopy, x-ray crystallography, NMR spectroscopy, atomic force microscopy (AFM) and small-angle scattering (SAS) both with X-rays and neutrons (SAXS/SANS) are often used to visualize structures of biological significance. Protein dynamics can be observed by neutron spectroscopy. Conformational change in structure can be measured using techniques such as dual polarization interferometry, circular dichroism,SAXS and SANS. Direct manipulation of molecules using optical tweezers or AFM, can also be used to monitor biological events where forces and distances are at the nanoscale. Molecular biophysicists often consider complex biological events as systems of interacting entities which can be understood e.g. through statistical mechanics, thermodynamics and chemical kinetics. By drawing knowledge and experimental techniques from a wide variety of disciplines, biophysicists are often able to directly observe, model or even manipulate the structures and interactions of individual molecules or complexes of molecules.
In addition to traditional (i.e. molecular and cellular) biophysical topics like structural biology or enzyme kinetics, modern biophysics encompasses an extraordinarily broad range of research, from bioelectronics to quantum biology involving both experimental and theoretical tools. It is becoming increasingly common for biophysicists to apply the models and experimental techniques derived from physics, as well as mathematics and statistics (see biomathematics), to larger systems such as tissues, organs, populations and ecosystems. Biophysical models are used extensively in the study of electrical conduction in single neurons, as well as neural circuit analysis in both tissue and whole brain.
Terms And Explanations Regulation - the ability of an organism to respond to a change in its surroundings
Ingestion - take in food
Digestion - break down and absorb nutrients from food
Egestion - removal of indigestible material
Reproduction - the production of new offspring that are similar to the parents
Synthesis- a chemical reaction that combine small molecules into larger molecules
Transport - the absorption of materials into the organism and distributed throughout the organism (oxygen comes in, carbon dioxide goes out of a cell)
Respiration - cellular release of chemical energy from food
Aerobic - requires oxygen
Anaerobic - doesn't require oxygen
Excretion - the removal of waste products from chemical reactions
Cells - the basic unit of structure in an organism
Unicellular - single celled
Multicellular - many cells
Growth - the process of becoming larger
Development - the process of change during the life span to produce a more complex organism
Stimulus - a change in an organisms surroundings that causes a reaction
Response - the way an organism reacts to a stimulus
7. Texts in the natural sciences in english for high school listening
What Is an Element?
An element is a pure substance that cannot be broken down by chemical methods into simpler components. For example, the element gold cannot be broken down into anything other than gold. If you kept hitting gold with a hammer, the pieces would get smaller, but each piece will always be gold.
You can think of each kind of element having its own unique fingerprint making it different than other elements. Elements consist of only one type of atom. An atom is the smallest particle of an element that still has the same properties of that element. All atoms of a specific element have exactly the same chemical makeup, size, and mass.
There are a total of 118 elements, with the most abundant elements on Earth being helium and hydrogen. Many elements occur naturally on Earth; however, some are created in a laboratory by scientists by nuclear processes.
Instead of writing the whole elemental name, elements are often written as a symbol. For example, O is the symbol for oxygen, C is the symbol for carbon, and H is the symbol for hydrogen. Not all elements have just one letter as the symbol, but have two letters - like Al is the symbol for aluminum and Ni is the symbol for nickel. The first letter is always capitalized, but the second letter is not. Symbol names do not always match the letters in the elemental name. For example, Fe is the symbol for iron and Au is the symbol for gold. These symbol names are derived from the Latin names for those elements.
Natural resources are available to sustain the very complex interaction between living things and non-living things. Humans also benefit immensely from this interaction. All over the world, people consume resources directly or indirectly. Developed countries consume resources more than under-developed countries.
The world economy uses around 60 billion tonnes of resources each year to produce the goods and services which we all consume. On the average, a person in Europe consumes about 36kg of resources per day; a person in North America consumes about 90kg per day, a person in Asia consumes about 14kg and a person in Africa consumes about 10kg of resources per day.
In what form do people consume natural resources? The three major forms include Food and drink, Housing and infrastructure, and Mobility. These three make up more than 60% of resource use.
International and local trade has its roots in the fact that resources are not evenly distributed on the earth’s surface. Regions with crude oil can drill oil and sell to regions without oil, and also buy resources such as timber and precious metals (gold, diamonds and silver) from other regions that have them in abundance.
