Name _____________________
Date_______
DNA Reinforcement
DNA STRUCTURE –
1. Watson and Crick discovered that the DNA molecule was shaped like a(n) ________.
2. The DNA molecule has __________ strands.
3. Each strand is a long chain of ____________ units.
4. These units that consist of a nitrogenous base, deoxyribose and a phosphate group
are called ______________.
5. Strands of DNA are held together by hydrogen bonds between the
____________ _________.
6. In the bonding between the nitrogenous bases of the DNA strands, adenine bonds
only with _____________ and cytosine bonds only with _____________.
7. The idea of the bonding of nitrogenous bases came about because of
_____________ Rule which stated that the amount of Adenine is always equal to
the amount of ______________ and the amount of guanine is always equal to the
amount of ______________.
8. The following diagram shows the nucleotide sequence of a segment of a DNA strand.
FILL in the complementary nitrogen bases of the second strand. Also, LABEL the
phosphate groups and Deoxyriboses.
Replication
REPLICATION –
9. When DNA makes an exact copy of itself, each old strand serves as the _________,
and the new strand is ______________ to the old strand.
10. What is the goal of replication? ______________________________________
11. Fill in the diagram below to show how replication occurs.
12. How did the new molecules you completed compare to the original? ____________
13. What is the name of the enzyme that assists in DNA replication? _____________
14. What four bases make up the DNA code? _______ , _______, _______, _______
15. How do the 4 bases of the code pair up in the DNA molecule and what type of bond
holds them together? _____________________________________________
______________________________________________________________
16. During DNA replication, what sequence on the complementary base pairs will be
matched to the following sequence: ATACGCGTTA
_____________________________________