model organism

Examples of model organism in the following topics:

• Use of Whole-Genome Sequences of Model Organisms

  • Sequencing genomes of model organisms allows scientists to study homologous proteins in more complex eukaryotes, such as humans.
  • By 1997, the genome sequences of two important model organisms were available: the bacterium Escherichia coli K12 and the yeast Saccharomyces cerevisiae.
  • Much basic research is performed using model organisms because the information can be applied to the biological processes of genetically-similar organisms.
  • It is the most-studied eukaryotic model organism in molecular and cell biology, similar to E. coli's role in the study of prokaryotic organisms.
  • Saccharomyces cerevisiae, a yeast, is used as a model organism for studying signaling proteins and protein-processing enzymes which have homologs in humans.

• Modeling Ecosystem Dynamics

  • Conceptual models describe ecosystem structure, while analytical and simulation models use algorithms to predict ecosystem dynamics.
  • Conceptual models are useful for describing ecosystem structure and dynamics and for demonstrating the relationships between different organisms in a community and their environment.
  • The organisms and their resources are grouped into specific compartments with arrows showing the relationship and transfer of energy or nutrients between them .
  • To model the cycling of mineral nutrients, organic and inorganic nutrients are subdivided into those that are bioavailable (ready to be incorporated into biological macromolecules) and those that are not.
  • Like analytical models, simulation models use complex algorithms to predict ecosystem dynamics.

• Genetic Control of Flowers

  • A variety of genes control flower development, which involves sexual maturation and growth of reproductive organs as shown by the ABC model.
  • the flowers individual organs must grow (modeled using the ABC model)
  • In the simple ABC model of floral development, three gene activities (termed A, B, and C-functions) interact to determine the developmental identities of the organ primordia (singular: primordium) within the floral meristem.
  • Most genes central in this model belong to the MADS-box genes and are transcription factors that regulate the expression of the genes specific for each floral organ.
  • Diagram the ABC model of flower development and identify the genes that control that development

• The Levels of Classification

  • Taxonomy (which literally means "arrangement law") is the science of classifying organisms to construct internationally-shared classification systems with each organism placed into more and more inclusive groupings.
  • Think about how a grocery store is organized.
  • The taxonomic classification system (also called the Linnaean system after its inventor, Carl Linnaeus, a Swedish botanist, zoologist, and physician) uses a hierarchical model.
  • The full name of an organism technically has eight terms.
  • The taxonomic classification system uses a hierarchical model to organize living organisms into increasingly specific categories.

• Limitations to the Classic Model of Phylogenetic Trees

  • The concepts of phylogenetic modeling are constantly changing causing limitations to the classic model to arise.
  • The concepts of phylogenetic modeling are constantly changing.
  • Over the last several decades, new research has challenged scientists' ideas about how organisms are related.
  • New models of these relationships have been proposed for consideration by the scientific community.
  • Many phylogenetic trees have been shown as models of the evolutionary relationship among species.

• Ecological Pyramids

  • Ecological pyramids, which can be inverted or upright, depict biomass, energy, and the number of organisms in each trophic level.
  • Ecological pyramids show the relative amounts of various parameters (such as number of organisms, energy, and biomass) across trophic levels.
  • Pyramid ecosystem modeling can also be used to show energy flow through the trophic levels.
  • However, in the study of energy flow through the ecosystem, pyramids of energy are the most consistent and representative models of ecosystem structure.
  • Ecological pyramids depict the (a) biomass, (b) number of organisms, and (c) energy in each trophic level.

• Food Chains and Food Webs

  • Both energy and nutrients flow through a food web, moving through organisms as they are consumed by an organism above them in the food web.
  • In both food webs and food chains, arrows point from an organism that is consumed to the organism that consumes it.
  • A detrital food web consists of a base of organisms that feed on decaying organic matter (dead organisms), called decomposers or detritivores.
  • These organisms are usually bacteria or fungi that recycle organic material back into the biotic part of the ecosystem as they themselves are consumed by other organisms.
  • Distinguish between food chains and food webs as models of energy flow in ecosystems

• Studying Ecosystem Dynamics

  • Many different models are used to study ecosystem dynamics, including holistic, experimental, conceptual, analytical, and simulation models.
  • A holistic ecosystem model attempts to quantify the composition, interaction, and dynamics of entire ecosystems.
  • A major limitation to these approaches is that removing individual organisms from their natural ecosystem or altering a natural ecosystem through partitioning may change the dynamics of the ecosystem.
  • Three basic types of ecosystem modeling are routinely used in research and ecosystem management: conceptual models, analytical models, and simulation models.
  • A simulation model is created using complex computer algorithms to holistically model ecosystems and to predict the effects of environmental disturbances on ecosystem structure and dynamics.

• Varying Rates of Speciation

  • Scientists around the world study speciation, documenting observations both of living organisms and those found in the fossil record.
  • As their ideas take shape and as research reveals new details about how life evolves, they develop models to help explain rates of speciation.
  • In terms of how quickly speciation occurs, two patterns are currently observed: the gradual speciation model and the punctuated equilibrium model.
  • In the gradual speciation model, species diverge gradually over time in small steps.
  • When a change in the environment takes place, such as a drop in the water level, a small number of organisms are separated from the rest in a brief period of time, essentially forming one large and one tiny population.

• The Carbon Cycle

  • Carbon, the second most abundant element in living organisms, is present in all organic molecules.
  • These organisms eventually form sediments on the ocean floor.
  • Although much of the debate about the future effects of increasing atmospheric carbon on climate change focuses on fossils fuels, scientists take natural processes, such as volcanoes and respiration, into account as they model and predict the future impact of this increase.
  • Photosynthesis converts carbon dioxide gas to organic carbon, while respiration cycles the organic carbon back into carbon dioxide gas.
  • Long-term storage of organic carbon occurs when matter from living organisms is buried deep underground and becomes fossilized.