Branches Of Biological Study
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The scope of biology is broad and therefore contains many branches and sub disciplines. Biologists may pursue one of those sub disciplines and work in a more focused field. For instance, molecular biology studies biological processes at the molecular level, including interactions among molecules such as DNA, RNA, and proteins, as well as the way they are regulated. Microbiology is the study of the structure and function of microorganisms. It is quite a broad branch itself, and depending on the subject of study, there are also microbial physiologists, ecologists, and geneticists, among others.
Another field of biological study, neurobiology, studies the biology of the nervous system, and although it is considered a branch of biology, it is also recognized as an interdisciplinary field of study known as neuroscience. Because of its interdisciplinary nature, this sub discipline studies different functions of the nervous system using molecular, cellular, developmental, medical, and computational approaches.
What Are Model Organisms
- Model organisms are non-human species that are used in the laboratory to help scientists understand biological processes.
- They are usually organisms that are easy to maintain and breed in a laboratory setting.
- For example, they may have particularly robust that are easily studied and manipulated in the lab, this is useful for scientists studying development.
- Or they may occupy a pivotal position in the evolutionary tree, this is useful for scientists studying
Levels Of Organization In Philosophical Debates
Levels of organization figure into a number of perennial debates inphilosophy of science. Here we go through three broad topics wherelevels traditionally have and continue to play a prominent role:Reduction, antireductionism and pluralism, and downward causation.Within these topics, we focus on issues and theories that directlyinvolve levels.
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Themes And Concepts Of Biology
- Describe the properties of life
All living organisms share several key characteristics or functions: order, sensitivity or response to the environment, reproduction, growth and development, regulation, homeostasis, and energy processing. When viewed together, these eight characteristics serve to define life.
How Did Cells Originate
Researchers hypothesize that all organisms on Earth today originated from a single cell that existed some 3.5 to 3.8 billion years ago. This original cell was likely little more than a sac of small organic molecules and RNA-like material that had both informational and catalytic functions. Over time, the more stable DNA molecule evolved to take over the information storage function, whereas proteins, with a greater variety of structures than nucleic acids, took over the catalytic functions.
As described in the previous section, the absence or presence of a nucleus and indeed, of all membrane-bound organelles is important enough to be a defining feature by which cells are categorized as either prokaryotes or eukaryotes. Scientists believe that the appearance of self-contained nuclei and other organelles represents a major advance in the evolution of cells. But where did these structures come from? More than one billion years ago, some cells “ate” by engulfing objects that floated in the liquid environment in which they existed. Then, according to some theories of cellular evolution, one of the early eukaryotic cells engulfed a prokaryote, and together the two cells formed a symbiotic relationship. In particular, the engulfed cell began to function as an organelle within the larger eukaryotic cell that consumed it. Both chloroplasts and mitochondria, which exist in modern eukaryotic cells and still retain their own genomes, are thought to have arisen in this manner .
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How Many Types Of Organisms Are There
An organism generally refers to a single or individual living species, which exhibits all the properties of life. These can be a plant, animal, bird, insect and even a microbe. There are billions to trillions of different types of organisms living on our planet Earth. Based on the different criteria all these organisms are classified into different groups. Every type of species of organism varies from one another.
Teleological Behavior Of Organisms
One kind of activity, which is a consequence of organization at a level higher than that of the organism’s physical parts, is directive or teleological behavior. Directiveness is an aspect of organisms that is shown in their physiology, in the behavior of individual animals, and in the social systems of some animals and an account of directiveness is not only legitimate but necessary. E. S. Russell argues that since directiveness is a fact, then a physiological process, or piece of animal behavior, cannot be understood until we understand its function or its goal.
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Browse More Topics Under The Living Organisms And Their Surroundings
Most plants have green leaves. Leaves are green because they contain a green pigment called chlorophyll. Chlorophyll gives plants the special ability to make their own food using light, water, and carbon dioxide.
