ساينس الصف الثالث الاعدادي – الفصل الدراسي الاول ساينس تالتة اعدادي – ترم اول In This part we will study : 1-Somatic cells are divided by mitosis which leads to the growth of living organisms and compensation of the damaged cells. 2-Reproductive cells are divided by meiosis which leads to the formation of male and female gametes which are responsible for reproduction in living organisms and the transfer of genetic traits from parents to their offspring. Chromosomes General structure of the chromosome : 1- The chromosome consists of two connected threads at the centromere point each thread is called a chromatid. 2-The chromosome chemically consists of nuclear acid called D.N.A and protein. DNA carries the genetic traits of the organism. 3- Centromere it is the point of connection the two chromatid Chromosomes: They are thread like bodies present in cell’s nuclei and they represent the genetic material of the living organism. Centromere; It is the point of connection of the two chromatids of chromosome during the cell division. Types of cell divison 1 – Mitosis 2 – Meiosis لمتابعة مستر احمد الباشا وكل ما يخص الساينس : جروب الفيس بوك http://bit.ly/2Of1mcN صفحة الفيس بوك http://bit.ly/2Gq5xMo بالتوفيق مستر احمد الباشا