The ECM commands the EVAP Purge Solenoid OFF once the system has reached a predetermined level of vacuum. This test verifies if a vacuum can be achieved in the EVAP system. Failure to develop a vacuum may be caused by a large leak or a restriction.
Our subspecies has evolved since 500 years ago. As one example, take the changed prevalence of genetic diseases. As these are caused by alleles (and therefore the frequency of the relevant alleles has changed), and evolution is the change in allele frequencies in gene pools over generations, this is biological evolution. Humans are apes.
A gene is a stretch of DNA or RNA that determines a certain trait. Genes mutate and can take two or more alternative forms; an allele is one of these forms of a gene.For example, the gene for eye color has several variations (alleles) such as an allele for blue eye color or an allele for brown eyes.An allele is found at a fixed spot on a chromosome. Chromosomes occur in pairs so organisms have two alleles for each gene â one allele in each chromosome in the pair.n allele is found at a fixed spot on a chromosome. Chromosomes occur in pairs so organisms have two alleles for each gene â one allele in each chromosome in the pair.