Feb. 27, 2020, 6:36 p.m. by Frederick
A Rapid Introduction to Molecular Biology
Making up all living material, the cell is considered the building block of life. The nucleus, a component of most eukaryotic (nonbacterial) cells, has been known to be the hub of cellular activity for 150 years. Seen under a light microscope, the nucleus appears to simply be a darker region of the cell, but as we increase magnification, we find a hodgepodge of substances in the nucleus, which undergoes a flurry of activity leading up to and during mitosis, or cell division; see Figure 1.
An example of an DNA string (whose alphabet contains the symbols A, C, G, and T) is ATGCTTCAGAAAGGTCTTACG.
Given: A DNA string
Return: Four integers corresponding to the number of times that the symbols A, C, G, and T occur in
20 12 17 21