Biology/Citable Version: Difference between revisions
imported>Nancy Sculerati MD |
imported>Nancy Sculerati MD |
||
Line 60: | Line 60: | ||
RNA | RNA | ||
With DNA chemistry, biologists took off their parkas and came out of the refrigerated cold rooms that were the only workplaces in which RNA remained stable long enough to perform experiments with it that had elucidated the general functions of the endoplasmic reticulum and xxxx. The technique of PCR allowed automated experiments on tiny samples of DNA in a standard laboratory setting, and progress in molecular biology accelerated. | With DNA chemistry, biologists took off their parkas and came out of the refrigerated cold rooms that were the only workplaces in which RNA remained stable long enough to perform experiments with it that had elucidated the general functions of the endoplasmic reticulum and xxxx. The technique of PCR allowed automated experiments on tiny samples of DNA in a standard laboratory setting, and progress in molecular biology accelerated tremendously. | ||
Using molecular biology techniques to study the organelles that had been discovered through electron microscopy led to startlng new concepts. The mitochondria seen in active human cells were not human at all, at least not in origin. These organelles had been assimilated into eukaryotic cells and divided along with them, but according to their'' own'' genetic code, a circular strand of DNA that resembles the genome of bacteria. These energy producing organelles of animal cells were not the only organelles found that derived from a different life form. The [[chloroplast]] of plant cells | Using molecular biology techniques to study the organelles that had been discovered through electron microscopy led to startlng new concepts. The mitochondria seen in active human cells were not human at all, at least not in origin. These organelles had been assimilated into eukaryotic cells and divided along with them, but according to their'' own'' genetic code, a circular strand of DNA that resembles the genome of bacteria. These energy producing organelles of animal cells were not the only organelles found that derived from a different life form. The [[chloroplast]] of plant cells |
Revision as of 10:59, 22 November 2006
The word "Biology" is formed by combining the Greek βίος (bios), meaning 'life', and λόγος (logos), meaning 'study of'. "Biology" in its modern use was probably introduced independently by both Gottfried Reinhold Treviranus (Biologie oder Philosophie der lebenden Natur, 1802) and by Jean-Baptiste Lamarck (Hydrogéologie, 1802). Although the word "biology" is sometimes said to have been coined in 1800 by Karl Friedrich Burdach, it appears in the title of Volume 3 of Michael Christoph Hanov's Philosophiae naturalis sive physicae dogmaticae: Geologia, biologia, phytologia generalis et dendrologia, published in 1766.
Biology is the science of life. Biologists study all aspects of living things, including each of the many life forms on earth. Most current research in biology describes the dynamic processes that enable life, rather than individual types of plants, animals or micro-organisms. Those vital processes include the harnessing of energy, the synthesis of the materials that make up the body, the healing of injuries, and the reproduction of the entire organism, among many other activities.
Living organisms have been of interest to all peoples throughout history, and, accordingly, the roots of biology go back to earliest mankind. Curiosity about the physical beings of people, plants, and animals still runs deep in every human society. How is it that these bodies change; develop, grow, and age? What is it that underlies the divide between inanimate objects and the living entities in the world? Some of those questions stem from our desire to control life processes, and to exploit natural resources. Pursuit of the answers has led to an understanding of organisms that has steadily improved our standard of living through the ages. But questions also come from a desire to understand nature rather than to control it, and the very core of that desire is sparked by a commonly felt need to understand the human condition and the nature of the world. Biology brings its own set of answers to these questions, and provides a useful way of learning about living things.
Not all natural lore is biology, no matter how accurate or helpful, and no matter that the subject is a plant or animal. Biologists incorporate an understanding of mathematics, physics, chemistry and other sciences, along with adherence to the scientific method, to their study of living things. Still, all human interaction with nature eventually adds to the biologists' understanding, whether the original ideas came from evidence in the laboratory or the studbook of the horseman, from the notebook of the ecologist or the field notes of the hunter.
The Scope of Biology
How did life begin? What features separate something that is alive from something that is not alive?. The biologist uses science to try to answer these fundamental questions, questions that also concern the philosopher, the rabbi, the iman, and the priest - as well as every person who retains a sense of wonder. Whether scientific thinking about these issues is compatable with religious beliefs is itself contentious. Some great thinkers, such as the physicist Albert Einstein, have found no real conflict between the varying teachings of science and religion, but consider Divinity and the Natural Universe to be one and the same (see Albert Einstein for detailed discussion with references). In this view, the differences between mathematical equations and the language of prophets are simply two different forms of human expression, each attempting to describe a higher dimension than ordinary human experience.