The uneven distribution is also the root of power and greed in many regions. Some countries use their wealth in resources to control and manipulate regions with fewer resources. Some countries and regions have even gone to war over the management, ownership, allocation, use and protection of natural resources and related ecosystems.
Natural Resources A. Overpopulation
This is probably the most significant, single threat that natural resources face. The world’s population is increasing at a very fast rate. In the USA, a baby is born every 8 seconds, and a person dies every 13 seconds. The increase in populations mean there will be pressure on almost all natural resources. How?
Land Use: With more mouths to feed and people to house, more land will need to be cultivated and developed for housing. More farming chemicals will be applied to increase food production. Many forest or vegetative lands will be converted to settlements for people, roads and farms. These have serious repercussions on natural resources.
Forests: Demand for wood (timber), food, roads and forest products will be more. People will therefore use more forest resources than they can naturally recover.
Fishing: Fresh water and sea food will face problems too as we will continue to depend heavily on them. Bigger fishing companies are going deeper into sea to catch fish in even larger quantities. Some of the fishing methods they use are not sustainable, thereby destroying much more fish and sea creatures in the process.
Need for more: Human's demand for a comfortable life means more items (communication, transport, education, entertainment and recreation) will need to be produced. This means more industrial processes and more need for raw materials and natural resources.
B. Climate Change
The alteration in climate patterns as a result of excessive anthropogenic is hurting biodiversity and many other a biotic natural resources. Species that have acclimatized to their environments may perish and others will have to move to more favorable conditions to survive.
C. Environmental Pollution
Land, water and air pollution directly affect the health of the environments in which they occur. Pollution affects the chemical make-up of soils, rocks, lands, ocean water, freshwater and underground water, and other natural phenomena. This often has catastrophic consequences.
Resource Recovery In recent years, waste has been viewed as a potential resource and not something that must end up in the landfill. From paper, plastics, wood, metals and even wastewater, experts believe that each component of waste can be tapped and turned into something very useful.
Fossil fuel use by the pulp and paper industry in the United States of America declined by more than 50% between 1972 and 2002, largely through energy efficiency measures, power recovery through co-generation and increased use of biomass.
Resource recovery is the separation of certain materials from the waste we produce, with the aim of using them again or turning them into new raw materials for use again.
It involves composting and recycling of materials that are heading to the landfill. Here is an example: Wet organic waste such as food and agricultural waste is considered waste after food consumption or after an agricultural activity. Traditionally, we collect them and send them to a landfill. In Resource Recovery, we collect and divert to composting or anaerobic digestion to produce biomethane. We can also recover nutrients through regulator-approved use of residuals.
Conservation of Natural Resources To have an environmentally sustainable secure future where we can still enjoy natural resources, we urgently need to transform the way we use resources, by completely changing the way we produce and consume goods and services.
The case of high resource consumption occurs primarily in the bigger cities of the world.
Cities worldwide are responsible for 60-80% of global energy consumption and 75% of carbon emissions, consuming more than 75% of the world’s natural resources.
To turn this unfortunate way of life around, we all have to play a role.
Education and Public Awareness
All stakeholders must aim to provide information and raise public awareness about the wonderful natural resources we have and the need to ensure its health. Even though there is a lot of information in the public domain, campaigners must try to use less scientific terms, and avoid complex terminology to send the message across. Once people understand how useful our natural resources are, they will be better placed to preserve it.
Individuals, organizations and nations
People and organizations in developed nations with high resource consumption rates must be aware of the issues of natural resources. People should understand that it is OK to enjoy all the items and gadgets at home, but also, give back to the environment by way of reducing waste, recycling waste and becoming a part of the solution. We can achieve this in our homes and workplaces by reducing waste and also by recycling the waste we create.
Governments and Policy
Governments must enforce policies that protect the environment. They must ensure that businesses and industries play fair and are accountable to all people. Incentives must be given to businesses that use recycled raw materials and hefty fines to those that still tap from raw natural resources. Businesses must return a portion of their profits to activities that aim at restoring what they have taken out of the environment.
Natural resource is anything that people can use which comes from nature. People do not make natural resources, but gather them from the earth. Examples of natural resources are air, water, wood, oil, wind energy, iron, and coal. Refined oil and hydro-electric energy are not natural resources because people make them.
We often say there are two sorts of natural resources: renewable resources and non-renewable resources.
- A renewable resource is one which can be used again and again. For example, soil, sunlight and water are renewable resources. However, in some circumstances, even water is not renewable easily. Wood is a renewable resource, but it takes time to renew and in some places people use the land for something else. Soil, if it blows away, is not easy to renew.
