الموضوع: الكروسومات
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  #1  
قديم 11-11-2009, 04:52 PM
 
الكروسومات

الكروسومات
الدكتورة رنا الشامي

Chromosomes :
The blocks of genetic material in the nuclei of all cells in the body. They carry the genes – the unit responsible for the transmission of the parental characteristics to the offspring and also for passing on essential information with each cell division during the development of the embryo , during the growth of a baby to an adult , and throughout life . The material that makes up the chromosomes is deoxyribonucleic acid (DNA) .
Human cell contain 23 pairs of chromosomes , 22 are identical pairs , but the 23rd pairs , the sex chromosomes , are identical only in the females , who have two-xx chromosomes . In males the 23rd pairs contains only one x chromosome and a smaller y chromosome . The sex cells themselves ( the spermatozoa and ova ) contain only half the normal number of chromosome – one of each of the 23 pairs – so that when fertilization take place the full complement of 46 is restored .
If this balance disturbed , many congenital defects such as Down s syndrome (mongolism) will be the result , less obvious mutations are also responsible for disorders such as hemophilia and muscular dystrophy.


Other examples :
Calcium : 8.4-10.2mg/dl
Catecholamines
Cerebrospinal fluid pressure 70-180mm
water volume 100-160ml
Ceruloplasmin : 20-46mg/dl
Chloride : 98-106mmol/L
As well as in :
Cholesterol …..
Complement components ….
Copper …
Cortisol …
Creatinine
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