Answer: A. Log file
Explanation:
a file that records either events that occur in an operating system
Every cell of the organism has the same DNA sequence and same genes. However, not all genes are expressed in every single cell at the same time. Only those genes necessary for a specialised function of a specialised cell are expressed in the specialised cell. For example, skin cells have some different proteins than nerve cells. Genes responsible for those "skin proteins" are activated in skin cells and are turned off in nerve cells.
Substances that are made up of only one type of atom.
The jet stream flows west to east
A blue shift is any decrease in wavelength, with a corresponding increase in frequency, of an electromagnetic wave; the opposite effect is referred to as red shift. In visible light, this shifts the color from the red end of the spectrum to the blue end.