Module 2 MCQ Flashcards
Which statement about the proteins involved in DNA replication is NOT correct?
(A) DNA polymerase III progressively adds new nucleotides.
(B) The primase enzyme provides a starting point by synthesising an RNA primer.
(C) The single-stranded DNA binding proteins unwind the DNA helix.
(D) Topoisomerase releases the tension generated by DNA helicase.
(C)
The single-stranded DNA binding proteins unwind the DNA helix.
During DNA replication the:
(A) DNA polymerase III binds to the TATA box.
(B) helicase enzyme unwinds the two strands of DNA.
(C) primase enzyme synthesises a DNA primer.
(D) leading strand is synthesised as Okazaki fragments.
(B)
Helicase enzyme unwinds the two strands of DNA.
Which statement about correcting DNA errors is NOT correct?
(A) DNA polymerase III can correct errors during the replication process.
(B) Errors that arise after DNA replication are removed by an endonuclease.
(C) DNA polymerase III uses its exonuclease activity to remove incorrect bases.
(D) DNA helicase is required to correct errors that arise after DNA replication.
(D)
DNA helicase is required to correct errors that arise after DNA replication.
The polymerase chain reaction amplifies DNA:
Exponentially.
During meiosis, homologous pairs of chromosomes are held together by:
Chiasmata.
How many chromatids in total would you expect to see in a human cell at Metaphase 1 of
meiosis?
92
The structures that move to the spindle poles at anaphase of the first division of meiosis will
normally differ from those that move to the poles at anaphase of the second division of
meiosis with respect to:
- Chromatid number
- Gene copy number.
- The ratio of maternal to paternal genes.
Drosophila melanogaster males do not undergo meiotic crossing-over. D. melanogaster has a diploid chromosome number of 8.
How many different kinds of gametes can be produced by a
male D. melanogaster?
16
Chromosomal non-disjunction is a major cause of:
Turner syndrome.
Tortoiseshell (and calico) cats have an irregular fur pattern of ginger patches and black patches due to X inactivation. Most tortoiseshell cats are chromosomally:
Normal females.
Which of the following statements about the transcription of DNA is NOT correct?
(A) RNA polymerase begins transcribing DNA from a short RNA primer.
(B) The strand of DNA that is transcribed is known as the “template strand”.
(C) Eukaryotic transcripts may be modified after transcription.
(D)The RNA transcript is produced in the 5’ to 3’ direction.
(A)
RNA polymerase begins transcribing DNA from a short RNA primer.
- B
Below is a short section of DNA.
5ʹ GCAATC 3ʹ
3ʹ CGTTAG 5ʹ
What is a product of the transcription of this piece of DNA?
3ʹ CGUUAG 5ʹ
Which of the following statements about translation is NOT correct?
(A) Translation requires an input of energy.
(B) Translation requires more than one class of RNA.
(C)Translation most commonly begins at an AUG codon.
(D)Translation termination requires a specific tRNA.
(D)
Translation termination requires a specific tRNA.
The three bases on the tRNA molecule that are complementary to the triplet of mRNA are referred to as:
An anticodon.
In a case of incomplete dominance, a monohybrid cross will produce the following ratio of phenotypes in the progeny:
1:2:1
The height of spike weed is a result of polygenic inheritance involving three genes, for which “dominant” alleles can each contribute an additional 5cm to the base height (10cm) of the plant. The tallest plant (AABBCC) can reach a height of 40cm. If a tall plant (AABBCC) is crossed with a base-height plant (aabbcc),
What is the expected height of the F1 plants?
25cm
Linkage of two genes is inferred when a dihybrid cross yields:
Significantly fewer recombinant phenotypes than expected under Mendel’s second law.
Colour blindness is an X-linked recessive disorder. If an affected male mates with a carrier female,
What will the phenotypes of their offspring most likely be?
Half of all offspring will be affected.
If 1 in 10,000 children is born with an autosomal recessive disease,
What percentage of the
population are expected to be carriers for this disease?
1.98%
Genetic drift is expected to occur rapidly as a result of:
- a population bottleneck.
- a founder effect.
- small population size.
