8.3 Using genome projects

Question 1

Define genome

Answer 1

All the genetic material in an organism

Question 2

What does the human genome consist of?

Answer 2

Over 3 billion base pairs organised into around 20000 genes

Question 3

What technique does determining the complete DNA base sequence of an organism use?

Answer 3

Whole-genome shotgun (WGS) sequencing

Question 4

What are the steps involved in DNA seqeuncing?

Answer 4

1. Cutting the DNA into overlapping fragments short enough for sequencing
2. Clone the fragments in plasmid or other vectors
3. Sequence each fragment
4. Order the sequences into one overall sequence with computer software

Question 5

What were sequencing methods like in the past?

Answer 5

Labour-intensive, expensive, could only be done on a small scale

Question 6

What were sequencing methods like now?

Answer 6

Continuously updated and have become automated
- Cost-effective and done on a large scale

Question 7

Define proteome:

Answer 7

All the proteins in a given type of cell or organism at a given time under specified circumstances

Question 8

What does determining the genome of simpler organisms allow?

Answer 8

Allows the assignment of proteins to each gene in the genome (proteome), creating a database

Question 9

Why is this (simple organisms) easy to do?

Answer 9

• The vast majority of prokaryotes have just one, circular piece of DNA that is not associated with histones
• None of the non-coding portions of DNA

Question 10

How can vaccines develop?

Answer 10

By identifying the protein antigens on the surface of viruses/pathogenic bacteria

Question 11

Why can the knowledge of the genome not be easily translated into the proteome for complex organisms?

Answer 11

Due to the presence of:
- Non-coding DNA
- Regulatory genes - determine when the genes that code for particular proteins should be switched on and off