The word allele is a short form of allelomorph (other form, a word coined by William Bateson and Edith Rebecca Saunders), which was used in the early days of genetics to describe variant forms of a gene detected as different phenotypes.
Causes. Male sexual arousal is a complex process that involves the brain, hormones, emotions, nerves, muscles and blood vessels. Erectile dysfunction can result from a problem with any of these. Likewise, stress and mental health concerns can cause or worsen erectile dysfunction.Sometimes a combination of physical and psychological issues causes erectile dysfunction.For instance, a minor physical condition that slows your sexual response might cause anxiety about maintaining an erection.rectile dysfunction can result from a problem with any of these. Likewise, stress and mental health concerns can cause or worsen erectile dysfunction. Sometimes a combination of physical and psychological issues causes erectile dysfunction.
The causes of erection problems can be physical, psychological, or a combination of the two. Physical causes of erection problems are more common in older men. They occur because of disorders that can affect the nerves and blood vessels responsible for causing an erection. 1  Physical causes of erectile problems include: 2  heart disease. 3  atherosclerosis (hardening of the arteries). 4  high blood pressure. 5  diabetes. 6  obesity. 7  high cholesterol. 8  Parkinsonâs disease.