The order of these smaller molecules, or organic bases, acts as a code for genetic information. When a gene is dominant, the trait it controls will be present every time the gene is present. The brown gene is dominant. When a gene is recessive, it must be paired with a second recessive gene before its effect will be expressed. The blue gene is recessive.
Environmental forces continue to modify inborn potentials with each passing year.
Consistent differences in temperament can be detected for at least the first 2 years of life. Nutrition - has bearing on hereditary size 2. Timing - retarded language ability between 6 mos. and 3 years interferes with inherited tendency to be a good public speaker. Disease Intrauterine environment . Prenatal environment of the womb is protected and stable, but a number of conditions can affect embryonic or fetal development before birth if mother's health or nutrition is poor, if she contracts certain diseases, such as German measles or syphilis, uses drugs, or is exposed to X-rays or atomic radiation, the fetus may be harmed.