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What is Plants breeding positives negatives selection?
Either positive or negative traits could be selected for in nature, although selection for negative traits is extremely rare. A good example of positive selection at a rapid pace can be seen in antibiotic resistance in bacteria. Negative selection usually occurs in domesticated plants and animals. Let's say you have a very tasty strain of tomatoes. Instead of keeping some so you have seeds for next year you eat, sell or can all of them. This leaves you with no seeds, therefore you've selected out the positive traits of that particular plant. I think this is what you are referring to.
Which kind of selection eliminates extreme phenotypes?
disruptive selection
What type of selection is this?
directional selection
How does selection in natural selection works?
Some individual organisms are better equipped to live and reproduce in their environment than others. If what makes them better equipped is heritable, their offspring will be more numerous and will tend to inherit the same traits or qualities themselves. The opposite will happen to those poorly equipped. They will have fewer or no offspring, and their negative traits will tend to disappear from the population as time goes on. These two tendencies are called positive (natural) selection and negative (natural) selection respectively. Natural selection is always relative to the environment. What is advantageous in one environment may not be so in another, and what is disadvantageous (deleterious) in one environment may not be so in another.
What are the three patterns of of natural selection?
directional selection,stabilizing selection, anddisruptiveselection
What is a positive selection vector?
positive selection vector
What is negative selection of immunology?
Immunology relies on both negative selection and positive selection. Negative selection, or non resultant, provides for discounting a method of treatment. Positive selection, or improvement can at times be found by elimination through negative selection.
Alloreactivity is a positive selection step or negative selection step?
Neither. Alloreactivity has to do with a lymphocytes reacting to a foreign antigen. Positive and negative selection are processes of central tolerance which is to say that they deal with a T cell's ability to bind self-antigen.
Which year was natural selection proposed?
Im not positive but im pretty sure it was 1859 by Darwin
T cells undergo positive selection in the thymus which means?
T cell undergoes maturation in the thymus and one of the tests it must pass to mature into a single positive mature naive T cell is positive selection. In positive selection your body is making sure that the T cell that it produces is reactive to your own MHC. If it cannot bind to your own MHC, the T cell is useless and it will just die by neglect in your thymus. In positive selection the T cell is "tickled" with thymic endothelial cells that express your own MHC class 1 and MHC class 2. If there is an affinity of the T cell to bind to your MHCs it will continue to the next step in maturation which is negative selection. If the T cell binds way too strongly to your MHC it will also die. There is a specific range that it must bind to your own MHC for it to continue.
What is Plants breeding positives negatives selection?
Either positive or negative traits could be selected for in nature, although selection for negative traits is extremely rare. A good example of positive selection at a rapid pace can be seen in antibiotic resistance in bacteria. Negative selection usually occurs in domesticated plants and animals. Let's say you have a very tasty strain of tomatoes. Instead of keeping some so you have seeds for next year you eat, sell or can all of them. This leaves you with no seeds, therefore you've selected out the positive traits of that particular plant. I think this is what you are referring to.
What has the author Katherine Joanne Hare written?
Katherine Joanne Hare has written: 'Microenvironmental regulation of thymocyte positive selection'
What role do alleles play in natural selection?
Genes are the medium by which inherited traits are passed on to offspring. It is inherited traits, and thus genes, that receive positive or negative selection.
Does thymic selection destroy MHC molecules?
The thymus goes through a positive and negative selection for T cells. T cells will respond to MHC class 1, either ignore if self or activate to destroy if foreign.
Where can I find cheap 20 inch rims ?
Walmart has a nice selection of rims. If you prefer to shop online for your new set of rims, tirerack.com has affordable rims and they have many positive reviews. Wheelstudio.com also has a good selection and offers free shipping in the U.S.
Who sells motorcycle tires online?
http://www.motorcycle-superstore.com/ has a good selection. They have an overall 94% positive rating with geenral postive reviews of their store and service on bizrate.
What is the difference between selection and recruitment?
Recruitment is a positive process that involves searching and encouraging as much people to apply for a certain post. Selection, on the other hand, is a negative process since it involves rejection of unsuitable applicants and chooses ones most suitable person for the job.
