The characteristics, advantages and applications of each developmental model organism are described

Biologists conduct scientific research on selected biological species to reveal a certain life phenomenon with universal laws, and in this case, the selected biological species is a model organism. For example, Mendel used peas as experimental materials to reveal the genetic laws of the biological world, while Morgan used fruit flies as experimental materials, and in their research, peas and fruit flies are model organisms for studying the genetic laws of organisms. Due to evolutionary reasons, the basic mode of many life activities is conserved in various biological species on Earth, which is the basic basis for the success of model organism research strategies.

The choice of a model organism depends first on what scientific question the researcher wants to solve, and then on the species that can best help solve the problem. In the late 19th and early 20th centuries, it was discovered that the problem of developmental phenomena could be partially answered if the focus was on relatively simple organisms. Because these organisms are easier to observe and experimentally manipulate, in addition to genetic research, model organism research strategies have been widely used in developmental biology, and some species are recognized as excellent model organisms, such as nematodes, fruit flies, Xenopus laevis, salamanders, mice, etc.

With the completion of the Human Genome Project and the advent of the post-genomic research era, more attention has been paid to model organism research strategies. The structure and function of genes can be studied in other suitable organisms, and the physiological and pathological processes of human beings can also be simulated by suitable organisms.

At present, the most widely used model organisms in the field of population and health include bacteriophages, Escherichia coli, Saccharomyces cerevisiae, Caenorhabditis elegans, sea urchins, fruit flies, zebrafish, Xenopus toads, and mice. It is more commonly used in botanical research, such as Arabidopsis thrain, rice, etc.

With the development of life science research, new species will be used as model organisms. But they will have some basic things in common:

2) harmless to humans and the environment, easily accessible and easy to raise and breed in the laboratory;

3) Short generations, many offspring, and clear genetic background;

4) Easy to perform experimental operations, especially with genetic manipulation methods and phenotypic methods.

Development refers to the development of life phenomena, which is the change of an organism from the beginning of its life to its maturity, and the process of self-construction and self-organization of biological organisms. Pick D. Stalls.

a。No, it is stupid and new, but mature.

b。to the end of flowering.

c。Start with fertilization.

First of all, mutation is indefinite, and whether it is beneficial depends on whether this mutation adapts to the environment and provides primitive materials for biological evolution, and then overbreeding provides the impetus for natural selection, using the struggle for survival as a means to achieve the survival of the fittest and the elimination of the unfit

Therefore, c

From an evolutionary point of view, the diversity of biological traits is the result of (the result of the selection of organisms in different directions due to the environment or the result of natural selection) stupid chains.

Due to the variety of environmental conditions on the earth, the results of natural selection will inevitably lead to a variety of biological worlds.