Genome Entries 1

Chapter 15: Sex

Matt Ridley starts off the the chapter by introducing two different genetic diseases; Prader-Willi syndrome and Angelman's syndrome. Children with Prader-Willi syndrome are born floppy and pale-skinned, refused to feed on breast milk but feed uncontrollably on food so much that they become obese, have small hands and feet, and have undeveloped sex organs. Angelman's syndrome is the complete opposite of Prader-Willi syndrome as the child becomes extremely thin, hyperactive, insomniac, small headed, long jawed, they move and laugh goofy, but they don't learn to speak, and are mentally retarded. Both of these syndromes sometimes appear in the same family tree. It is later discovered that in both syndrome, a same chunk of chromosome 15 was missing, but in Prader-Willi, the missing chunk was from the father chromosome while the mother chromosome was missing for the Angelman syndrome. This lead to a conclusion by scientist that genes remembers which parent it came because of its paternal imprint or maternal imprint. The imprinted version is switched on and the other versions is switched off in order for the body to express one gene. If it inherits from the father it will most likely cause Prader-Willi and if its from the mother it will cause Angelman syndrome. Anothe example is patneral genes that are inherit from the father are responsible for making the placenta and the maternal gene is responsible for making the head and brain of the embryo. This shows that our parents genes can affect and determine who we are as a person.