OPENSTAX MICROBIOLOGY CHAPTER 11
EXAM PREP: COMPLETE QUESTIONS AND
ANSWERS FOR THE FINAL PAPER 2026
◍ Gene expression. Ans: A process which includes both transcription
and translation, the synthesis of a specific protein with a sequence of
amino acids that is encoded in the gene.
◍ Central Dogma. Ans: The flow of genetic information from DNA
to RNA to protein
◍ Genotype. Ans: A cell's full collection of genes it contains.
◍ Phenotype. Ans: >>The set of observable characteristics that result
from the genotype
>>Phenotype is determined by the specific genes within a genotype
that are expressed under specific conditions. Although multiple cells
may have the same genotype, they may exhibit a wide range of
phenotypes resulting from differences in patterns of gene expression
in response to different environmental conditions.
◍ Three theories on DNA replication from parent to offspring. Ans:
Conservative
Semi-Concervative
Dispersive
, ◍ Conservative. Ans: The parental DNA strands remain together, and
the newly formed daughter strands are together
◍ Semi-conservative. Ans: Each of the two parental DNA strands act
as a template for new DNA to be synthesized; after replication, each
double-stranded DNA is composed of one old (parental) strand and
one newstrand.
◍ Dispersive. Ans: Both copies of DNA have double-stranded
segments of parental DNA and newly synthesized DNA interspersed.
◍ Meselson and Stahl study. Ans: Grew E. coli for several
generations and used a N isotope to demonstrate where new DNA was
found.
Study showed that DNA replication occurs in a semi-conservative
fashion
>>
◍ guanosine triphosphate deoxyribonucleotide (GTP). Ans: is
incorporated into a growing DNA strand by cleaving the two end
phosphate groups from the molecule and transferring the energy to the
sugar phosphate bond. The other three nucleotides form analogous
structures.
◍ Three main stages of DNA Replication. Ans: Initiation
Elongation
, Termination
◍ Initiation. Ans: DNA is made accessible to proteins and enzymes
required for replication
Origin-Specific sequence in DNA where replication begins
DNA helicase attaches at origin and begins to unwind dsDNA,
breaking hydrogen bonds and creating one or more y shaped
replication forks, an area where the dsDNA is separated and where
enzymes attach
Single-stranded binding proteins coat the
ssDNAnearthereplicationfork,preventing the ssDNA from reverting
back to the double helix
◍ ELongation. Ans: Primaseadds a short RNA sequence needed by
DNA polymerase III to being adding nucleotides
>>DNA polymerase III, starting at the primer, beings to add
nucleotides, needs a free 3' -OH group, so CAN ONLY ADD
NUCLEOTIDES IN THE 5' à3' direction.uSliding clamp protein
holds DNA polymerase III in place on the DNA template strand.
>>DNA is antiparallel, meaning that nucleotides must be added in two
different fashions, creating a leading strand and lagging strand.
◍ Leading strand. Ans: nucleotides are added continuously
◍ Lagging Strand. Ans: Nucleotides are added in short sequences
called OKAZAKI FRAGMENTS (must be linked together)
EXAM PREP: COMPLETE QUESTIONS AND
ANSWERS FOR THE FINAL PAPER 2026
◍ Gene expression. Ans: A process which includes both transcription
and translation, the synthesis of a specific protein with a sequence of
amino acids that is encoded in the gene.
◍ Central Dogma. Ans: The flow of genetic information from DNA
to RNA to protein
◍ Genotype. Ans: A cell's full collection of genes it contains.
◍ Phenotype. Ans: >>The set of observable characteristics that result
from the genotype
>>Phenotype is determined by the specific genes within a genotype
that are expressed under specific conditions. Although multiple cells
may have the same genotype, they may exhibit a wide range of
phenotypes resulting from differences in patterns of gene expression
in response to different environmental conditions.
◍ Three theories on DNA replication from parent to offspring. Ans:
Conservative
Semi-Concervative
Dispersive
, ◍ Conservative. Ans: The parental DNA strands remain together, and
the newly formed daughter strands are together
◍ Semi-conservative. Ans: Each of the two parental DNA strands act
as a template for new DNA to be synthesized; after replication, each
double-stranded DNA is composed of one old (parental) strand and
one newstrand.
◍ Dispersive. Ans: Both copies of DNA have double-stranded
segments of parental DNA and newly synthesized DNA interspersed.
◍ Meselson and Stahl study. Ans: Grew E. coli for several
generations and used a N isotope to demonstrate where new DNA was
found.
Study showed that DNA replication occurs in a semi-conservative
fashion
>>
◍ guanosine triphosphate deoxyribonucleotide (GTP). Ans: is
incorporated into a growing DNA strand by cleaving the two end
phosphate groups from the molecule and transferring the energy to the
sugar phosphate bond. The other three nucleotides form analogous
structures.
◍ Three main stages of DNA Replication. Ans: Initiation
Elongation
, Termination
◍ Initiation. Ans: DNA is made accessible to proteins and enzymes
required for replication
Origin-Specific sequence in DNA where replication begins
DNA helicase attaches at origin and begins to unwind dsDNA,
breaking hydrogen bonds and creating one or more y shaped
replication forks, an area where the dsDNA is separated and where
enzymes attach
Single-stranded binding proteins coat the
ssDNAnearthereplicationfork,preventing the ssDNA from reverting
back to the double helix
◍ ELongation. Ans: Primaseadds a short RNA sequence needed by
DNA polymerase III to being adding nucleotides
>>DNA polymerase III, starting at the primer, beings to add
nucleotides, needs a free 3' -OH group, so CAN ONLY ADD
NUCLEOTIDES IN THE 5' à3' direction.uSliding clamp protein
holds DNA polymerase III in place on the DNA template strand.
>>DNA is antiparallel, meaning that nucleotides must be added in two
different fashions, creating a leading strand and lagging strand.
◍ Leading strand. Ans: nucleotides are added continuously
◍ Lagging Strand. Ans: Nucleotides are added in short sequences
called OKAZAKI FRAGMENTS (must be linked together)
