STUDY OF EFFECT OF SEASONAL VARIATIONS ON THE BODY WEIGHT AND HEIGHT OF UPPER EGYPTION CHILDREN

Abstract

The rate of growth of any individual, and their final height, is dependant upon a complex combination of genetic and environmental factors. Environment produced changes in growth rate do not necessarily lead to alterations in final height because of the process of catch-up growth, Campbell and Mclntoch Neil (1998).

1. Genetic factor:

Hereditary affects not only the end result of growth, but also the rate of progress towards it, and thus the radiological, dental, sexual and neurological ages of identical twins tend also to be identical, whereas those of non identical twins may differ considerably. There is also a strong genetic component in the determination ofbody shape. The control of body size is certainly a complicated affair involving many genes, yet a disturbance in a single gene or group of genes may produce a widespread and drastic effects, as in the condition of achondroplasia, which is inherited as a simple dominant, David Sinclair (1973). Genetic factors probably play the leading part in the difference between male and female patterns of growth. The marked and consistent advancement of girls over boys in respect of skeletal maturation has been attributed to a retarding action of the genes on Y-chromosome of the male. Individuals with the chromosome pattern XXY suffer from what is called Klinefelter's syndrome; they are long-legged. Yet their