Name: ____________________________________________________ Period: ____________ Date: ________________
DNA and RNA Review
Standards: 5a, 5b
Objective: Students will be able to compare and contrast DNA and RNA.
Directions: Read the passage below. Then answer the questions in complete sentences.
Watson and Crick determined that DNA is a molecule that is a double helix—two strands twisted around each other,
like a winding staircase. Each strand is made of linked nucleotides. Nucleotides are the subunits that make up DNA. Each
nucleotide is made of three parts: a phosphate group, a five-carbon sugar molecule, and a nitrogen base. The five-carbon
sugar in DNA nucleotides is called deoxyribose, from which DNA gets its full name, deoxyribonucleic acid
Like DNA, ribonucleic acid (RNA) is a nucleic acid— a molecule made of nucleotides linked together. RNA differs
from DNA in three ways. First, RNA consists of a single strand of nucleotides instead of the two strands found in DNA.
Second, RNA nucleotides contain the five-carbon sugar ribose rather than the sugar deoxyribose found in DNA
nucleotides. And third, RNA has a nitrogen base called uracil—abbreviated as U—instead of the base thymine (T) found
in DNA. No thymine (T) bases are found in RNA. Like thymine, uracil is complementary to adenine whenever RNA
base-pairs with another nucleic acid.
1.
What is a nucleotide?
2.
Label parts of the nucleotide as: nitrogen base, phosphate, and sugar.
3.
Complete the table below.
(deoxyribose or ribose)
DNA
RNA
Abbreviation stands for…
Function
# of nucleotide strands
Type of sugar present
List 4 types of nitrogen bases
A=
A=
G=
G=
T=
U=
C=
C=
mRNA=
How many types of this
nucleotide?
Only 1.
tRNA=
rRNA=
Directions: In the spaces provided, write “D” if the statement is true of DNA. Write “R” if the statement is true of RNA.
Write “B” if the statement is true of both DNA and RNA.
4.
______ consists of a single strand of nucleotides
8.
______ contains ribose
5.
______ made of nucleotides linked together
9.
______ is a nucleic acid
6.
______ contains deoxyribose
10. ______ consists of a double strand of nucleotides
7.
______ has the nitrogen base uracil
11. ______ contains a base that pairs with adenine
12. What are the base pairing rules?
13. Complete the table for the complimentary Base Pairing Rules.
DNA
RNA
adenine (A)  __________________________
adenine (A)  __________________________
cytosine (C)  __________________________
cytosine (C)  __________________________
14. Use the base pairing rules to write the complementary strands to the following DNA template.
a. T A G C T A C G G A C T
b. A A T A C G G T C C T A
15. Complete the table below.
3 Types of
RNA
mRNA
rRNA
tRNA
Abbreviation stands for
Function