A1.2 Nucleic Acids HL

Question 1

Draw a pentose sugar labelled….

Answer 1

….

Question 2

Where can new nucleotides only be added?

Answer 2

New nucleotides can only be added to the 3’ end of a sugar

Question 3

Draw a polymer of nucleotides labelled….

Answer 3

….

Question 4

What does each complementary base pair have?

Answer 4

Each complementary base has one purine (double ring) (A,G) nitrogonous base and one pyrimidine (single ring) (T,C,U) nitrogonous base

Question 5

What enhances stability of a DNA molecule?

Answer 5

-Purine-pyrimidine base pairs
-Nucleosomes

Question 5

Where are nucleosome only found in?

Answer 5

Nucleosomes are only found in Eukaryotes

Question 6

Why do each complementary base pairs have on purine and one pyrimidine?

Answer 6

Each complementary base pair has one purine and one pyrimidine because it creates base pairs that are of equal length, increasing stability of DNA molecule

Question 7

Why are nucleosomes only found in Eukaryotes?

Answer 7

Nucleosomes are only found in Eukaryotes because prokaryotes do not have histone proteins

Question 8

Describe the structure of nucleosomes….

Answer 8

-DNA wraps around 8 histone proteins twice
-Additional H1 histone helps stabilize nucleosome
-Linker DNA links 2 different histone proteins

Question 9

What did the Hershey-Chase experiment prove?

Answer 9

The Hershey-Chase experiment proved that DNA not protein was the genetic material that passed on hereditary information

Question 10

What did Chargaff find out?

Answer 10

-Chargaff found out that there were different amounts of each base in different organisms (not 25%)
-A,T had similar amounts and C,G as well