Molecular biology exam quiz and
answers graded A+
what percent of the human genome does not encode for any protein?
a. 98%
b. 22%
c. 2%
d. 50% - ANS✅✅a. 98%
which type of cell division is responsible for recombination?
a. cytokinesis
b. meiosis
c. fertilization
d. mitosis - ANS✅✅b. meiosis
which of these structures within the DNA molecules cause it to have a negative charge?
a. the deoxyribose sugar
b. the phosphate groups
c. the nitrogenous bases
d. the hydrogen bonds - ANS✅✅b. the phosphate groups
the structures that hold together sister chromatids are called
a. chromosomes
b. spindle fibers
c. telomeres
d. centromeres - ANS✅✅d. centromeres
in crossing of a homozygous recessive with a heterozygote, what is the chance of getting an offspring
with the homozygous phenotype?
a. 50%
b. 75%
, c. 0%
d. 25% - ANS✅✅a. 50%
during translation, which site in the ribosome allows for tRNA molecules to enter the complex?
a. R site or ribosomal site
b. A site or amino-acyl site
c. P site or peptidyl site
d. E site or exit site - ANS✅✅b. A site or amino-acyl site
why does DNA synthesis only proceed in the 5' to 3' direction?
a. because the chromosomes are always aligned in the 5' to 3' direction in the nucleus
b. because that is the direction in which two strand of DNA unzip
c. because DNA polymerases can only add nucleotides to the 3' end of the sugar molecule of a
polynucleotide strand
d. because that is the only direction that the RNA polymerase can be oriented - ANS✅✅c. because
DNA polymerases can only add nucleotides to the 3' end of the sugar molecule of a polynucleotide
strand
what is the role of the promoter region in the regulation of gene expression?
a. terminates protein synthesis
b. allows splicing and recombination of genetic components
c. recruits RNA polymerase and transcription factors to DNA
d. allows the binding of ribosomes - ANS✅✅c. recruits RNA polymerase and transcription factors
to DNA
a point mutation that changes a codon specifying an amino acid into a stop codon is called a
a. missense mutation
b. nonsense mutation
c. silent mutation
d.frameshift mutation - ANS✅✅b. nonsense mutation
which gene mutation will not change the amino acid sequence of the polypeptide created during
translation of this gene?
answers graded A+
what percent of the human genome does not encode for any protein?
a. 98%
b. 22%
c. 2%
d. 50% - ANS✅✅a. 98%
which type of cell division is responsible for recombination?
a. cytokinesis
b. meiosis
c. fertilization
d. mitosis - ANS✅✅b. meiosis
which of these structures within the DNA molecules cause it to have a negative charge?
a. the deoxyribose sugar
b. the phosphate groups
c. the nitrogenous bases
d. the hydrogen bonds - ANS✅✅b. the phosphate groups
the structures that hold together sister chromatids are called
a. chromosomes
b. spindle fibers
c. telomeres
d. centromeres - ANS✅✅d. centromeres
in crossing of a homozygous recessive with a heterozygote, what is the chance of getting an offspring
with the homozygous phenotype?
a. 50%
b. 75%
, c. 0%
d. 25% - ANS✅✅a. 50%
during translation, which site in the ribosome allows for tRNA molecules to enter the complex?
a. R site or ribosomal site
b. A site or amino-acyl site
c. P site or peptidyl site
d. E site or exit site - ANS✅✅b. A site or amino-acyl site
why does DNA synthesis only proceed in the 5' to 3' direction?
a. because the chromosomes are always aligned in the 5' to 3' direction in the nucleus
b. because that is the direction in which two strand of DNA unzip
c. because DNA polymerases can only add nucleotides to the 3' end of the sugar molecule of a
polynucleotide strand
d. because that is the only direction that the RNA polymerase can be oriented - ANS✅✅c. because
DNA polymerases can only add nucleotides to the 3' end of the sugar molecule of a polynucleotide
strand
what is the role of the promoter region in the regulation of gene expression?
a. terminates protein synthesis
b. allows splicing and recombination of genetic components
c. recruits RNA polymerase and transcription factors to DNA
d. allows the binding of ribosomes - ANS✅✅c. recruits RNA polymerase and transcription factors
to DNA
a point mutation that changes a codon specifying an amino acid into a stop codon is called a
a. missense mutation
b. nonsense mutation
c. silent mutation
d.frameshift mutation - ANS✅✅b. nonsense mutation
which gene mutation will not change the amino acid sequence of the polypeptide created during
translation of this gene?
