DNA: The Molecule of Heredity/Instructions to Build Proteins
1. A nucleotide is made of three parts: a ___Phosphate_____ group, a five carbon
_Sugar___,(ribose or deoxyribose) and a nitrogen containing _Base_ (A,C, G, T - or U if RNA).
2. In a single strand of DNA, the phosphate group binds to the __Sugar__ of the next group.
3-4. Chromosomes consist of what two substances: _DNA_ & __Protein_________
5. DNA was not thought to be the genetic blueprint originally; instead many scientists
hypothesized that ___Proteins__ contained the genetic code and blueprint of life. (They were
later proven wrong.)
6. Purines (A and G) have _2_ rings, and pyrimidines (T and C) have __1_ ring.
7. Chargaff's rule states that the DNA of any species contains equal amounts of __Thymine_ &
_Adenine_ and also equal amounts of _Guanine__ & _Cytosine_
8. Franklin studied the structure of DNA using __X-ray crystallography_and determined that
the shape of the molecule was a __helix__
9. James Watson and Francis Crick amended Franklin’s conclusions and determined that the
shape of the molecule was instead a _Double Helix_
10. In DNA, thymine is complementary to __Adenine__ ; cytosine is complementary to
_Guanine__
11. Number the steps of DNA replication in the correct order (1, 2, 3)
__2__Daughter strands are formed using complementary base pairing.
__1___ DNA unwinds
__3___ The DNA of the daughter strands winds with its parent strand.
12. Write the complementary sequence for the following DNA strand:
CCT AAG TCT CGA ATA CCC GGT TAC
GGA TTC
AGA GCT TAT GGG CCA ATG
13. The two sides of the DNA helix are held together by __Hydrogen_bonds.
14. Write out the complete name for DNA: __Deoxyribonucleic acid__
15. Name the scientist(s) responsible for each of the following discoveries.
__Chargaff__________ Certain DNA bases had a one to one ratio
__Griffith___________ Transforming principle (rats/ S & R pneumonia)
__Hershey-Chase_____ DNA as genetic material (bacteriophage/ P& S)
__Watson, Crick (and Franklin)_ The shape of DNA was a double helix
16. Put the diagrams of DNA replication below in the order in which they would occur during
DNA replication.
OLD
___C__
___B__
17-21. Complete the chart comparing DNA and RNA.
Nucleic Acid
DNA
5 –Carbon Sugar
deoxyribose
Nitrogen Bases
A,C,T,G
#of Strands
2
Purpose
Heredity info; protein instructions
Types
DNA
__A___
RNA
ribose
A,C,G,U
1
Protein synthesis
mRNA, rRNA, tRNA
22. Color: P – yellow; D – white; A – Red; T – Blue; C – Orange; and G - Green