PHP â Sort Functions For Arrays. In this chapter, we will go through the following PHP array sort functions: sort() â sort arrays in ascending order. rsort() â sort arrays in descending order. asort() â sort associative arrays in ascending order, according to the value.
Environmental factors that can affect gene expression. Exposing a fetus, infant, or child to a chemical or nutritional (or other) stressor during development can affect the risk of disease development even into adulthood. The mechanisms involved are probably epigenetics (Boekelheide et al. 2012).
Diagram showing at which stages in the DNA-mRNA-protein pathway expression can be controlled. Regulation of gene expression includes a wide range of mechanisms that are used by cells to increase or decrease the production of specific gene products (protein or RNA), and is informally termed gene regulation. Repressors bind to the Operator, coding sequences on the DNA strand that are close to or overlapping the promoter region, impeding RNA polymerase's progress along the strand, thus impeding the expression of the gene.The image to the right demonstrates regulation by a repressor in the lac operon.