Promoter sequences define the direction of transcription and indicate which DNA strand will be transcribed; this strand is known as the sense strand. Many eukaryotic genes have a conserved promoter sequence called the TATA box, located 25 to 35 base pairs upstream of the transcription start site.romoter sequences are typically located directly upstream or at the 5' end of the transcription initiation site.
Popular Answers. Positive selection: also called (Darwinian selection) variants that increase in frequency until they fix in the relevant population. The selective pressure that leads to this fixation is termed positive selection. Negative selection: Also called purifying selection, it means that selection is purging changes that cause deleterious impacts on the fitness of the host. ...
D. Overproduction of offspring. Darwin's theory of natural selection states that species tend to overproduce due to limiting resources. This sets up competition or a struggle for existence. Those most fit in that environment are likely to survive, passing those favorable genes on to their offspring. In time, a new species evolves from the accumulation of favorable genes. Punctuated equilibrium is a theory that was formulated after Darwin's theory and it states that species remain relatively stable for long periods of time and then, due to some natural catastrophe, change rapidly in a short period of time.