3.1.5.2 DNA replication

Question 1

How is DNA replicated?

Answer 1

semi-conservatively

Question 2

What is formed as a result of DNA replication?

Answer 2

2 double helixes - both consisting of 1original strand and 1 new strand

Question 3

What is the purpose of DNA replication?

Answer 3

ensures continuity of genetic info between generations

Question 4

Semi-conservative replication PROCESS

Answer 4

1. DNA helicase breaks H bonds between complementary base pairs (unwinds double helix)
2. free DNA nucleotides attract to exposed bases and form H bond with complementary bases
3. phosphodiester bonds are formed between adjacent nucleotides (catalysed by DNA polymerase)

Question 5

What are the characteristics of DNA in eukaryotic organisms?

Answer 5

-stored in nucleus
-linear
-very long
-associated with histones

Question 6

What are the characteristics of DNA in prokaryotic organisms?

Answer 6

-no nucleus
-circular
-short
-not associated with protein molecules
-contains plasmids

Question 7

What is an intron?

Answer 7

non-coding sequences of DNA

Question 8

What is an exon?

Answer 8

coding sequences of DNA

Question 9

Why is DNA wrapped around histones?

Answer 9

to pack all the DNA into the chromosomes