Biology is also used to answer very practical questions, posed to advance medical and dental care, agriculture and animal husbandry.
Many independent scientific fields make up Biology, but all are related. Natural History (the study of individual species like white-tailed deer, sugar maple trees, box jellyfish and timber wolves) was one of the first areas of biology to develop. In natural history, whole organisms are studied in an attempt to make sense of the order of Nature. When the natural histories of plants and animals are considered in a context of how each affects the other and their environment, then the biologist's focus is on ecology. Some fields of biology focus on the natural history of living organisms and their interactions within a certain realm of the earth, as in marine biology; others focus on particular aspects of the bodies of living organisms, like their structure (Anatomy) or function (Physiology). Studies of animals form the field of Zoology, whereas the study of plants is called Botany. Medicine and the Health Sciences apply biology to understanding disease and to improving health. Many of the academic disciplines that make up biology are listed at the bottom of this article along with a brief description. Further information about each is provided through links to other articles within Citizendium that can be accessed by clicking each discipline's name.
The development of biology
The remainder of this article explores selected themes in biology while providing a very abbreviated overview of the development of the science. For a more comprehensive review, please see:
Roots of Biology in the Ancient World
Whether foragers or farmers, hunters or herders, people have always depended on plants and animals for sustenance. Rather than take this sustenance simply as found, humans generally change their immediate environment by carrying food items from place to place, and processing them in various fashions. Because of human intelligence, xxxxx this section needs development - explain about start with sugary cob, end up planting seeds. ( Ref -Sweet Beginnings: Stalk Sugar and the Domestication of Maize1/Comments/ReplyJohn Smalley, Michael Blake, Sergio J Chavez, Warren R Deboer, et al. Current Anthropology. Chicago: Dec 2003. Vol. 44, Iss. 5; p. 675). When there is intellectual consideration of what plants are; and evidence-based experiments are used to understand their growth, then botany, the science of plants, joins agriculture as a human endeavor.
The formal foundation of Anatomy and Zoology both date back at least as far as the ancient Greek philosopher Aristotle, to the Fourth Century BC. In the first known book on how life in the womb begins, Aristotle suggested that the woman provides the substance needed to build a new baby while the man provides the "soul" that gives this substance human life, its basic humanity. Aristotle used logic and observation to arrive at his theory, which, in the main, was still accepted 2000 years later. Aristotle based his explanation of the creation of a new baby on a philosophic principle called epigenesis: the emergence of order from disorder, and current biology holds that life processes xxxstatement about using energy to combat entropy. His conclusion that the woman's contribution was the mere soil for the man's seed, and that the male contribution to a new human contained the nascent child that simply required a nurturing womb to grow, was likely influenced by the general agreement, in his society, that women were not as highly developed as men. It may also have come from the examination of the seeds of some trees, in which the entire immature plant is contained within the husk, and springs into independant life as a young tree once planted. A popular idea that grew out of Aristotle's musings was that sperm actually contained a perfect miniature version of the new baby - a homunculus.
Early Biology : The Establishment of the Scientific Method
A workable classification of living things was made practical by Linneas using a form of systematic nomenclature he invented. This gives a unique name to each kind of plant and animal, and organizes all of them into a classification scheme that stresses similarities of physical features. This naming system is still used today, and each known species has one unique scientific name that biologists all over the world recognize.
Technology advances Biology
First Glimpses of the Microscopic World
The features of plants and animals have often been understood on an entirely different levels with technological advances that provided new means for examining them. For example, the microscope, modified by the hands of Antoni van Leeuwenhoek in the Seventeenth Century, revealed details of structure in the bodies of organisms that had never before been even suspected. One of the new sights he described were Individual ovum and spermatozoa, and being quite familiar with the theories of Aristotle, he reported that he could actually see homunculi in the heads of the living sperm - an example of even a great scientist sometimes seeing what he expected to see, rather than what was really there. Science is always influenced by past ideas. No scientist can consider any idea, or analyze experiemental results without using his or her mind. That mind is both consciously and unconsciously stamped with the culture that produced it.
