Genomes

Question 1

What is the genome?

Answer 1

The total DNA in cell

• nuclear
• organellar DNA

Question 2

What is extracellular/organellar DNA? What are its characteristics?

Answer 2

• mitochondria and chloroplast DNA in the cell
• smaller
• circular
• inherited independently, from mother
• non-recombining (so doesn’t contribute to evolution)

Question 3

What is the C-value?

Answer 3

How much DNA is in the genome. (usually measured as haploid)

Question 4

What is the C-value paradox?

Answer 4

The C-value does not reflect the evolutionary history or any other obvious feature.

Question 5

What is the function of introns?

Answer 5

Allows for alternative splicing

Question 6

What is the function of telomeres?

Answer 6

A long repetitive sequence at the end of DNA , protecting the chromosome.

Question 7

What are mobile elements?

Answer 7

Sequences of DNA that can incorporate themselves into different parts of the genome.

Question 8

What is a transposon?

Answer 8

The DNA is excised from its location by an encoded enzyme, transposase, and then re-inserted back into a different region.

(cut and paste)

Question 9

What is a retrotransposon?

Answer 9

An RNA intermediate is produced from the donor DNA and then reverse transcribed into cDNA which re-inserts into a different genomic location.

(copy and paste)

Question 10

What is the difference between viral and non viral retrotransposons?

Answer 10

non-viral reinserts itself into the genome that it came from, in a different location while viral encodes fro a viral shell, allowing it to leave the cell and infect another cell/organism