- A non-renewable resource is a resource that does not grow and come back, or a resource that would take a very long time to come back. For example, coal is a non-renewable resource. When we use coal, there is less coal afterward. One day, there will be no more of it to make goods. The non-renewable resource can be used directly (for example, burning oil to cook), or we can find a renewable resource to use (for example, using wind energy to make electricity to cook).
Most natural resources are limited. This means they will eventually run out. A perpetual resource has a never-ending supply. Some examples of perpetual resources include solar energy, tidal energy, and wind energy.
Some of the things influencing supply of resources include whether it is able to be recycled, and the availability of suitable substitutes for the material. Non-renewable resources cannot be recycled. For example, oil, minerals, and other non-renewable resources cannot be recycled.
All places have their own natural resources. When people do not have a certain resource they need, they can either replace it with another resource, or trade with another country to get the resource. People have sometimes fought to have them (for example, spices, water, arable land, gold, or petroleum).
When people do not have some natural resources, their quality of life can get lower. So, we need to protect our resources from pollution. For example, when they can not get clean water, people may become ill; if there is not enough wood, trees will be cut and the forest will disappear over time (deforestation); if there are not enough fish in a sea, people can die of starvation. Renewable resources include crops, wind, hydroelectric power, fish, and sunlight. Many people carefully save their natural resources so others can use them in future.
As energy is the main ‘fuel’ for social and economic development, and since energy-related activities have significant environmental impacts, it is important for decision-makers to have access to reliable and accurate data in a user-friendly format. The World Energy Council has for decades been a pioneer in the field of energy resources and every three years publishes its World Energy Resources report (WER), which is released during the World Energy Congress.
The energy sector has long lead times and therefore any long-term strategy should be based on sound information and data. Detailed resource data, selected cost data and a technology overview in the main WER report provide an excellent foundation for assessing different energy options based on factual information supplied by the WEC members from all over the world.
The work is divided into twelve resource-specific work groups, called Knowledge Networks; complemented by a further three groups investigating the cross-cutting issues of, carbon capture and storage, energy efficiency and energy storage. These Knowledge Networks provide updated data for the website and publications, as well as working on timely deep-dives with a resource focus.
An example of a magnetic force is the pull that attracts metals to the magnet. Now, the electrical field induced causes waves, called electromagnetic waves, and they can travel through a vacuum (air), particles or solids. These waves resemble the ripple (mechanical) waves you see when you drop a rock into a swimming pool, but with electromagnetic waves, you do not see them, but you often can see the effect of it. The energy in the electromagnetic waves is what we call radiant energy. There are different kinds of electromagnetic waves and all of them have different wavelengths, properties, frequencies and power, and all interact with matter differently. The entire wave system from the lowest frequency to the highest frequency is known as the electromagnetic spectrum. The shorter the wavelength, the higher its frequency and vice versa. White light, for example, is a form of radiant energy, and its frequency forms a tiny bit of the entire electromagnetic spectrum.
A population comprises all the individuals of a given species in a specific area or region at a certain time. Its significance is more than that of a number of individuals because not all individuals are identical. Populations contain genetic variation within themselves and between other populations. Even fundamental genetic characteristics such as hair color or size may differ slightly from individual to individual. More importantly, not all members of the population are equal in their ability to survive and reproduce.
Community refers to all the populations in a specific area or region at a certain time. Its structure involves many types of interactions among species. Some of these involve the acquisition and use of food, space, or other environmental resources. Others involve nutrient cycling through all members of the community and mutual regulation of population sizes. In all of these cases, the structured interactions of populations lead to situations in which individuals are thrown into life or death struggles.
In general, ecologists believe that a community that has a high diversity is more complex and stable than a community that has a low diversity. This theory is founded on the observation that the food webs of communities of high diversity are more interconnected. Greater interconnectivity causes these systems to be more resilient to disturbance. If a species is removed, those species that relied on it for food have the option to switch to many other species that occupy a similar role in that ecosystem. In a low diversity ecosystem, possible substitutes for food may be non-existent or limited in abundance.
