DNA Structure and Replication-BIOL-107
DNA Structure and Replication
Question 1
What are the three molecular components of a nucleotide?
glucose, amino acids and phosphate groups
glucose, nitrogen bases and phospholipids
deoxyribose, nitrogen bases and phosphate groups
deoxyribose, amino acids and phospholipids
Question 2
What is the difference between a purine and a pyrimidine?
Pyrimidines are nitrogen bases composed on two rings; purines are nitrogen bases composed of one ring.
Purines are nitrogen bases composed of two rings; pyrimidines are nitrogen bases composed of one ring
Question 3
The two purines bases in DNA are:
cytosine
adenine
guanine
thymine
Question 4
In DNA base pairing, A pairs with ______ and G pairs with ______
U, T
C,T
T,C
G, U
Question 5
What components make up the backbone (the outside of the strands) of the DNA molecule?
deoxyribose and phosphate groups
nitrogen bases and phosphate groups
deoxyribose and nitrogen bases
Question 6
The two strands of DNA run into the opposite directions, this is called …..
Perpendicular
Antiparallel
Two-way
Parallel
Question 7
If the sequence of bases in one strand of DNA is 5′ TAGCCT3′, the sequence of bases in the complementary strand will be
5’AGGCTA3′
5’ATCGGA3′
5’AUCGGA3′
5’TCCGAT3′
Question 8
What kind of bonding between complementary nitrogen bases hold the two strands of the DNA molecule together?
ionic
hydrogen
polar covalent
covalent
Question 9
What are the three steps in DNA replication?
i. Ribosomes are attached to the DNA molecule at the start sequence.
ii. The enzyme, helicase, unwinds the DNA molecule.
iii. Free nucleotides match with complementary bases in the DNA strands.
iv. Amino acids are used to hold nucleotides in place.
v. The phosphate of the new nucleotide is attached to the deoxyribose sugar of the adjacent nucleotide on the same strand
i. Ribosomes are attached to the DNA molecule at the start sequence.
ii. The enzyme, helicase, unwinds the DNA molecule.
iii. Free nucleotides match with complementary bases in the DNA strands.
iv. Amino acids are used to hold nucleotides in place.
v. The phosphate of the new nucleotide is attached to the deoxyribose sugar of the adjacent nucleotide on the same strand
iii
i
iv
ii
v
Question 10
Where in the eukaryotic cell does DNA replication occur?
on the ribosomes
on the cytoplasmic side of the plasma membrane
in the nucleus
in the cytoplasm
Question 11
A random change in the sequence of the DNA that becomes permanent is called
a mutation
nucleotide erroneous
an endonuclease
Question 12
The product of DNA replication is
two molecules of DNA one of which has two old strands and one of which has two new strands
two identical molecules of DNA each having one new and one old strand
two non-identical molecules of DNA
homologous chromosomes
two similar DNA molecules
Question 13
What enzyme is responsible for adding new nucleotides to a growing DNA chain during replication?
restriction endonuclease
ligase
protease
DNA polymerase
Question 14
In DNA replication, one of the two parent strands is made in fragments. This strand is called the ____________ strand.
lagging
leading
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