positive selection and negative selection

It is a process of selective improvement of a crop. In selection, a plant is selected based on its genotypic and phenotypic characters in order to improve some of its characters in its next generatio..

Selection is an important technique in plant breeding. It involves picking the healthiest and the best ones out of the entire crop and reproducing them under controlled condition..

It is a process of selective improvement of a crop. In selection, a plant is selected based on its genotypic and phenotypic characters in order to improve some of its characters in its next generation. Natural selections have occurred in many crops, where som..

Agriculturists and farmers select component crops for mixed cropping based on certain criteri..

Mass Selection - Desirable plants are selected purely based on phenotype and pooled. They are allowed to be grown in mass in next generation. Further selections are made in 3-4 such generations to consolidate desirable characters by ignoring plants with undesirable cha..

Desirable plants are selected purely based on phenotype and pooled. They are allowed to be grown in mass in next generation. Further selections are made in 3-4 such generations to consolidate desirable characters by ignoring plants with undesirable character at each s..

Clonal Selection - B and T lymphocytes have specific receptors on their surface. In B cells, this receptor is the antibody produced by that cell. When this receptor interacts with the antigenic determinant specific to it, the B lymphocyte becomes activated and divides to form a clone of c..

B and T lymphocytes have specific receptors on their surface. In B cells, this receptor is the antibody produced by that cell. When this receptor interacts with the antigenic determinant specific to it, the B lymphocyte becomes activated and divides to form a clone of cells. These cells also gets t..

The selectivity of a catalyst is its ability to make a reaction proceed in a particular direction to yield a particular product. This aspect of a catalyst can be well understood with examples. Example 1: The reaction of CO with H 2 yields different products when different catalysts are ..

It is primarily a process of differential reproduction. Some members of a population may have genes, which enable them to grow up and reproduce at a higher rate. This results in the formation of offspring having better chances of survival. Those organisms that produce large number of viable offspr..