Ecosystems are dynamic entities composed of the biological community and the abiotic environment. An ecosystem's abiotic and biotic composition and structure is determined by the state of a number of interrelated environmental factors. Changes in any of these factors (for example: nutrient availability, temperature, light intensity, grazing intensity, and species population density) will result in dynamic changes to the nature of these systems. For example, a fire in the temperate deciduous forest completely changes the structure of that system. There are no longer any large trees, most of the mosses, herbs, and shrubs that occupy the forest floor are gone, and the nutrients that were stored in the biomass are quickly released into the soil, atmosphere and hydrologic system. After a short time of recovery, the community that was once large mature trees now becomes a community of grasses, herbaceous species, and tree seedlings.
An ecosystem includes all of the living things (plants, animals and organisms) in a given area, interacting with each other, and also with their non-living environments (weather, earth, sun, soil, climate, atmosphere). In an ecosystem, each organism has its' own niche or role to play.
Consider a small puddle at the back of your home. In it, you may find all sorts of living things, from microorganisms to insects and plants. These may depend on non-living things like water, sunlight, turbulence in the puddle, temperature, atmospheric pressure and even nutrients in the water for life. (Click here to see the five basic needs of living things) This very complex, wonderful interaction of living things and their environment, has been the foundations of energy flow and recycle of carbon and nitrogen.
Anytime a ‘stranger’ (living thing(s) or external factor such as rise in temperature) is introduced to an ecosystem, it can be disastrous to that ecosystem. This is because the new organism (or factor) can distort the natural balance of the interaction and potentially harm or destroy the ecosystem. Click to read on ecosystem threats (opens in new page).
Usually, biotic members of an ecosystem, together with their abiotic factors depend on each other. This means the absence of one member or one abiotic factor can affect all parties of the ecosystem.
Unfortunately, ecosystems have been disrupted, and even destroyed by natural disasters such as fires, floods, storms and volcanic eruptions. Human activities have also contributed to the disturbance of many ecosystems and biomes. Scales of Ecosystems
Ecosystems come in indefinite sizes. It can exist in a small area such as underneath a rock, a decaying tree trunk, or a pond in your village, or it can exist in large forms such as an entire rain forest. Technically, the Earth can be called a huge ecosystem.
What is energy? Look around you. Is anything moving?
Can you hear, see or feel anything? Sure... this is because something is making something happen, and most probably, there is some power at work. This power or ability to make things happen is what we can call energy. It makes things happen. It makes change possible.
Look at the sketch below to see an example of things working, moving, or happening... with energy.
Energy in action
Energy moves cars along the roads and makes aeroplanes fly. It plays our music on the radio, heats our rooms and lights our homes. Energy is needed for our bodies, together with plants to grow and move about.
Scientists define ENERGY as the ability to do work.
Energy can be neither created nor destroyed.
Energy can be (is) stored or transferred from place to place, or object to object in different ways. There are various kinds of energy.
Let's start by looking at kinetic energy.
All moving things have kinetic energy. It is energy possessed by an object due to its motion or movement. These include very large things, like planets, and very small ones, like atoms. The heavier a thing is, and the faster it moves, the more kinetic energy it has.
Now let's see this illustration below.
There is a small and large ball resting on a table.
Kinetic energy example
Let us say both balls will fall into the bucket of water.
What is going to happen?
Motion energy example
You will notice that the smaller ball makes a little splash as it falls into the bucket. The heavier ball makes a very big splash. Why?
Note the following:
1. Both balls had potential energy as they rested on the table.
2. By resting up on a high table, they also had gravitational energy.
3. By moving and falling off the table (movement), potential and gravitational energy changed to Kinetic Energy. Can you guess which of the balls had more kinetic energy? (The big and heavier ball).
Mechanical Energy Mechanical energy is often confused with Kinetic and Potential Energy. We will try to make it very easy to understand and know the difference. Before that, we need to understand the word ‘Work’.
‘Work’ is done when a force acts on an object to cause it to move, change shape, displace, or do something physical. For, example, if I push a door open for my pet dog to walk in, work is done on the door (by causing it to open). But what kind of force caused the door to open? Here is where Mechanical Energy comes in.
Mechanical energy is the sum of kinetic and potential energy in an object that is used to do work. In other words, it is energy in an object due to its motion or position, or both. In the 'open door' example above, I possess potential chemical energy (energy stored in me), and by lifting my hands to push the door, my action also had kinetic energy (energy in the motion of my hands). By pushing the door, my potential and kinetic energy was transferred into mechanical energy, which caused work to be done (door opened). Here, the door gained mechanical energy, which caused the door to be displaced temporarily. Note that for work to be done, an object has to supply a force for another object to be displaced.
