Epigenesis Character Analysis
a) Transposons …show more content…
Epigenesis is the study of how children can inherit and express seemingly new traits from their parents without changes in the underlying DNA. Epigenesist are suggesting that food, lack of exercise etc… is not the only cause of obesity in children. If a pregnant lady eats junk and unhealthy food during pregnancy then it will affect the metabolism of the body. This is so because the change express in the epigenetic gene causes the metabolism to slow down. The slow metabolism does not let the food digest as quick, so it is stored as fat causing excess fat. An example is with the mice in the book. A gene, Agouti is in charge of coat color, obesity and likelihood of cancer. They rats that their gene is expressed or unmethylated have a yellowish coat and are obese while rats with a methylated gene have brown coats and are not …show more content…
a) The Hayflick limit is the number of times human cells can divide before it stops. The limit on cellular reproduction in humans is 52-60 times. This limit is caused by the loss of telomeres, which minimizes DNA information loss. Telomeres provide blank slots that can replace the bits of DNA that are gradually reduced as a cell divides.
b) Both cancer cells and stem cells use an enzyme called telomerase to fix their telomeres and become “immortal.” It is considered immortal because they override the hayflick limit and keep on dividing.
c) Size relates to life expectancy because the larger the species the longer the mammal lives. They have a longer life expectancy because they make a superior ability to repair DNA. Smaller organisms have evolved to live shorter lives because they are at greater risk of being eaten. For example, a Broiler chicken has a shorter life span of 10 weeks because they are slaughtered every 8-10 weeks.
20. The author uses the iPod analogy to explain the method of aging and why it has to happen. Aging is an important part of evolution because like iPods, older versions (older humans) are cleared to make room for better models and new features (better-adapted humans). Old and dying humans (iPods) are infested with diseases and sickness (viruses and bugs) so they die out and leave room for the better models and