WorksheetsFINAL: DNA Structure & Replication Class Worksheet #2—Test
Total questions: 43
Worksheet time: 22mins
Which three parts make up a nucleotide?
Sugar, base, enzyme
Phosphate, ribosome, base
Phosphate, sugar, nitrogen base
Sugar, lipid, base
What is the basic unit (monomer) of DNA?
Amino acid
Nucleotide
Protein
Sugar
What type of sugar is found in DNA?
Ribose
Glucose
Deoxyribose
Sucrose
Which nitrogen base pairs with adenine in DNA?
Cytosine
Guanine
Thymine
Uracil
Which base pair is held together by three hydrogen bonds?
A–T
T–A
C–G
A–C
The sides (backbone) of the DNA ladder are made of:
Nitrogen bases
Hydrogen bonds
Sugars and phosphates
Proteins
The rungs of the DNA ladder are made of:
Sugar-phosphate bonds
Complementary base pairs
Phosphate groups
Enzymes
DNA strands run in opposite directions. This is described as:
Parallel
Identical
Antiparallel
Complementary
What is the overall shape of DNA?
Straight ladder
Single helix
Double helix
Circular
Which statement best describes complementary base pairing?
Bases pair randomly
A pairs with G and C pairs with T
A pairs with T and C pairs with G
All bases pair equally
What is DNA replication?
DNA being repaired
DNA being translated
DNA being copied
DNA being condensed
During which phase of the cell cycle does DNA replication occur?
G1
S
G2
M
Which enzyme unwinds and “unzips” DNA during replication?
DNA polymerase
RNA polymerase
DNA helicase
Ligase
What type of molecule is DNA helicase?
Lipid
Carbohydrate
Enzyme
Nucleotide
What happens first during DNA replication?
Free nucleotides attach
Hydrogen bonds form
Hydrogen bonds break
New DNA strands join
Free nucleotides attach to exposed DNA bases using:
Random pairing
Hydrogen bonding rules
Complementary base pairing
Sugar bonding
Why is DNA replication called semi-conservative?
DNA is only copied halfway
One new strand is shorter
Each new DNA has one original strand
DNA is conserved in the nucleus
Each new DNA molecule produced contains:
Two original strands
Two new strands
One original and one new strand
No original strands
How does semi-conservative replication help prevent mutations?
It shortens DNA
It removes damaged DNA
It uses original strands as templates
It stops replication errors
What holds newly formed base pairs together in DNA?
Covalent bonds
Ionic bonds
Hydrogen bonds
Peptide bonds
What term describes loose DNA inside the nucleus?
Chromosome
Chromatin
Sister chromatid
Centromere
When DNA is condensed and visible, it is called a:
Chromatin fiber
Chromosome
Nucleotide
Base pair
The cell cycle is best described as:
DNA replication only
Cell division only
A repeating process of growth and division
Protein synthesis
Which stages together make up interphase?
G1, S, G2
S and M
G2 and M
Prophase and metaphase
During which phase does the cell grow and carry out normal functions?
S
G1
G2
M
What happens during G2 phase?
DNA replicates
Cell divides
Cell prepares for division
Chromosomes separate
Sister chromatids are:
Two different chromosomes
Identical copies of a chromosome
Unreplicated DNA
RNA molecules
What structure holds sister chromatids together?
Spindle fiber
Hydrogen bonds
Centromere
Ribosome
Replicated chromosomes are often drawn as an X shape because:
They are twisted
They are broken
They consist of two sister chromatids
They are circular
During which phase do chromosomes first become visible?
S phase
G1 phase
Prophase
G2 phase
According to Chargaff's Rule, if a DNA sample is 30% adenine, thymine will be:
20%
30%
40%
60%
If cytosine makes up 22% of a DNA sample, guanine will be:
11%
22%
44%
78%
Why do base percentages vary between species?
DNA shape changes
Number of chromosomes differs
Genetic sequences are different
Base-pair rules change
Which relationship is always true in DNA?
A = C
T = G
A = T
A = G
Base-pair rules help ensure:
DNA stays short
DNA mutates frequently
Accurate DNA replication
DNA forms RNA
During DNA replication, what is the role of the template strand?
It joins Okazaki fragments
It provides the pattern for building a new strand
It adds RNA primers
It seals DNA fragments
Semi-conservative replication means that:
DNA is copied only once
Each new DNA molecule contains one original strand and one new strand
Only half the DNA is copied
DNA is conserved in the nucleus
Why does complementary base pairing help ensure accurate DNA replication?
It speeds up protein synthesis
It prevents helicase from working
It allows correct nucleotides to match the template strand
It forms RNA primers
Which feature is shared by BOTH DNA and RNA?
Both contain thymine
Both are double-stranded
Both are made of nucleotides
D. nucleus
Which statement best describes how DNA, RNA, and ribosomes work together to make proteins?
DNA leaves the nucleus and builds proteins on ribosomes
RNA stores genetic information permanently
RNA carries instructions from DNA to ribosomes, where proteins are made
Ribosomes copy DNA into RNA
Why is the lagging strand synthesized in fragments?
DNA polymerase moves randomly
DNA polymerase only works in the 5′ → 3′ direction
Helicase skips sections
Primase stops early
Okazaki fragments are:
RNA primers
Short DNA segments on the lagging strand
Enzymes
Hydrogen bonds
Which sequence correctly shows the order of events during DNA replication?
DNA polymerase → primase → helicase
Primase → helicase → DNA polymerase
Helicase → primase → DNA polymerase
DNA ligase → helicase → primase