Here is another example of a boy with an iron hammer and nail.
The iron hammer on its own has no kinetic energy, but it has some potential energy (because of its weight).
To drive a nail into the piece of wood (which is work), he has to lift the iron hammer up, (this increases its potential energy because if its high position).
And force it to move at great speed downwards (now has kinetic energy) to hit the nail.
The sum of the potential and kinetic energy that the hammer acquired to drive in the nail is called the Mechanical energy, which resulted in the work done.
Sound Waves Sound energy is usually measured by its pressure and intensity, in special units called pascals and decibels. Sometimes, loud noise can cause pain to people. This is called the threshold of pain. This threshold is different from person to person. For example, teens can handle a lot higher sound pressure than elderly people, or people who work in factories tend to have a higher threshold pressure because they get used to loud noise in the factories.
Heat (Thermal energy)
Matter is made up of particles or molecules. These molecules move (or vibrate) constantly. A rise in the temperature of matter makes the particles vibrate faster. Thermal energy is what we call energy that comes from the temperature of matter. The hotter the substance, the more its molecules vibrate, and therefore the higher its thermal energy.
For example, a cup of hot tea has thermal energy in the form of kinetic energy from its vibrating particles. When you pour some milk into your hot tea, some of this energy is transferred from the hot tea to the particles in the cold milk. What happens next? The cup of tea is cooler because it lost thermal energy to the milk. The amount of thermal energy in an object is measured in Joules.
Temperature The temperature of an object is to do with how hot or cold it is, measured in degrees Celsius (°C). Temperature can also be measured in a Fahrenheit scale, named after the German physicist called Daniel Gabriel Fahrenheit (1686 – 1736). It is denoted by the symbol 'F'. In Fahrenheit scale, water freezes at 32 °F, and boils at 212 °F. In Celsius scale, water freezes at 0°C and boil at 100°C.
A thermometer is an instrument used to measure the temperature of an object.
Let's look at this example to see how thermal energy and temperature are related:
A swimming pool at 40°C is at a lower temperature than a cup of tea at 90°C. However, the swimming pool contains a lot more water. Therefore, the pool has more thermal energy than the cup of tea even though the tea is hotter than the water in the pool.
Let us see this example below:
If we want to boil the water in these two beakers, we must increase their temperatures to 100°C. You will notice that will take longer to boil the water in the large beaker than the water in the small beaker. This is because the large beaker contains more water and needs more heat energy to reach 100°C.
Polymers are studied in the fields of biophysics and macromolecular science, and polymer science (which includes polymer chemistry and polymer physics). Historically, products arising from the linkage of repeating units by covalent chemical bonds have been the primary focus of polymer science; emerging important areas of the science now focus on non-covalent links. Polyisoprene of latex rubber and the polystyrene of Styrofoam are examples of polymeric natural/biological and synthetic polymers, respectively. In biological contexts, essentially all biological macromolecules—i.e., proteins (polyamides), nucleic acids (polynucleotides), and polysaccharides—are purely polymeric, or are composed in large part of polymeric components—e.g., isoprenylated/lipid-modified glycoproteins, where small lipidic molecules and oligosaccharide modifications occur on the polyamide backbone of the protein.
A polymer is a large molecule, or macromolecule, composed of many repeated subunits. Because of their broad range of properties, both synthetic and natural polymers play an essential and ubiquitous role in everyday life. Polymers range from familiar synthetic plastics such as polystyrene to natural biopolymers such as DNA and proteins that are fundamental to biological structure and function. Polymers, both natural and synthetic, are created via polymerization of many small molecules, known as monomers. Their consequently large molecular mass relative to small molecule compounds produces unique physical properties, including toughness, viscoelasticity, and a tendency to form glasses and semi crystalline structures rather than crystals.
A nano-world of technologies There are high hopes that research in nanotechnology will translate into many products and devices that will help people. The technology will affect a wide range of fields, including transportation, sports, electronics, and medicine. Some of the current and future possibilities of nanotechnology includes:
- Medicine: Researchers are working to develop nanorobots to help diagnose and treat health problems. Medical nano robots, also called nanobots, could someday be injected into a person bloodstream. In theory, the nanobots would find and destroy harmful substances, deliver medicines, and repair damage.