File:Drawing of sperm by van Leeuwenhoek showing homunculus.jpg
Not only was the structure of flesh and plants seen at a new level of detail with the microscope, but completely new types of organisms were also revealed: micro-organisms that could not be detected with the naked eye. [1] And so, like all important technological advances in biology, the microsocope led to new ideas about living things. The concept that tissues were composed of cells was initiated, the field of microbiology was born, and the ground was prepared for the germ theory of disease, an idea that helped bring the traditional practice of western medicine (sometimes called allopathy) into the field of health science and modern medicine.
Further developments led to the modern compound microscope by the end of the 19th century, with much higher resolution, and eventually the late 20th century electron microscopes were built using electronic technology. Science differs from religious and political doctrine in at least one major manner – tenants are not to be held sacred but questioned and tested. This has proved damaging for many of them, including the homunculus theory of fetal development. With improved optics and the new imaging techniques of scanning and transmission electron microscopes, that "little man" inside the sperm cell vanished forever.
Ultra-high power magnification imaging creates new knowledge:Cell Biology begins
With ultra-high power examination of cells, another new discipline within biology began to flourish, and the idea that living organisms were all composed of cells clarified. Scientists in the field of cell biology began to unravel the inner architecture of cells, discovering discrete organelles that could only be seen well with tremendous magnification power. Closer visual examination of the structure of the cell was combined with the ability to physically separate out the components of the cells in bulk by weight and chemical properties and analyze each fraction using methods from biochemistry and biophysics. The important techniques that allowed this kind of analysis include ultracentrifugation and gel electrophoresis.
Understanding the ultrastructure of cells along with correlated chemical and physical properties of the organelles brought more new ideas to biology. An example of both a new organelle and, new idea -mitochondria. Cell biologists applied their findings to the systematic classification of plants and animals, and relationships were further refined.
Molecular Biology.
Double Helix
RNA
With DNA chemistry, biologists took off their parkas and came out of the refrigerated cold rooms that were the only workplaces in which RNA remained stable long enough to perform experiments with it that had elucidated the general functions of the endoplasmic reticulum and xxxx. The technique of PCR allowed automated experiments on tiny samples of DNA in a standard laboratory setting, and progress in molecular biology accelerated tremendously.
Using molecular biology techniques to study the organelles that had been discovered through electron microscopy led to startlng new concepts. The mitochondria seen in active human cells were not human at all, at least not in origin. These organelles had been assimilated into eukaryotic cells and divided along with them, but according to their own genetic code, a circular strand of DNA that resembles the genome of bacteria. These energy producing organelles of animal cells were not the only organelles found that derived from a different life form. The chloroplast of plant cells
The age-old discussion of just how a new baby came to be born of man and woman took an unexpected turn with xxxxxx as well. Apparently, the single cell that every human begins with does not receive identical contributions from mother and father, at all. One of the biggest differences between what each give their baby has to do with what’s in the egg, but not in the sperm, and that would be cell organelles, specifically these mitochondria.
Imprinting of genes by parental origin is another manner in which xxxx. Back to corn,
Main topics and discoveries
Major discoveries in biology include:
Disciplines within biology
- Anatomy: The study of structure
- Biochemistry: The chemistry of living things is a field of both biology and chemistry
- Cell Biology: The study of the components of cells
- Genetics: The study of the inheritance of characteristics, genes and DNA
- Marine Biology: The study of life in the seas and oceans
- Behavior:
- Biodiversity:
- Biogeography:
- Botany:
- Developmental biology:
- Ecology:
- Ethology:
- Evolutionary biology:
- Molecular biology:
- Physiology:
- systematics:
- Taxonomy:
- Zoology:
References
- Citations
- ↑ Anton van Leeuwenhoek. Encyclopedia of World Biography, 2nd ed. 17 Vols. Gale Research, 1998. Reproduced in Biography Resource Center. Farmington Hills, Mich.: Thomson Gale. 2006
- Further reading
Selected external links
The following links have been reviewed and are recommended because, at the time of their inclusion, they provided accurate information and portals to additional excellent web resources. Many other excellent links have been omitted through no fault of their own.
Plain and technical language
- The American Institute of Biological Sciences (ABIBS) Virtual Library is free to all visitors
- The Bio-Web reviews and gives access to information in Cell and Molecular Biology, includes "news" in plain language
- Cell and Molecular Biology Online is a resource for professionals that includes links and some information for all
- Kimball's Biology Pages represent an online biology textbook