CMB2000/L14 Genomics & Genome Projects

Question 1

Give the timeline of the Human Genome Project. (5)

Answer 1

1990 - aim to map/sequence entire human genome
1995 - first complete bacterial genome sequenced
1996 - information freely available
2000 - Working draft 90% of genome with 99% accuracy
2003 - Project declared complete with 99.99% accuracy

Question 2

Give 2 reasons to sequence the genome.

Answer 2

Higher order structure
Chromosome maintenance
Comparative searches

Question 3

Describe how the genome sequence is obtained. (4)

Answer 3

Obtain organism’s genomic DNA
Break DNA into small fragments
Obtain DNA sequence from all fragments
Search for overlaps to ‘reconstruct’ genome sequence

Question 4

Give 3 features of model organisms.

Answer 4

Small genome
Easy to manipulate
Provide information on fundamental biological processes

Question 5

Describe the bacterial infection in Europe in 2011.

Answer 5

50 deaths, 1000s of infections
Genome sequence obtained in <2 days
Identified new strain of E. coli
Insight into antibiotic resistance characteristics
Insight to why bacteria was so virulent and targeting adults

Question 6

Describe the Black Death and how sequencing helped.

Answer 6

1347-1351 killed 30-50% Europeans (30 mil)
Yersinia pestis isolated and sequenced
Revealed that modern day ancestors have no unique sequence differences so other factors contributed to outbreak

Question 7

Describe the Plague of Justinian and how sequencing helped.

Answer 7

Killed 100 million in 541-543AD
Genome sequence isolated afrom teeth of victims
Revealed Yerstinia pestis was causative agent
Revealed that 541-543 strain vanished and 1347-1351 was completely new strain

Question 8

Describe the Human Genome Project (HGP) as a comprehensive genome map.

Answer 8

Provided a detailed map of the human genome, identifying approximately 20-25,000 genes

Question 9

Explain how the HGP aided technological advancements.(2)

Answer 9

Spurred development of high-throughput sequencing technologies, bioinformatics tools and data storage solutions
Reduced cost and time for DNA sequencing

Question 11

How many different reading frames are there and how are they determined?

Answer 11

6 reading frames
By start codon AT

Question 11

How did the HGP aid scientific discoveries?

Answer 11

Identified genetic variants associated with diseases, enhancing understanding of genetic health and disease

Question 11

Describe how the HGP inspired collaborative efforts.

Answer 11

Fostered international collaboration among scientists, leading to establishment of global databases and resources like Ensembl genome browser

Question 12

What occurs every 50 codons?

Answer 12

Random start codon

Question 13

Describe a short open reading frame.

Answer 13

Start ATG
Stop TAA
Encoding only ~2 amino acids
Several throughout genome

Question 14

Give 3 limitations of the HGP.

Answer 14

Incomplete coverage - repetitive regions e.g., centromeres and telomeres, gaps in data
Genetic variation - doesn’t capture extent of human genetic diversity
Functional understanding - many identified genes have unknown factors

Question 15

Describe S. cerevisiae genomics.

Answer 15

Tightly packed genes with little repetitive DNA
Rarely that RNA alternative splicing occurs
Simple genetics performed to analyse gene function

Question 16

Give 3 advancements pioneered by the HGP.

Answer 16

Foundation for precision medicine
Gene therapy
Genetic screening
Several open databases being accessible
Comparative genomics

Question 17

Give 2 findings of genome sequencing rare childhood conditions.

Answer 17

1/4 intensive care patients had a genetic disorder
66% cases mutation occurred spontaneously
Diagnosis in 2-3 weeks avoiding further invasive tests sometimes led to treatment change