- Sports: Nanotechnology has been incorporated in outdoor fabrics to add insulation from the cold without adding bulk. In sports equipment, nanotech metals in golf clubs make the clubs stronger yet lighter, allowing for greater speed. Tennis balls coated with nanoparticles protect the ball from air, allowing it to bounce far longer than the typical tennis ball.
- Materials Science: Nanotechnology has led to coatings that make fabric stain proof and paper water resistant. A car bumper developed with nanotechnology is lighter yet a lot harder to dent than conventional bumpers. And nanoparticles added to surfaces and paints could someday make them resistant to bacteria or prevent dirt from sticking.
Electronics: The field of nano-electronics is working on miniaturizing and increasing the power of computer parts. If researchers could build wires or computer processing chips out of molecules, it could dramatically shrink the size of many electronics.
Heal The World
Biotech is helping to heal the world by harnessing nature's own toolbox and using our own genetic makeup to heal and guide lines of research by:
Reducing rates of infectious disease;
Saving millions of children's lives;
Changing the odds of serious, life-threatening conditions affecting millions around the world;
Tailoring treatments to individuals to minimize health risks and side effects;
Creating more precise tools for disease detection; and
Combating serious illnesses and everyday threats confronting the developing world.
Fuel The World
Biotech uses biological processes such as fermentation and harnesses biocatalysts such as enzymes, yeast, and other microbes to become microscopic manufacturing plants. Biotech is helping to fuel the world by:
Streamlining the steps in chemical manufacturing processes by 80% or more;
Lowering the temperature for cleaning clothes and potentially saving $4.1 billion annually;
Improving manufacturing process efficiency to save 50% or more on operating costs;
Reducing use of and reliance on petrochemicals;
Using biofuels to cut greenhouse gas emissions by 52% or more;
Decreasing water usage and waste generation; and
Tapping into the full potential of traditional biomass waste products.
Feed The World
Biotech improves crop insect resistance, enhances crop herbicide tolerance and facilitates the use of more environmentally sustainable farming practices. Biotechis helping to feed the world by:
Generating higher crop yields with fewer inputs;
Lowering volumes of agricultural chemicals required by crops-limiting the run-off of these products into the environment;
Using biotech crops that need fewer applications of pesticides and that allow farmers to reduce tilling farmland;
Developing crops with enhanced nutrition profiles that solve vitamin and nutrient deficiencies;
Producing foods free of allergens and toxins such as mycotoxin; and
Improving food and crop oil content to help improve cardiovascular health.
Have you ever heard the expression “you can’t tell the players without a program” and found it to be true? Sometimes you need background information, a list of the players, their titles or functions, definitions, explanations of interactions and rules to be able to understand a sporting event, a theatrical play or a game. The same is true for understanding the subtle but important differences among the various components that make up an ecosystem.
Terms suchas individual, population, species, community andecosystem all represent distinct ecological levels and are not synonymous, interchangeable terms. Here is your brief guide or program to understanding these ecological players.
You are an individual, your pet cat is an individual, a moose in Canada is an individual, a coconut palm tree on an island in the Indian Ocean is an individual, a gray whale cruising in the Pacific Ocean is an individual, and a tapeworm living in the gut of a cow is an individual, as is the cow itself. An individual is one organism and is also one type of organism (e.g., human, cat, moose, palm tree, gray whale, bacterium, or cow in our example). The type of organism is referred to as the species. There are many different definitions of the word species, but for now we’ll leave it simply that it is a unique type of organism. As a grammatical aside, note that the word “species” always ends in an “s”. Even if you are referring to just one type of organism, one species, it is a species; there is no such thing as specie. That’s just one of those grammatical facts of life.
So what is a gene? Genes are instruction manuals in our body. They are molecules in our body that explain the information hidden in our DNA, and supervises our bodies to grow in line with that information.
It is believed that each cell in our body contains over 25,000 genes, all working together. These genes carry specific biological codes or information that determine what we inherit from our parents.
Genes are also a small section of Deoxyribonucleic Acid (DNA), a chemical that has a genetic code for making proteins for living cells. Proteins are the building blocks for living things. Almost everything in our body, bones, blood and muscles are all made up of proteins, and it is the job of the genes to supervise protein production.
Genes are not things we see with our bare eyes. They can only be seen with powerful microscopes, and they are thread-like in nature, found in our chromosomes.
Altered or mutated genes:
Sometimes our genes do not work well. Sometimes we inherit genes that have some problems. Such genes (also called mutated or altered genes) do not perform their functions well, and cause defects in our organs. Some inherited diseases like cancer and sickle cell have been linked to such mutated or bad genes. There is still a lot of research going on in the study of genes to learn more about them.
