Biological Organisms

7 Key excerpts on "Biological Organisms"

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  Biology as a natural science: The study of life in all its forms

  • Saket Kushwaha(Author)
  • 2023(Publication Date)
  • Delve Publishing

    (Publisher)

  This branch of science studies all live things or living beings. It focuses on and studies topics relating to living beings such as life organization, functions, patterns and order of organisms, growth and development of living organisms, etc. Living things come in all sorts of sizes, forms, and purposes, and biologists study life from the tiniest cell to the largest ecosystems. As a result, biology has many branches and divisions, including evolutionary biology, cellular biology, genetics, growth and developmental biology, and so on. 1.1. INTRODUCTION Microorganisms are assumed to have been the original lifeforms on the planet, existing billions of years before animals and plants evolved. The animals, birds, and flowers humans know and love are all very recent, having evolved between 130 and 200 million years ago. Humans have been on this earth for the last 2.5 million years, and only in the last 200,000 years have humans begun to appear as humans do now. Biology is the study of living things. What is the definition of life? This could appear to be a foolish question with an apparent answer, yet defining life is difficult. For example, virology is a discipline of biology that examines viruses, which have some of the properties of living beings but lack others. Viruses, despite their ability to assault live beings, inflict illnesses, and even reproduce, do not fit the requirements that biologists use to define life. Biology has grappled with four questions since its inception: What are the common characteristics that make anything “alive”? How do the various living things work? When confronted with the incredible diversity of life, how can we organize the many types of organismsso that we can better understand them? Finally, scientists want to know how this variety arose and how it is maintained. As new organismsare found day after day, scientists continue to seek answers to these and other issues.

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  Ocean Ecology

  Marine Life in the Age of Humans

  • J. Emmett Duffy(Author)
  • 2021(Publication Date)
  • Princeton University Press

    (Publisher)

  112 T he individual organism is the fundamental unit of biology and ecology. Individual plants transform light and inorganic materials into life, other organisms consume that living matter and energy and transform it into their own forms of life, and still others close the loop by decomposing it back into inorganic materials. The activities of organisms link the different levels and processes of ecology, from environment, to population, to community and ecosystem, inter-acting with one another, creating habitats, and altering the composition of seawater and atmosphere ( figure 5.1 ). In this chapter we review the basic features of how individual organisms work, which provides a foundation for understanding their interactions in populations, communities, and ecosystems. We consider the organism from two complementary perspectives: functionally, as a chemical reactor; and historically, as the product of an evolutionary process. First, like the rest of the universe, living organisms are composed of matter, differentiated into chemical elements and powered by energy. We review how energy and materials are captured, stored, and used by organisms, how the rates of eco-logical processes are affected by the fundamental environmental and biological variables of tempera-ture and body size, and the special challenges and solutions of autotrophs (plants) and heterotrophs. We then turn to the unique feature that distinguishes life from nonliving matter: the capacity of living organisms to adapt to the environment through changes in their genetic code or genome —a set of editable instructions that guide the organism’s self-construction, the way it captures energy and ma-terials from the environment, and its other affairs. That mutable code allows regular updates to the population’s operating system, so to speak, adapting it to changing environments.

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  Foundations of Biophysics

  • A. L. Stanford(Author)
  • 2013(Publication Date)
  • Academic Press

    (Publisher)

  ''Life'' is an abstract word and has to be defined in abstract terms—primarily through concrete examples. It is usually accepted that one can distinguish living from nonliving matter. Biologists have established a set of characteristics whose presence or absence determines the distinction. These characteristics— reproduction, growth, metabolism. C H A R A C T E R I S T I C S O F L I F E 5 and responsiveness —are technical terms with specific meanings to the biologist. Reproduction That a living system can reproduce itself is an absolute requirement for its continued existence, since the thesis of biogenesis (that all things living today come only from living things) is universally accepted today. This is consistent with present knowledge, in that living organisms have not yet been produced in the laboratory. Sexual reproduction is accomplished when an ovum, or egg cell, is fertilized by a spermatozoon, the male reproductive cell. The resulting fertilized cell is called a zygote. Asexual reproduction occurs in lower life forms when the union of gametes (either ova or sperm-atozoa) is not involved. This form of reproduction is accomplished by processes like fission (the splitting of a mature cell into two or more parts) or by budding (in which the new individual arises from an outgrowth or bud from the parent). Figure 1-1 illustrates budding in one of the lower forms of fife. Growth However produced, a daughter organism grows and develops into a mature individual with forms and functions similar to those of its parents. Biological growth differs from that of a crystal or a sand castle. Crystal growth or sand castle growth occurs by accretion, in which ready-made material outside the structure is assimilated into it. Biological growth, on the other hand, occurs from within the system. Growth of living organ-isms is based on synthesis, the formation of complex materials from simpler materials.

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  Philosophical Essays

  In Honor of Edgar Arthur Singer, Jr.

  • F. P. Clarke, M. C. Nahm, F. P. Clarke, M. C. Nahm(Authors)
  • 2017(Publication Date)
  • University of Pennsylvania Press Anniversary Collection

    (Publisher)

  In short, the organism is a physico-chemical system of a certain kind. 5 One thing upon which all of these investigators seem to agree has been summed up by Sharp in these words: It is with protoplasm that the phenomena of life, in so far as we know them, are invariably associated. T h e y probably would agree with his further statement: The complex behavior of the living organism can receive scien-tific explanation (i.e., be fitted into an orderly scheme of antecedents and consequents), if at all, only on the basis of the constitution and properties of the materials composing protoplasm; the structural organization of protoplasm; the relation of the reactions and re-sponses of protoplasm in the form of organized units or cells to the environmental conditions; the chain of energy changes occurring in connection with all of the organism's activities; and the correla-tion of all these conditions and events. But the exact determination of this basis must await the dis-covery of better methods, methods which will not result in 'Quoted from Introduction to Cytology, by L. W. Sharp, p. 51. BIOLOGICAL PHENOMENA 95 the death of the subject and the consequent invalidation of the results. We must conclude, therefore, that any justifiable use of the statement, living can be distinguished from non-living because the former is composed of protoplasm and the latter is not, lies in the future. T h e use of certain functions of living organisms as distin-guishing processes peculiar to them alone has thus far not been very successfully employed, although it is not infrequently the case that a number of functions are listed in general texts as characteristic of life. Metabolism (including growth), repro-duction, and irritability are probably those most often men-tioned. Adaptation, rhythmicity, and contractility are given in a long list of characteristics, submitted by C. G. Rogers in his Textbook of Comparative Physiology.