Animals cannot make their own food, as they are called heterotrophs. Both animals and plants need substances, called nutrients. Plants absorb nutrients such as nitrogen, phosphorus, and calcium from the soil. These nutrients enter the bodies of animals when they eat plants or flesh of other animals.
Some organisms feed on the bodies of dead plants and animals and release the nutrients trapped inside them. Animals that feed on the dead bodies of other animals are scavengers. For example, hyena and vulture. Tiny organisms that feed on the remnants of dead plants and animals to break them down into simpler substances are . For example, bacteria and fungi. Scavengers and decomposers play important roles in the environment as:
- They keep the environment clean by removing the bodies of dead plants and animals.
- They help in the recycling of nutrients in the environment.
Characteristics Of Model Organisms
A few of the characteristics of model organisms are listed below.
Relatively short generation time .
Relatively easy to maintain and grow in a restricted space.
Relatively easy to provide necessary nutrients for growth.
Relatively well-understood development and growth.
Closely resemble other organisms or systems.
Baker’s or brewer’s yeast
Advantages Of Using Model Organisms In Genetics Research
Many model organisms have the ability to reproduce in vast numbers.
Some have an extremely short generation time, or the time between birth and the ability to reproduce, allowing multiple generations to be observed at the same time.
Mutants allow scientists to investigate certain traits or diseases. These are model organisms that have had a change or mutation in their DNA, which may have resulted in a change in a characteristic.
Some model organisms contain genes or genomes that are similar to humans.
To build highly detailed genetic maps, model organisms might be used:
Genetic maps are a visual representation of the position of distinct genes on a chromosome, similar to a real map but with major landmarks in the genome.
For example, SNPs or genes that differ amongst individuals of the same species.
What Are The Characteristics Shared By Biological Organisms
Properties of life: Order
Biological organisms are organized and coordinated structures made up of one or more cells, which are tiny structures we consider as the fundamental unit of life.
Each cell is incredibly complex: at the fundamental level, it is composed of atoms. These atoms make up molecules. These molecules come together to form complex compartmentalized cell structures called organelles.
Properties of life: Response to stimuli
Stimuli are things that can elicit a response from a living organism.
Organisms can respond by moving toward the stimulus this is called a positive response. They can also respond by moving away from the stimulus this is called a negative response. For example, plants exposed to light stimuli might respond by bending toward the light.
Properties of life: Reproduction
Organisms can replicate themselves by passing on their genetic information to their offspring. By passing on their genetic information, the offspring will belong to the same species and have similar traits.
Properties of life: Growth and development
Properties of life: Regulation
Organisms require multiple complex regulatory mechanisms to coordinate their internal processes, such as transporting nutrients and responding to stimuli.
Properties of life: Homeostasis
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Referencesisbn Links Support Nwe Through Referral Fees
- Alberts, B., et al. 2002. Molecular Biology of the Cell, 4th edition. New York, NY: Garland Science. ISBN 0815332181.
- Durrant, Michael . 1993. Aristotle’s De Anima in Focus. London: Routledge. ISBN 0415053404.
- Gill S.R., et al. 2006. Metagenomic analysis of the human distal gut microbiomeScience 312: 1355-1359. Retrieved March 27, 2020.
- Luria, S. E., S. J. Gould, and S. Singer. 1981. A View of Life. Menlo Park, CA: Benjamin/Cummings Pub. Co. ISBN 0805366482.
- Margulis L., and D. Sagan. 1986. Microcosmos. New York: Summit Books. ISBN 0671441698.
- Margulis, L., and D. Sagan. 1995. What Is Life? Simon & Schuster. ISBN 0684810875.
- Schrodinger, E. 1944/2000. What is Life?. Cambridge University Press. ISBN 0521427088
- Southwick, E. E. 1983. The honey bee cluster as a homeothermic superorganism. Comparative Biochemistry and Physiology 75A: 741â745.
