The menstrual cycle, which is counted from the first day of one period to the first day of the next, isn't the same for every woman. Menstrual flow might occur every 21 to 35 days and last two to seven days. For the first few years after menstruation begins, long cycles are common.
Definition: DNA (deoxyribonucleic acid) is a type of macromolecule known as a nucleic acid. It is shaped like a twisted double helix and is composed of long strands of alternating sugars and phosphate groups, along with nitrogenous bases (adenine, thymine, guanine and cytosine).
A chromosome is an organized structure of DNA and protein that is found in cells. A chromosome is a single piece of coiled DNA containing many genes, regulatory elements and other nucleotide sequences.he difference between DNA and a chromosome has to deal with an intermediary-genes. DNA is deoxyribonucleic acid, which is a nucleic acid. It is made up of four bases-adenin â¦ e, cytosine, guanine and thymine. When these four bases are arranged in a segment, it is called a gene.