Answer:
Biomedical models can be of many types—from animal models of human diseases to animal, in vitro, or modelling systems for studying any aspect of human biology or disease. A detailed discussion of various types of models appeared in a National Research Council study, Models for Biomedical Research (NRC 1985), and is appended to this report.
Explanation:
A biomedical model is a surrogate for a human being, or a human biologic system, that can be used to understand normal and abnormal function from gene to phenotype and to provide a basis for preventive or therapeutic intervention in human diseases. For example, characterization of mouse models of various dwarfing syndromes, cloning of mutated genes, and parallel comparative genetic mapping and cloning of genes for similar human syndromes have led to an understanding of various human dwarfing conditions and have suggested therapies based on biologic knowledge, rather than shotgun testing. Mouse models with targeted mutations in the cystic fibrosis gene are providing a means for testing gene therapy delivered by aerosol into the lungs (Dorin and others 1996). The use of nonhuman primates that are genomically similar is beginning to shed light on complex human diseases. Squid giant axons are important model systems in neurobiologic research because their size allows a variety of manipulations not possible with vertebrate axons and because there are 40 years of data on the anatomy, physiology, biophysics, and biochemistry of those neurons. Clams, sea urchins, and fishes are models in developmental biology (for example, for study of transcriptional regulation during early cell differentiation) because they have high fecundity, short generation times, and transparent eggs that develop externally.