- Towle, A. 1989. Modern Biology. Austin, TX: Holt, Rinehart and Winston. ISBN 0030139198
Organisms Shape The Environment
The environment is dynamic because physical processes drive change in Earth’s attributes over time. However, research demonstrates that life itself drives equally important environmental changes. Because other organisms are part of each individuals environment, changes in species distributions can profoundly alter ecological interactions within communities. In some cases, the loss of a native species, or introduction of a non-native one, can threaten the survival of other organisms. For this reason, the conservation of endangered organisms and control of invasive species are of broad concern.
Philosophical Accounts Of Levels Of Organization
A recurring motif in the literature on levels of organization is tolament the haphazard or unreflective way in which terms such ashierarchy or levels are applied, and tocall for more precise analyses . However, surprisingly fewphilosophers or scientists have taken up the challenge of developing asubstantial theory or account of levels of organization. In thissection, we discuss three major accounts put forward in philosophy ofscience to clarify or posit what exactly levels of organization are.These are Paul Oppenheim and Hilary Putnamslayer-cake account, the mechanist account developed andadvocated by Carl Craver and William Bechtel, and William Wimsatts local maximaaccount . Afterthese, we also go through recent skeptical approaches to the idea oflevels of organization.
References And Recommended Reading
Beerling,D. The Emerald Planet: How Plants ChangedEarth’s History. Oxford, UK: Oxford University Press, 2007.
Biro, P.A., Beckmann, C. et al. Small within-dayincreases in temperature affects boldness and alters personality in coral reeffish. Proceedings of the Royal Society B:Biological Sciences277, 71-77 .
Burger,W. C. Flowers: How They Changed the World.Amherst, NY: Prometheus Books, 2006.
Chapin,F. S., Matson, P. A. et al. Principles of Terrestrial Ecosystem Ecology.New York, NY: Springer Science+Business Media Inc., 2002.
Chapin,F. S., Vitousek, P. M. et al. Thenature of nutrient limitation in plant communities. The American Naturalist127,48 .
Cowen, R.History of Life. Boston, MA:Blackwell Scientific Publications, 1990.
Dethlefsen,L., Huse, S. et al. The pervasiveeffects of an antibiotic on the human gut microbiota, as revealed by deep 16SrRNA sequencing. PLoS Biology6, e280 .
Gaston, K. J. Global patterns inbiodiversity. Nature405, 220-227 .
Hata, H.,Watanabe, K. et al. Geographicvariation in the damselfish-red alga cultivation mutualism in the Indo-WestPacific. BMC Evolutionary Biology10, 185 .
Kleidon,A., Fraedrich, K. et al. A greenplanet versus a desert world: estimating the maximum effect of vegetation onthe land surface climage. Climatic Change44, 471-493 .
Marquez,L. M., Redman, R. S. et al. A virusin a fungus in a plant: three-way symbiosis required for thermal tolerance. Science315, 513-515.
May, R.M. How many species are there on Earth? Science241, 1441-1449.
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What Are The Different Categories Of Cells
Rather than grouping cells by their size or shape, scientists typically categorize them by how their genetic material is packaged. If the DNA within a cell is not separated from the cytoplasm, then that cell is a prokaryote. All known prokaryotes, such as bacteria and archaea, are single cells. In contrast, if the DNA is partitioned off in its own membrane-bound room called the nucleus, then that cell is a eukaryote. Some eukaryotes, like amoebae, are free-living, single-celled entities. Other eukaryotic cells are part of multicellular organisms. For instance, all plants and animals are made of eukaryotic cells sometimes even trillions of them .
The Multidisciplinary Nature Of Biology
Biology is often researched in conjunction with other fields of study, including mathematics, engineering and the social sciences. Here are a few examples:
Astrobiology is the study of the evolution of life in the universe, including the search for extraterrestrial life, according to NASA . This field incorporates principles of biology with astronomy.
Bioarchaeologists are biologists who incorporate archaeological techniques to study skeletal remains and derive insights about how people lived in the past, according to George Mason University .
