Nucleic acids allow organisms to transfer genetic information from one generation to the next. There are two types of nucleic acids: deoxyribonucleic acid, better known as DNA and ribonucleic acid, better known as RNA.When a cell divides, its DNA is copied and passed from one cell generation to the next generation. DNA is organized into chromosomes and found within the nucleus of our cells.here are two types of nucleic acids: deoxyribonucleic acid, better known as DNA and ribonucleic acid, better known as RNA. When a cell divides, its DNA is copied and passed from one cell generation to the next generation.
Cramps usually begin one to two years after a woman starts getting her period. Pain usually is felt in the lower abdomen or back. They can be mild to severe. Common menstrual cramps often start shortly before or at the onset of the period and continue one to three days.
By Mayo Clinic Staff. During your menstrual period, your uterus contracts to help expel its lining. Hormone-like substances (prostaglandins) involved in pain and inflammation trigger the uterine muscle contractions. Higher levels of prostaglandins are associated with more-severe menstrual cramps. Severe contractions may constrict the blood vessels feeding the uterus. The resulting pain can be compared to the chest pain that occurs when blocked blood vessels starve portions of the heart of food and oxygen. Menstrual cramps may also be caused by: Endometriosis.