7.4.1 The Human Gene Pool

Question 1

human genome project

Answer 1

• The purpose of the Human Genome Project is to sequence all of the genes in a human.
  • There are approximately 3 billion nucleotides in the human genome.
  • The techniques for sequencing the human genome are based on the Sanger technique combined with advanced computer processing.
• The goal of the Human Genome Project is to sequence all of the genes in a human. In the 1960’s Watson and Crick found that the human genome is made up of DNA, which is a double helix that consists of four main nucleotides: adenine (A), thymine (T), cytosine (C), and guanine (G). The information in DNA is determined by the sequence of these nucleotides in the genome.
• There are approximately 3 billion genes in the human
  genome. This is an extraordinarily large number of
  nucleotides. For comparison, it would take 200 New York City telephone books to hold 3 billion typed letters. The Human Genome Project is a task of immense proportion.

Question 2

Sanger technique

Answer 2

• The techniques for sequencing the human genome are based on the Sanger technique. A sample of human DNA is exposed to restriction enzymes and the reaction products are used in gel electrophoresis. The gel can be read as a sequence of nucleotides. Powerful computers are then used to look for overlapping regions of sequence and aid in piecing together
  different DNA samples.
• The implications of the Human Genome Project are great. For example, a gene called MLH1 that has been implicated in colon cancer is found on chromosome 3. The Human Genome Project will provide the sequence of MLH1. Knowing the DNA sequence may lead to a better understanding of the protein MLH1 produces, possibly leading to a cure for the genetic disease.
• The results of the Human Genome Project will be
  controversial. For example, it will bring up the question of “ownership” of genes. It will also bring up the debate of whether or not insurance will be denied based on genetic code.
• One of the most important concepts to recognize when considering the results of the Human Genome Project is that the DNA among humans only varies by 0.1%.

Question 3

It would take ___________________ New York City telephone books to contain the nucleotide sequence of the human genome.

Answer 3

• 200

Question 4

True or false?

Knowing the DNA sequence of a gene that is implicated in a particular disease may lead to a cure for the disease.

Answer 4

• true

Question 5

(The) ___________________ was / were used to determine the sequence of nucleotides in the human genome.

Answer 5

• Sanger technique

Question 6

MLH1 has been linked to which of the following diseases?

Answer 6

• colon cancer

Question 7

There are approximately _____________________ nucleotides in the human genome.

Answer 7

• three billion