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Name: KEY Period: Date:
DNA and RNA Practice
DNA Review
1. What are the monomers of DNA? nucleotides.
2. What are the three parts of a nucleotide, identify the parts labeled below.
A. phosphate group__
B. deoxyribose/pentose sugar
C. nitrogen base
3. Name the 4 nitrogen bases on DNA. Adenine, thymine, guanine, cytosine
4. What is the difference between a purine & a pyrimidine? Purines have 2 rings and pyrimidine’s
have a single ring._________________________________
5. Who is responsible for determining the structure of the DNA molecule? Rosalind Franklin,
James Watson and Francis Crick
6. Which type of bonds holds the DNA bases together? Hydrogen bond
7. Name the complementary base pairs of DNA. adenine and thymine; guanine and cytosine
8. How does the nucleotide sequence in one side of DNA compare with the other side of the DNA
strand? The two chains are complementary to each other.______________
9. Why must DNA be able to make copies of itself? During cell division two identical cells
are produced, each containing one copy of the DNA.
10. What is the function of DNA polymerase? DNA polymerase is an enzyme that adds
complementary bases to the growing strand during DNA replication.
11. If the sequence of nucleotides on the original DNA strand was AGGCTA, what would be the
nucleotide sequence on the complementary strand of DNA? TCCGAT
12. When replication is complete, how do the 2 new DNA molecules compare to each other & the
original DNA molecule? They are identical to each other and to the original strand of DNA.
13. Is DNA replicated (copied) before or after cell division? DNA is replicated before cell division.
14. What is an error in DNA replication called? Mutation_ What helps lower this error rate to 1 in 1
billion nucleotides? DNA polymerase “proofreads” the new strand.
