Every human being starts of as 1 single cell, and it contains every single genetic instruction to construct that human being. These instructions are in 3 billion pairs of nucleotides (DNA base pairs),there are also around 30000 genes, organized in 23 pairs of chromosomes for a total of forty six. One set of chromosomes will come from the mother, and another set from the father.Chromosomes contain information that determines us as a person. As for traits, the dominant traits are always more influential than recessive.
Scientists first discovered that only 3 percent of our DNA contains instructions for building cells, and decided to call the rest as junk DNA, DNA which doesn't help nor hinder our lives. However, later studies have discovered that these DNA are actually traces of past viruses or bacteria that have been in our body. They are now called non-coding DNA.
For a long time scientists also believed that genetic mutations which occurred in ones genes were only from accidents. Such as exposure to radiation or sunspots. However, Barbara McClintock discovered otherwise, she found jumping genes in corn and discovered that their whole sequence of DNA moves from one place to another, and has erratic behavior.This also explained why scientists thought that there were once more than 100000 genes in a human body, one for each specific job/trait, now it is only estimated to be around 30000, since McClintock discovered that through the shuffling of these genes, they can do a huge amount of different things.
Scientists also conclude that genes can adapt to its environment. John Cairns once fed only lactose to a E. Coli bacteria (a food digesting bacteria), and discovered that the bacteria underwent mutations to become lactose tolerant.This shows that genes can determine and choose whether or not they want to mutate.
The best example of these shifting and jumping genes would be the human immune system. Why is it that after contracting chicken pox for the first time, it is near impossible to get it another time in your life? This is because the human body has genes which create antibodies to fight foreign invaders such as viruses and bacteria, and genes adapts to fight against new types of viruses by creating different antibodies.
Scientists first discovered that only 3 percent of our DNA contains instructions for building cells, and decided to call the rest as junk DNA, DNA which doesn't help nor hinder our lives. However, later studies have discovered that these DNA are actually traces of past viruses or bacteria that have been in our body. They are now called non-coding DNA.
For a long time scientists also believed that genetic mutations which occurred in ones genes were only from accidents. Such as exposure to radiation or sunspots. However, Barbara McClintock discovered otherwise, she found jumping genes in corn and discovered that their whole sequence of DNA moves from one place to another, and has erratic behavior.This also explained why scientists thought that there were once more than 100000 genes in a human body, one for each specific job/trait, now it is only estimated to be around 30000, since McClintock discovered that through the shuffling of these genes, they can do a huge amount of different things.
Scientists also conclude that genes can adapt to its environment. John Cairns once fed only lactose to a E. Coli bacteria (a food digesting bacteria), and discovered that the bacteria underwent mutations to become lactose tolerant.This shows that genes can determine and choose whether or not they want to mutate.
The best example of these shifting and jumping genes would be the human immune system. Why is it that after contracting chicken pox for the first time, it is near impossible to get it another time in your life? This is because the human body has genes which create antibodies to fight foreign invaders such as viruses and bacteria, and genes adapts to fight against new types of viruses by creating different antibodies.
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