Introduction to Bio 1

Question 1

virus replication occurs in

Answer 1

viruses

Question 2

How is DNA organised within the interphase nucleus?

Answer 2

in nuclear envelope

Question 3

What is DNA wrapped around

Answer 3

histidine proteins

Question 4

how many left handed turns

Answer 4

1.7

Question 5

Tell me about histidine proteins

Answer 5

Positively charged
Long N-termini
Have amino-terminal tails

Question 6

Whats the role of Histidine H1

Answer 6

helps form 30nm fibre which DNA is packed into and further condensed

Question 7

When does chromosome compaction vary

Answer 7

cell cycle

Question 8

Why do chromosomes need to be remodelled

Answer 8

to allow protein access

Question 9

Tell me about the organisation of the human genome

Answer 9

often repetitive
junk DNA
Genes < 5%
3 billion base pairs of DNA

Question 10

Repetitive DNA: Interspersed repeats

Answer 10

SINE and LINE often derived from retroviruses

Question 11

Tandem Repeats

Answer 11

Satellites
Mini-satellites (7-100 bases repeated up to 40,000 bases)
Micro-satellites (1-6 bases repeated > 100 bases)

Question 12

Mitochondrial DNA

Answer 12

circular
maternally inherited
Implications of disease
Forensics - more abundant than nuclear DNA

Question 13

Post-translational modifications

Answer 13

P = phosphorylation 
M = Methylation
A = acetylation (decreases the positive charge - decreases the affinity for 02)
K = Lysine
R = arginine 
S = serine

Question 14

Nucleoside

nucleotide

Answer 14

base + sugar

base + sugar + phosphate

Question 15

Whats the difference between Uracil and Thymine

Answer 15

thymine has a methyl group

Question 16

What do chromosomes do in their most condensed stage of cell division

Answer 16

they spread and are stained with Giemsa

Question 17

Tell me about chromosomes painting

Answer 17

unique probes linked to different fluorescent tags (short, single stranded DNA sequence that are unique sequences on each chromosome)

Question 18

What allows individuals to be distinguished

Answer 18

variations in short tandem repeat numbers.

Shorter repeat lengths migrate more quickly by electrophoresis