DNA is the fundamental genetic material present in all living cells and carries the hereditary information that determines the characteristics of an organism. DNA is located in the cell nucleus and consists of units called nucleotides arranged in a double helix structure. DNA contains genes, which are responsible for traits such as eye color, hair color, and height. DNA directs protein synthesis, which performs vital functions such as building tissues, regulating biological processes, and supporting chemical reactions. It also ensures the transmission of genetic traits from parents to offspring during reproduction. Any change in DNA is called a mutation, which may be beneficial, harmful, or neutral. Some mutations cause genetic diseases, while others contribute to adaptation and evolution. Therefore, DNA is the foundation of life and plays a critical role in growth, development, and body functions.
  الهدف الرابع : التعليم الجيد