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  Growing Explanations

  Historical Perspectives on Recent Science

  • M. Norton Wise, Barbara Herrnstein Smith, E. Roy Weintraub(Authors)
  • 2004(Publication Date)
  • Duke University Press Books

    (Publisher)

  I have argued that this opinion can be contested for several reasons. First, even though one embraces the standard view of the definition of life, one does not necessarily deny that ‘‘living processes’’ may be defined, demarcated, or characterized in a general way, for example, through a list Explaining Emergence in Artificial Life 315 of shared properties of living beings, even though such a list may be vague, incomplete, redundant, or may not constitute a set of universally necessary and su≈cient conditions. Second and more important, because of the manifold character of re-search, definitions of scientific concepts cannot be restrained to a single type of definition (e.g., operational, mathematical, ostensive, Aristotelian, ontological, or whatever). Talking about biological life is talking about a very general set of objects—the whole subject matter of the biosciences— and we should not too rigidly demand precise definitions, especially where the cognitive and theoretical function of an ontodefinition serves as a root metaphor for the whole field. In contrast to the standard view, we have nevertheless seen that general notions of life can be explicated with some theoretical precision. Third, biology in the twentieth century has not only been empiricist and fact-oriented, but has given us rich conceptual tools to construct a co-herent picture of at least some of the universal properties of living systems (cells, multicellular organisms, and systems of such organisms), viewed within an evolutionary frame as evolved, highly organized, adaptive sys-tems with some autonomy and specific informational properties, that is, with properties that are emergent but no less material than chemical and physical properties. In this sense, organisms are genuine ontological units, and well defined as objects of biology.

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  Fundamental Generation Systems

  Computer Science and Artificial Consciousness, the Informational Field of Generation of the Universe, the Sixth Sense of Living Beings

  • Alain Cardon, Abdelkhalak El Hami(Authors)
  • 2023(Publication Date)
  • Wiley-ISTE

    (Publisher)

  There is therefore an informational relationship between the generation plan and the informational set of the context, from the outside. To create a new species, a series of males and females must be generated, forming a first group of individuals of the species that will be able to amplify by similar reproductions, which is something a local generation anomaly in a reproduction cannot do. We must therefore consider that life was created on Earth by a bifurcation of the organizational law that formed all the material elements in the space of the Universe. The organizational law will engage on the Earth to create elements with physical membranes that reify their informational envelopes, giving them the capacity to generate generational plans for their reproductions. We thus have a global living system all over the planet, which we can call the Gaia system. In this approach, the definition of a living organism is therefore the following. 5.2.8.1. An evolved living organism An evolved living organism is a complex autonomous system endowed with autonomy, which has a physical body membrane that is unified with its informational envelope, possessing an architecture composed of organs that must maintain its active self by cellular regeneration, which is designed to conserve its energy by either directly consuming photonic energy, like The Informational Interpretation of Living Things 91 plants, or by eating other organisms, like all mobile organisms. It must also reproduce itself by its strong tendency to do so. These organisms are in direct communication with each other in their geographical domains, using their senses and their limbs to move. They are elements that are part of groups, the whole forming a set that is in a continuous deployment organization. We can provide a very important property of the life of living organisms, which is of course applied to humans.

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  The Sciences

  An Integrated Approach

  • James Trefil, Robert M. Hazen(Authors)
  • 2022(Publication Date)
  • Wiley

    (Publisher)

  This narrowing leads ultimately to the familiar two-part scientific names of organ- isms. When you go to a zoo or read a biology textbook, you will probably notice that the scientific names of plants and animals are given in terms of two Latin words— Homo sapiens or Tyrannosaurus rex, for example—that indicate the genus and species. (By convention, the two words are italicized and the genus is capitalized.) This binomial nomenclature is an important legacy of Linnaeus’s work. Biologists have traditionally considered the kingdom to be the broadest classification, corresponding to the coarsest division of living things. Until the 1960s, most biologists recognized only two kingdoms—plants and animals. In subsequent decades, most biolo- gists classified living things into five kingdoms (Figure 20-6), though, as we shall see, this view is also changing as new data come to light. In the five-kingdom scheme, two of the kingdoms consist primarily of single-celled organisms. 1. Monera. Single-celled organisms without an internal structure called the cell nucleus (see Chapter 21). Monera, many of which are commonly called bacteria, are the most primitive living things (Figure 20-7). 20.3 | Classifying Living Things 555 2. Protista. Mainly single-celled organisms with a cell nucleus, but also a few multicellular organisms that have a particularly simple structure (Figure 20-8). The remaining three kingdoms in this classification scheme include multicellular organisms, in which several different kinds of interdependent cells combine in a single species. Members of these kingdoms are distinguished primarily by the way that they obtain energy. 3. Fungi. Multicellular organisms that get their energy and nutrients by absorbing materials from their environment. 4. Plants. Multicellular organisms that get their energy directly from the Sun through photosynthesis.

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