1. 2.1.1 Mitosis as Part of the Cell Cycle
The Developing Cell
2.1.1 Mitosis as Part of the Cell Cycle

2. (b) Describe the structure of DNA and explain the importance of complementary base pairing and hydrogen bonding

3. Answer as many questions as you can. (you have 10 minutes)
Starter
Answer as many questions as you can. (you have 10 minutes)

4. Introduction to nucleotides
Boardworks AS Biology
Nucleic Acids and the Genetic Code
Nucleotides are nitrogen-containing organic substances that form the basis of the nucleic acids DNA and RNA.
All nucleotides contain the following three groups:
a nitrogen-containing base
a phosphate group
a pentose sugar
Teacher notes
Some nucleotides, such as ATP, contain more than one phosphate group.
A purine base is shown in the diagram – students should not confuse this with the pentose sugar.
In DNA the sugar is deoxyribose, whereas in RNA the sugar is ribose.

6. Boardworks AS Biology Nucleic Acids and the Genetic Code
Bases
There are five bases, split into two types: A G
adenine (A) and guanine (G) are purine bases. T C U
thymine (T), cytosine (C) and uracil (U) are pyrimidine bases.
Teacher notes
Note that carbons have not been included in these diagrams for simplicity.
DNA contains A, G, T and C, whereas RNA contains A, G, U and C.

7. Boardworks AS Biology Nucleic Acids and the Genetic Code
Base pairing rules
Boardworks AS Biology
Nucleic Acids and the Genetic Code
Teacher notes
It should be clarified to students that RNA is single-stranded and so, generally, base pairing does not occur. However, in some cases, such as in tRNA, base pairing does take place.

8. Formation of polynucleotides
Boardworks AS Biology
Nucleic Acids and the Genetic Code
Formation of polynucleotides
Teacher notes
Note that carbons have not been included in these diagrams for simplicity.

9. Which is the correct spelling?
Nucleotide
Nucloetide
Nuclitide

10. What is the definition

11. Which is the correct spelling?
Deoxiribose
Deoxyribase
Deoxyribose

12. What is the definition

13. Which is the correct spelling?
Cystosine
Cytosine
Cystine

14. What is the definition?