Bioengineering is the application of engineering principles to biology and vice versa, according to the University of California Berkeley . For example, a bioengineer might develop a new medical technology that better images the inside of the body, like an improved Magnetic Resonance Imaging that scans the human body at a faster rate and higher resolution, or apply biological knowledge to create artificial organs, according to the journal Cell Transplant.
Biotechnology involves using biological systems to develop products, according to the Norwegian University of Science and Technology . For example, biotechnologists in Russia genetically engineered a better-tasting and more disease-resistant strawberry, which the researchers described in their 2007 study published in the journal Biotechnology and Sustainable Agriculture 2006 and Beyond .
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The Historical Origins Of The Concept
When levels of organization are understood as belonging to the broadercategory of hierarchical depictions of nature, their history can betraced all the way back to the early days of western science andphilosophy. Aristotle suggested that living things could be arrangedin a graded scale, starting from plants at the bottom and ending withhumans at the top. This idea was further developed in Neoplatonism,and in Medieval times, it transformed into the idea of theGreat Chain of Being . This ScalaNaturae conveyed a hierarchical conception of the world asmodeled after the perfection of the Deity: at the top, there is God,and at lower rungs, angels, humans, animals, plants, and so on. Afterthe scientific revolution, more scientific classifications of naturestarted to appear, the most famous ones being Linneaustaxonomical system and Auguste Comtes hierarchy of the sciences.
The roots of the contemporary notion of levels of organization and theassociated hierarchical thinking are best linked to the efforts oforganicist biologists of the early-mid 20th century . Particularly important to the introduction anddevelopment of the levels concept were Joseph Woodger ,Ludwig von Bertalanffy , and Joseph Needham . These individuals were in turn influenced by Alfred NorthWhiteheads philosophy .
The levels concept proved to be a linchpin of these main tenets.Joseph Woodger, combining these features, thus expresses the basicthinking behind levels of organization:
Levels In Biological Theory
Besides the more philosophical debates discussed above, levels oforganization also play an important conceptual role in biologicalresearch and theory. Interestingly, this growing body of literature onlevels in evolutionary biology is almost entirely disconnected fromthe debates on levels in philosophy of science discussed above.
A prominent example is the issue of levels of selection. In thisdebate, the hierarchical organization of nature into levels is animportant background assumption, as the aim is to find out at whichlevel of the biological hierarchy natural selection is taking place. Although Darwins originalaccount was focused on evolution at the level of organisms, arguablythe conditions for natural selection can be formulated abstractlywithout referring to any specific kinds of entities, which allows fornatural selection to operate at any level where the conditions aresatisfied . Since the 1970s, the debateon levels of selection has kept on growing and extending to differentareas, though no precise consensus has been reached. Positions rangefrom the gene-centered view, where natural selection is taken tooperate almost exclusively at the level of genes , to the pluralistic multilevel selection theory, whichallows for natural selection to operate on any level of the biologicalhierarchy where we find the right kind of units .
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What Other Components Do Cells Have
As previously mentioned, a cell’s cytoplasm is home to numerous functional and structural elements. These elements exist in the form of molecules and organelles picture them as the tools, appliances, and inner rooms of the cell. Major classes of intracellular organic molecules include nucleic acids, proteins, carbohydrates, and lipids, all of which are essential to the cell’s functions.
Nucleic acids are the molecules that contain and help express a cell’s genetic code. There are two major classes of nucleic acids: deoxyribonucleic acid and ribonucleic acid . DNA is the molecule that contains all of the information required to build and maintain the cell RNA has several roles associated with expression of the information stored in DNA. Of course, nucleic acids alone aren’t responsible for the preservation and expression of genetic material: Cells also use proteins to help replicate the genome and accomplish the profound structural changes that underlie cell division.
Proteins are a second type of intracellular organic molecule. These substances are made from chains of smaller molecules called amino acids, and they serve a variety of functions in the cell, both catalytic and structural. For example, proteins called enzymes convert cellular molecules into other forms that might help a cell meet its energy needs, build support structures, or pump out wastes.