Week Six (Genomes and their Evolution)

Question 1

Where gene density differs

Answer 1

Gene density is higher in prokaryotes
More density density variability in eukaryotes (due to presence of introns)

Question 2

Where genome size differs

Answer 2

Genome size more variable in eukaryotes

Question 3

Where gene number differs

Answer 3

Different peaks (eukaryotic has bigger base)

Question 4

Alu elements

Answer 4

10% of genome
May help regulate gene expression

Question 5

LINE1 Transposons

Answer 5

17% of genome
May contribute to neuron development

Question 6

Transposable elements impact on genome

Answer 6

• Can create translocation by unequal crossing over (deletion and duplication)
• Can disrupt/inactivate genes (no proteins produced)
• Can increase/decrease gene expression

Question 7

Types of repetitive DNA

Answer 7

Large segment duplication (one region to another)
Simple sequence DNA (repeats, further divided to short tandem repeats)

Question 8

Where is simple sequence DNA found

Answer 8

Found near telomeres playing a structural role

Question 9

Mechanisms of how gene structure can change

Answer 9

Translocation and fusion (lead to emergence of new species)
Nondisjunction (one set provides function while the other mutates)
Unequal crossing over (duplications and deletions)
DNA polymerase slip during replication (short tandem repeats)

Question 10

How multigene families and new proteins can evolve

Answer 10

Same ancestrial gene expressed at different development stages
Duplications result in mutations
Exon shuffling, duplication and deletion leading to mutation