*2.4.1 Factors controlling growth*

The aspects of growth are influenced by genetic mechanism, which is polygenic in nature. The first mechanism is the regulation of the rate cellular multiplication, affecting the overall size. The second is the control of the pace of maturation [35]. Both x and y chromosomes contain growth regulating genes. The special influence of X-chromosome is referred to in growth studies in females, asaril, girls develop 2 years earlier than boys [36]. Genetic factors such as body size are also known to be influenced by race. Black children stature and pace of osseous maturation during the childhood years.