What is a chromosomes? A chromosome is just a compact store of DNA. A chromosome is simply a lot of DNA strands folded and compacted together. This compacting is done in a special way. The Chemical bases in the DNA are held in place by The Double Helix. The Double Helix continues to wrap itself around proteins. They continue to wrap around several protein molecules and into an even bigger compact set which we call Chromosome.
Chromosomes are all contained in the nucleus of the cell. nucleus
The number of Chromosomes in a cell depends on what cell it is. Chromosomes in a tiny goldfish may be a lot less than that of a human. In fact, humans have 46 chromosomes in each of the cells of our organs. These are organized into two sets of 23 chromosomes.
Each human gets 23 chromosomes from their mom, and 23 chromosomes from their dad. This is why almost everyone has some traits they got from their parents.
By looking at the chromosomes in the cell, we can tell the gender of an unborn baby. Males have XY chromosomes and females have XX chromosomes.
These are called Sex Chromosomes.
During sexual activity (mating), the male releases the sperm cell and the female releases the ova (female cell). Remember we said previously that the human body has 23 pairs of chromosomes? Yes, the 23rd chromosome is your sex chromosomes. Boys carry XY chromosomes and girls carry XX cromosomes.sex chromosomes During fertilization, each parent contributes a cell each. The female always contributes and X cell (because that all she has, XX chromosome) The male contributes either an X or a Y cell. The male has no control over this, as it is purely random.
If the male releases and X chromosome, it adds to the X chromosome of the female, it forms an XX— and the gender of the baby will be a girl. If the male releases a Y chromosome and adds to the females X chromosome, it forms an XY and the gender of the baby is a boy.
In recent years, it is possible to have IVF which means In vitro fertilization. This is where the female and male cells are taken from the parents and fertilized in a lab. In IVF, it is possible to choose which sex chromosomes to fertilize. This means you can choose to have a boy or girl.
What is genetic variation? Individuals in a population are not exactly the same.
Each individual has its unique set of traits, such as size, color, height, body weight, skin colour and even the ability to find food.
Sometimes, offspring’s of the same parents still differ a lot among themselves. You can find that among 3 sisters, one may be very tall, the other may have dark hair and the third may have a rounded nose tip. Such differences in individuals from the same parents are called variation.
Characteristics or traits that are inherited are determined by genetic information. Some other traits like dialect or accent, scars, skin texture or even body weight may be determined by some external or environmental factors.
These factors include
Sometimes a person may not have inherited a trait, but some conditions have modified the individual to exhibits specific traits. If a child with brown eyes acquires a disease that affects his eyes and turns them yellow, that may be a diseased induced variation.
In the same vain, a child my have the tendency to be tall, but diseases and poor diet during his early years my cause him to have stunted growth.
Laser surgery is also growing in popularity and application. As its name suggests, surgeons utilize a laser to perform various procedures, including during laparoscopic procedures. For example, lasers currently are used to excise cancerous tissue from the larynx, reshape the cornea of an eye to allow a patient to see better, and even to resurface the skin of a patient's face by burning off old layers skin so that new skin can grow. The growing popularity of lasers as surgical devices is due mainly to their ability to precisely destroy unwanted or abnormal tissue without bleeding.
Another well known example of advancing surgical techniques involves combating cardiovascular disease. Because of lifestyle habits or genetic predisposition, fatty acids (plaque) sometimes build up in arterial walls. As more plaque builds up, less blood is able to flow through the artery to the heart. Ultimately, the plaque buildup may completely block the artery, preventing any blood from flowing through it. The result is cardiac arrest, which can be fatal. Surgeons have developed a technique known as angioplasty to combat the onset of cardiovascular disease. Using a technique similar to laparoscopy, a surgeon inserts a thin tube into the patient, working it up the artery to where the blockage resides. At the end of the tube is a small, balloon-like device that inflates, pressing the plaque against the arterial walls so that blood flow through the artery can be increased.
Surgeons have also developed another, more popular, procedure for dealing with coronary artery disease: the coronary bypass graft operation. By taking a portion of an artery from elsewhere in the patient's body--usually the internal mammary artery from inside the chest cavity--the new artery is grafted around the blockage of the old artery to allow blood to flow around the blockage via the new arterial route. Despite the fact that this procedure requires open-heart surgery.
