Genomes

Question 1

C paradox

Answer 1

Why are genomes different sizes?
- little correlation between size and complexity

Question 2

Transposons

Answer 2

• DNA sequences that can change position
• movement can cause mutations and cancers, in which case prevention of their mobility is favored

Question 3

New genes

Answer 3

• duplication in non-coding sequences -> base changes -> translocation -> near the promoter region for transcription of a gene

Question 4

Horizontal gene transfer

Answer 4

• e.g. passing of DNA through tick bites in cows leading to 25% shared DNA with snakes
• generally through parasites or symbiotes

Question 5

eDNA

Answer 5

environmental DNA: info is extracted non-invasively, often in aquatic systems

Question 6

Human genomes and variance

Answer 6

• our genomes vary by 0.1% on average
• we are still evolving!
• e.g. gene in Tibetans living at high altitudes to promote RBC production
• selection for genes that affect replication of lung cells in East Asians due to history of coronavirus
• skin pigment variety due to need for UV protection (too much melanin impairs vitamin D biosynthesis)