Unit 2 Genetics: DNA & RNA Quiz Study Guide
Quiz Date: Friday October 30, 2015
*START STUDYING IMMEDIATELY!!!!*
SB2B: Explain the role of DNA in storing and transmitting cellular information.
1. 1. State a role (FUNCTION) for each of three different types of enzymes in DNA replication.
a. DNA helicase: DNA helicase is a molecular enzyme-protein that separates or unzips two strands of
DNA. It runs along the DNA to unzip it, and while doing so, it converts chemical energy into mechanical
energy.
b. DNA polymerase: The DNA polymerases are enzymes that create DNA molecules by
assembling nucleotides, the building blocks of DNA. These enzymes are essential to DNA
replication and usually work in pairs to create two identical DNA strands from one original
DNA molecule. During this process, DNA polymerase “reads” the existing DNA strands to
create two new strands that match the existing ones.
c. DNA ligase: DNA Ligase is an essential enzyme within all cells that seals breaks in the phosphatesugar backbone of DNA. DNA ligase accomplishs three main functions: joining Okazaki fragments, sealing
repairs, and sealing recombination fragments
2 . Which of the following is the correct base-pairing rule for DNA?
A. A-U; C-G
B. A-G; T-C
C. A-T; G-C
D. A-C; T-G
3.
The letters “DNA” stand for Deoxyribonucleic acid.
4.
DNA is composed of smaller subunits know as Nucleotides.
5.
The three parts of a nucleotide are Sugar, phosphate, and a nitrogen base.
6.
The four nitrogen bases that are found in DNA are Adenine, cytosine, guanine, and
thymine.
7.
DNA looks like a ladder twisted into a shape known as a double helix
8.
The two molecules that make up the sides of the ladder or the side portion of a DNA
molecule are Sugars and phosphates.
9.
The molecules that meet across the middle, forming the steps of the “ladder’” are known
as Nitrogen bases.
10.
According to Chargaff’s rules, the percentages of adenine are equal to those of thymine
and the percentages of cytosine are equal to those of guanine in the DNA molecule.
11.
The nitrogen bases are held together in the center of the molecule by Hydrogen Bonds.
12.
The type of sugar found in DNA is Deoxyribose.
13.
If the sequence on the right hand side of the DNA molecule was TAGGCTCA, the
complimentary side would have a sequence of ATCCGAGT.
14.
Label the parts of the
drawing below. Include
all of these terms: nucleotide,
phosphate, sugar, nitrogen
base, hydrogen bond, covalent
bond, purine, pyrimidine,
adenine, thymine, cytosine, and
guanine.
15.
The process in which DNA builds an exact duplicate of itself is known as DNA
Replication.
16.
What is the primary function of DNA?
The primary function of DNA is to store information that tells the cells which proteins to
make.
17.
Why is it so important that the DNA molecule be able to make copies of itself?
Just prior to cell division, the DNA must replicate so that each new daughter cell receives
an exact copy of the genome for that cell. All cells that divide to form new cells must pass
exact copies of their DNA to offspring cells.
18.
During replication, the two nucleotide chains separate and each chain serves as a
template for a new nucleotide chain. This process is known as DNA Replication.
19.
During replication, enzymes called DNA Helicase untwist the double helix, separating
the two parental strands.
20.
Enzymes called DNA Polymerase move along the separated strands assembling the new
chains of DNA.
21.
The letters “RNA” stand for Ribonucleic Acid.
22.
In RNA, adenine always pairs with the nitrogen base known as Uracil.
23.
List three ways that DNA is different from RNA:
(1) DNA HAS THE SUGAR DEOXYRIBOSE AND RNA HAS THE SUGAR RIBOSE.
(2) DNA IS DOUBLE STRANDED AND RNA IS SINGLE STRANDED.
(3) DNA HAS THE NITROGEN BASE THYMINE. RNA HAS N THYMINE, BUT HAS
URACIL INSTEAD.
24.
There are three kinds of RNA. Messenger RNA carries the information from the nucleus
to the ribosome’s in the cytoplasm. Transfer RNA reads the message and binds to the specific
Amino Acids to make the protein. Ribosomal RNA is the most abundant form of RNA and
makes up ribosome’s.
25.
The process of making a strand of RNA from a strand of DNA is called Transcription.
26.
The sequence of nucleotides in mRNA is Translated into a sequence of Amino Acids.
27.
A group of 3 nitrogen bases forms a Codon.
28.
Translation occurs in the ribosomes in the cytoplasm. The DNA in the nucleus tells the
ribosomes which proteins to make and how to make them. In the nucleus, DNA transcribes
RNA. The RNA is then sent to the cytoplasm in the form of mRNA. A combination of three
nitrogen bases is used as a code for each amino acid. This group of three bases is called a
codon. Each codon calls for one amino acid. It takes many amino acids to form a protein.
These amino acids are transported to the ribosomes by tRNA to form proteins
29.
If the sequence on the DNA molecule calls for a protein with the following DNA codons,
(1) what would be the sequence on the mRNA, (2) what would be the sequence on the tRNA,
and (3) what would be the amino acid sequence of the protein being made?
DNA 
TAC
mRNA 
AUG
tRNA 
UAC
Amino Acids: Met
TTA
AAU
UUA
ASP
CAA
GUU
CAA
Val
ACC
UGG
ACC
Trypto
ATA
UAU
AUA
Iso
ATT
UAA
AUU
Asp