1. DNA was discovered in England?

TrueFalse

False, Most books ascribe the discovery of DNA to Friedrich Miescher who was Swiss

2. Why is the double helix a spiral shape?

Because the bases, wishing to stack on top of each other, distort the backbone into a helical shape

3. In how many ways can the four major bases: adenine, thymine, cytosine and guanine in one chain of the double helix combine with bases in the other chain?

This question was considered to be ambiguous and therefore was disregarded in the competition entries

4. What is an intron and an exon and what are their roles in gene expression?

An intron is an intervening sequence of DNA in the middle of a gene which is not expressed, i.e. represented in the mRNA, and an exon is a segment of a gene which is expressed, i.e. represented in the mRNA.

5. What is the structural difference between uracil and thymine?

6. What is meant by the 3' end and the 5' end of DNA?

The 3' end is the end which carries a ribose with a free (unmodified or unlinked) 3' hydroxyl group; the 5' end is the end which carries a ribose with an unlinked 5' carbon, usually carrying one or more phosphate groups. Polynucleotides are synthesised starting at the 5' end

7. How was the double helix discovered and who discovered it?

"It was discovered by James Watson and Frances Crick by model building based on base ratios and unpublished X-ray diffraction pictures.

8. How many base pairs are there in the human haploid genome?

9. Match the picture of the famous scientist with the correct name below.

1.		2.		3.
4.		5.		6.
James Watson		Rosalind Franklin		Dorothy Hodgkin
Max Perutz		Francis Crick		Maurice Wilkins

Picture 1 is
Picture 2 is
Picture 3 is
Picture 4 is
Picture 5 is
Picture 6 is

10. What is the relationship between the scientist in picture 3 and the scientist in picture 6; and where did they work?

11. From the pictures above who is the odd one out and why?

12. Order the following events that occurred in 1953 from earliest (Jan) to latest (Dec)

1 2 3 4 5		Coronation of Queen Elizabeth II
1 2 3 4 5		Sir Edmund Hilary's expedition is the first to reach the summit of Mount Everest
1 2 3 4 5		England beat Austrailia in the 5th test at the Oval to win the Ashes
1 2 3 4 5		Watson and Crick publish a paper in Nature describing the structure of DNA
1 2 3 4 5		Pierce Brosnan is born

Biochemical Society Education Committee