BIO BEYOND GENETIC REPLICATION TEST
PAPER 2026 QUESTIONS WITH COMPLETE
SOLUTIONS COMPREHENSIVE STUDY
GUIDE GRADED A+
⩥What technique was most helpful to Watson and Crick in developing
their model for the structure of DNA?
Answer: X-ray crystallography
⩥A scientist assembles a bacteriophage with the protein coat of phage
T2 and the DNA of phage T4. If this composite phage were allowed to
infect a bacterium, the phages produced in the host cell would have
__________.
Answer: the protein and DNA of T4
⩥What is the major difference between bacterial chromosomes and
eukaryotic chromosomes?
Answer: Bacteria have a single circular chromosome, whereas
eukaryotes have several linear chromosomes.
⩥The role of DNA polymerases in DNA replication is to __________.
Answer: attach free nucleotides to the new DNA strand
,⩥Who is credited with discovering the structure of the DNA double
helix?
Answer: Watson and Crick
⩥The two strands of a DNA double helix are antiparallel. This means
that __________.
Answer: one strand runs in the 5' to 3' direction and the other runs in the
3' to 5' direction
⩥The experiments of Meselson and Stahl showed that DNA
Answer: replicates in a semiconservative fashion
⩥The rate of elongation of a DNA strand in prokaryotes is __________
the rate in eukaryotes.
Answer: much faster than
⩥DNA polymerase adds nucleotides to the __________ of the leading
strands and to the __________ of the lagging strands (Okazaki
fragments).
Answer: 3' end; 3' end
⩥Which of the following statements concerning the structure of DNA is
correct?
,Answer: Adenine forms two hydrogen bonds with thymine; guanine
forms three hydrogen bonds with cytosine.
⩥Once the DNA at the replication fork is unwound by helicases, what
prevents the two strands from coming back together to re-form a double
helix?
Answer: Single-strand binding proteins bind the unwound DNA and
prevent the double helix from re-forming.
⩥What enzyme joins Okazaki fragments?
Answer: DNA ligase
⩥Chargaff found that in DNA samples,___________.
Answer: the ratio of A to T is close to 1:1 and the ratio of G to C is close
to 1:1
⩥The "beads on a string" seen in interphase chromatin are __________.
Answer: nucleosomes
⩥The unwinding of DNA at the replication fork causes twisting and
strain in the DNA ahead of the fork, which is relieved by an enzyme
called___________.
Answer: topoisomerase
, ⩥The overall error rate in a completed DNA molecule is
approximately___________.
Answer: one error per 10,000,000,000 nucleotides
⩥One strand of a double-stranded DNA molecule has the base sequence
5'-ATAGGT-3'. The complementary base sequence on the other strand of
DNA will be 3'-__________-5'.
Answer: TATCCA
⩥During Griffith's experiments with Streptococcus pneumoniae in mice,
material from __________ bacteria transformed __________ bacteria.
Answer: heat-killed virulent; living nonvirulent
⩥Which of the following lists is in order from the entity with the
smallest genome to the entity with the largest genome?
Answer: Virus, bacteria, eukaryote
⩥In DNA, the two purines are __________, and the two pyrimidines are
__________.
Answer: adenine and guanine; cytosine and thymine
⩥Why were many of the early experiments on DNA carried out on
viruses and bacteria?
Answer: (All)
PAPER 2026 QUESTIONS WITH COMPLETE
SOLUTIONS COMPREHENSIVE STUDY
GUIDE GRADED A+
⩥What technique was most helpful to Watson and Crick in developing
their model for the structure of DNA?
Answer: X-ray crystallography
⩥A scientist assembles a bacteriophage with the protein coat of phage
T2 and the DNA of phage T4. If this composite phage were allowed to
infect a bacterium, the phages produced in the host cell would have
__________.
Answer: the protein and DNA of T4
⩥What is the major difference between bacterial chromosomes and
eukaryotic chromosomes?
Answer: Bacteria have a single circular chromosome, whereas
eukaryotes have several linear chromosomes.
⩥The role of DNA polymerases in DNA replication is to __________.
Answer: attach free nucleotides to the new DNA strand
,⩥Who is credited with discovering the structure of the DNA double
helix?
Answer: Watson and Crick
⩥The two strands of a DNA double helix are antiparallel. This means
that __________.
Answer: one strand runs in the 5' to 3' direction and the other runs in the
3' to 5' direction
⩥The experiments of Meselson and Stahl showed that DNA
Answer: replicates in a semiconservative fashion
⩥The rate of elongation of a DNA strand in prokaryotes is __________
the rate in eukaryotes.
Answer: much faster than
⩥DNA polymerase adds nucleotides to the __________ of the leading
strands and to the __________ of the lagging strands (Okazaki
fragments).
Answer: 3' end; 3' end
⩥Which of the following statements concerning the structure of DNA is
correct?
,Answer: Adenine forms two hydrogen bonds with thymine; guanine
forms three hydrogen bonds with cytosine.
⩥Once the DNA at the replication fork is unwound by helicases, what
prevents the two strands from coming back together to re-form a double
helix?
Answer: Single-strand binding proteins bind the unwound DNA and
prevent the double helix from re-forming.
⩥What enzyme joins Okazaki fragments?
Answer: DNA ligase
⩥Chargaff found that in DNA samples,___________.
Answer: the ratio of A to T is close to 1:1 and the ratio of G to C is close
to 1:1
⩥The "beads on a string" seen in interphase chromatin are __________.
Answer: nucleosomes
⩥The unwinding of DNA at the replication fork causes twisting and
strain in the DNA ahead of the fork, which is relieved by an enzyme
called___________.
Answer: topoisomerase
, ⩥The overall error rate in a completed DNA molecule is
approximately___________.
Answer: one error per 10,000,000,000 nucleotides
⩥One strand of a double-stranded DNA molecule has the base sequence
5'-ATAGGT-3'. The complementary base sequence on the other strand of
DNA will be 3'-__________-5'.
Answer: TATCCA
⩥During Griffith's experiments with Streptococcus pneumoniae in mice,
material from __________ bacteria transformed __________ bacteria.
Answer: heat-killed virulent; living nonvirulent
⩥Which of the following lists is in order from the entity with the
smallest genome to the entity with the largest genome?
Answer: Virus, bacteria, eukaryote
⩥In DNA, the two purines are __________, and the two pyrimidines are
__________.
Answer: adenine and guanine; cytosine and thymine
⩥Why were many of the early experiments on DNA carried out on
viruses and bacteria?
Answer: (All)
