7. Genome Structure

Question 1

What is a genome?

Answer 1

Full complement of DNA for an organism

Question 2

What forces hold DNA together?

Answer 2

3’-5’ phosphodiester bonds
Base stacking=van der Waals
Hydrogen bonding between nucleotides

Question 3

What is a nucleosome made up of?

Answer 3

DNA wrapped around an octamer of histones

Question 4

What are the steps from basic helix to a chromosome?

Answer 4

Basic helix
Nucleosome
Chromatin
Scaffold
Loops
Chromosome

Question 5

What are H3 and H4 histone tails rich in?

Answer 5

Lysine

Question 6

What happens when lysine tails are acetylated?

Answer 6

Positive charge changed to neutral
Promotes looser DNA structure
Aids transcription

Question 7

What are centromeres?

Answer 7

Sections of repetitive DNA that mitotic spindles attach to

Question 8

What are telomeres?

Answer 8

Cap at the end of chromosomes of repetitive DNA

Question 9

What is heterochromatin?

Answer 9

High condensed
Dark giemsa stain
No transcription
Gene poor

Question 10

What is euchromatin?

Answer 10

Extended
Light giemsa stain
Active transcription
Gene rich