Key Area 8: Genomic Sequencing

Question 1

Define genomic sequencing

Answer 1

Genomics is the study of genomes. The genome is all the DNA in the nucleus and mitochondria

Question 2

Explain what phylogenetic a is and how it can be used as evidence for evolution

Answer 2

Comparing the genetic sequences of organisms can demonstrate the relatedness of groups of organisms. Phylogenetic trees can be used to measure how related two genomes are. The further apart they are the more distantly related they are.

Question 3

Explain what a molecular clocks are and how they can be used as evidence for evolution

Answer 3

Mutations accumulate at a steady rate over time. Therefore the number of nucleotide substitutions that a genome accumulates is regarded as being proportional to time. By comparing the data with fossil records the molecular clock gives information about how long ago the most common ancestor existed

Question 4

Name the 3 domains of life

Answer 4

Bacteria, archaea and eukaryotes

Question 5

The 3 domains of life

Answer 5

rRNA nucleotide sequences have been studied because they are shared by all living things. Comparison of the sequences has given clues to the evolution of all living things and demonstrated at all life belongs to one of 3 domains

Question 6

Describe 2 benefits of using analysis of an individual’s genome in medicine

Answer 6

1) predictive medicine- once you have your DNA sequence you could look for; disease causing mutations or mutations that increase your likelihood of developing a condition
2) pharmacogenetics- how effective a drug is in any one person is affected by your DNA. Therefore knowing the genome sequence could be used to predict which medicine and which dosage will be most effective in one person compared to another

Question 7

Ethical issues

Answer 7

As a result of advances in this field, a question of ethics has also arisen. Insurance companies, banks and others may decline services or increase premiums as a result of finding less desirable trait.