WEEK 3&4 (The human genome project)

Question 1

What does alternate splicing allow us to do?

Answer 1

To remove exons for diversity

Question 2

What was the Human Genome project?

Answer 2

A 15-year plan to identify all human genes, map them all and to sequence approximately 3 billion base pairs thought to be comprised by the 24 chromosomes in humans

Question 3

When did the Human Genome Project begin?

Answer 3

1990

Question 4

Which institutes coordinated the Human Genome Project?

Answer 4

• Department of Energy
• National Center of Human Genome Research (division of the National Institutes of Health)

Question 5

Who led the Human Genome Project?

Answer 5

James Watson then Dr Francis Colins

Question 6

What were the Primary goals of the Human Genome Project?

Answer 6

• Establish functional categories for all human genes
• Analyse genetic variations between humans (including the identification of SINGLE-NUCLEOTIDE POLYMORPHISMS)
• Map and sequence the genomes of several model organisms used in experimental genetics
• Develop new sequencing technologies
• Disseminate genome information among both scientists and the general public

Question 7

Give an example of a new sequencing technology that could be developed due to HGP

Answer 7

Highthroughput computer-automated sequencers to facilitate genome analysis

Question 8

What are the major features of the Human Genome?

Answer 8

• Contains 3.1 billion nucleotides
• 99.9% smilier in individuals of all nationalities
• Dynamic
• 20,000 protein-coding genes
• Average size of a human gene is 25kb
• Many human genes produce more than one protein through ALTERNATIVE SPLICING enabling human cells to produce a much larger number of proteins
• 50% of human genes show high similarity to other organisms
• 40% genes have NO KNOWN MOLECULAR FUNCTION

Question 9

How much do protein-coding sequences make up the human genome?

Answer 9

2%

Question 10

What accounts for genome diversity from person to person?

Answer 10

SNPs and COPY NUMBER VARIATIONS (CNVs)

Question 11

What are other properties of the Human Genome?

Answer 11

• Genes are not uniformly distributed on the 24 chromosomes
• GENE-RICH CLUSTERS are separated by gene-poor “deserts” that account for 20% of the genome
• Deserts correlate with G BANDS seen in stained chromosomes

Question 12

Which chromosomes have the highest and lowest gene densities?

Answer 12

• CHROMOSOME 19 = HIGHEST GENE DENSITY
• CHROMOSOME 13 & Y CHROMOSOME = LOWEST GENE DENSITIES

Question 13

Which chromosomes contain the smallest and largest number of genes?

Answer 13

• CHROMOSOME 1 = LARGEST NUMBER OF GENES
• Y CHROMOSOME = SMALLEST NUMBER OF GENES

Question 14

What is the largest known human gene?

Answer 14

Encodes for DYSTROPHIN (a muscle protein) -> Gene associated in MUTANT FORM with MUSCULAR DYSTROPHY is 2.5 Mb in length -> Most of this gene is composed of INTRONS

Question 15

What is the range of introns found in human genes?

Answer 15

0 (histone genes) to 234 (gene for titin)

Question 16

What are some diseases associated with Chromosome 21?

Answer 16

• Down syndrome
• Leukemia
• Deafness
• Epilepsy
• Breast cancer

Question 17

What are Single-nucleotide Polymorphisms (SNPs)?

Answer 17

Single-base changes in the genomes

[variations of many SNPs are associated with disease conditions]

Question 18

What has the innovation of the Human genome project allowed?

Answer 18

The greatly reduced cost of DNA sequencing so that regular people can have their DNA sequenced