1. In the name of GOd In biology and genetics, the germline of a mature or developing individual is the line (sequence) of germ cells that have genetic material that may be passed to a child Wikipediabiologygeneticsdevelopinggerm cells

2. Germ line versus somatic cells The germ line is present from the very start, when an egg and a sperm fuse. As the cell starts to divide and develop into an embryo, germ cells are specifically set aside; these cells will later generate eggs or sperm in the adult organism that the embryo will eventually become. The non-germ cells, known as somatic cells, will become various structures in the body. Somatic cells contain complete copies of the genome, but they differentiate to perform different functions, developing into neurons, muscle cells, bone cells, and so forth. http://www.wisegeek.com/what-is-a-germ-line.htmembryosomatic cellsgenomebone cells

4. Embryonic Stem Cells(ESCs) Blastocyst (5-7)- Embryonic stem cell Gonadal ridge (6 weeks )- Embryonic germ cells – Primordial germ cells – Germ cells (association with somatic cells of the gonad ) – (HEGCs) which are also stem cells, originate from the primodial germ cells of the gonadal ridge of 5-9- week old fetuses – Pluripotent stem cells – Produce cells of all three germ layers

5. Which mutation will passed down to next generations? While somatic cells arise from the germ line, they are not part of it. Mutations to the somatic cells cannot be passed on to future generations, while changes to the germ line will be perpetuated. Some researchers have theorized that this could be valuable for gene- based therapies; in germ line gene therapy, changes could be made to the lineage of cells which contain genetic information that will be passed down.gene therapy

6. A germ line mutation will not affect the body of the organism the mutation occurs in, but … A germ line mutation will not affect the body of the organism the mutation occurs in, but it will have an impact on the organism's offspring. For example, if a problem occurs during production of egg or sperm cells and that particular egg or sperm happens to become part of a zygote, this problem will impact the baby. A simple example of such a mutation is trisomy, in which someone inherits three chromosomes instead of two because two chromosomes failed to separate during the production of egg or sperm cells.zygotetrisomychromosomes

7. The germ line also provides a wealth of information about inheritance In addition to being of interest from a medical perspective, the germ line also provides a wealth of information about inheritance. Changes can be tracked through the germ line to learn more about the history of an organism, and this lineage of cells can also be used to look at relationships between different groups of individuals. Humans, for example, share a common germ line even though it has diverged in a wide variety of directions as new human generations have been born

8. خواهشمند است کاربران محترم نظرات اصلاحی خود را به آدرس esfandiari@med.mui.ac.ir و یا شماره تلفکس 7922517 ارسال فرمایند.