Man's influence on nature. Man is not only a dweller in nature, he also transforms it. From the very beginning of his existence, and with increasing intensity human society has adapted environing nature and made all kinds of incursions into it. An enormous amount of human labour has been spent on transforming nature. Humanity converts nature's wealth into the means of the cultural, historical life of society. Man has subdued and disciplined electricity and compelled it to serve the interests of society. Not only has man transferred various species of plants and animals to different climatic conditions; he has also changed the shape and climate of his habitation and transformed plants and animals. If we were to strip the geographical environment of the properties created by the labour of many generations, contemporary society would be unable to exist in such primeval conditions.
Man and nature interact dialectically in such a way that, as society develops, man tends to become less dependent on nature directly, while indirectly his dependence grows. This is understandable. While he is getting to know more and more about nature, and on this basis transforming it, man's power over nature progressively increases, but in the same process, man comes into more and more extensive and profound contact with nature, bringing into the sphere of his activity growing quantities of matter, energy and information.
On the plane of the historical development of man-nature relations we may define certain stages. The first is that of the complete dependence of man on nature. Our distant ancestors floundered amid the immensity of natural formations and lived in fear of nature's menacing and destructive forces. Very often they were unable to obtain the merest necessities of subsistence. However, despite their imperfect tools, they worked together stubbornly, collectively, and were able to attain results. This process of struggle between man and the elements was contradictory and frequently ended in tragedy. Nature also changed its face through interaction with man. Forests were destroyed and the area of arable land increased. Nature with its elemental forces was regarded as something hostile to man. The forest, for example, was something wild and menacing and people tried to force it to retreat. This was all done in the name of civilization, which meant the places where man had made his home, where the earth was cultivated, where the forest had been cut down. But as time goes on the interaction between man and nature is characterized by accelerated subjugation of nature, the taming of its elemental forces . The subjugating power of the implements of labour begins to approach that of natural forces. Mankind becomes increasingly concerned with the question of where and how to obtain irreplaceable natural resources for the needs of production. Science and man's practical transforming activity have made humanity aware of the enormous geological role played by the industrial transformation of earth.
At present the interaction between man and nature is determined by the fact that in addition to the two factors of change in the biosphere that have been operating for millions of years—the biogenetic and the a biogenetic—there has been added yet another factor which is acquiring decisive significance—the techno genetic. As a result, the previous dynamic balance between man and nature and between nature and society as a whole has shown ominous signs of breaking down. The problem of the so-called replaceable resources of the biosphere has become particularly acute. It is getting more and more difficult to satisfy the needs of human beings and society even for such a substance, for example, as fresh water. The problem of eliminating industrial waste is also becoming increasingly complex. The threat of a global ecological crisis hangs over humanity like the sword of Damocles. His keen awareness of this fact has led man to pose the question of switching from the irresponsible destructive and polluting subjugation of nature to a reasonable harmonious interaction in the "technology-man-biosphere" system. Whereas nature once frightened us and made us tremble with her mysterious vastness and the uncontrollable energy of its elemental forces, it now frightens us with its limitations and a new-found fragility, the delicacy of its plastic mechanisms. We are faced quite uncompromisingly with the problem of how to stop, or at least moderate, the destructive effect of technology on nature. In socialist societies the problem is being solved on a planned basis, but under capitalism spontaneous forces still operate that despoils nature's riches.
Unforeseen paradoxes have arisen in the man-nature relationship. One of them is the paradox of saturation. For millions of years the results of man's influence on nature were relatively insignificant. The biosphere loyally served man as a source of the means of subsistence and a reservoir for the products of his life activity. The contradiction between these vital principles was eliminated by the fact that the relatively modest scale of human productive activity allowed nature to assimilate the waste from labour processes. But as time went on, the growing volume of waste and its increasingly harmful properties destroyed this balance. The human feedback into nature became increasingly disharmonised. Human activity at various times has involved a good deal of irrational behaviour. Labour, which started as a specifically human means of rational survival in the environment, now damages the biosphere on an increasing scale and on the boomerang principle—affecting man himself, his bodily and mental organisation. Under the influence of uncoordinated production processes affecting the biosphere, the chemical properties of water, air, the soil, flora and fauna have acquired a negative shift. Experts maintain that 60 per cent of the pollution in the atmosphere, and the most toxic, comes from motor transport, 20 per cent from power stations, and 20 per cent from other types of industry.