Molecular : Replication, mutation and DNA Repair

An educational illustration depicting DNA replication and mutation processes, showing DNA strands, enzymes like DNA polymerase and ligase, and representations of mutations such as frameshift and missense, in an engaging and colorful style.

Explore DNA Dynamics: Replication, Mutation, and Repair

Test your knowledge on the fascinating processes of DNA replication, mutation, and repair! This quiz covers key concepts in molecular biology and is perfect for students, educators, and anyone interested in genetics.

Multiple choice format
Challenging questions on DNA mechanics
Learn about essential enzymes and their functions

42 Questions10 MinutesCreated by TeachingDNA101

Which of the three models of DNA replication proposed that the original double helix remained entirely intact throughout the process?

Which statement about bacterial DNA replication is correct?

DNA replication begins at several places along the chromosome

DNA replication begins at the origin and travels in both directions.

DNA replication begins at the origin and travels around the chromosome back to the origin

DNA replication begins at a GC rich region of the chromosome.

All of these are correct.

Why is an AT rich region part of the E. Coli oriC?

DnaA proteins bind to AT rich sites.

DnaC proteins bind to AT rich sites.

AT base pairs are more easily separated than GC base pairs

AT base pairs contain more hydrogen bonds than GC base pairs

Which enzyme produces the first piece of nucleic acid synthesized in E. coli DNA replication?

DNA polymerase (polIII)

DNA primase

DNA polymerase (polI)

DNA ligase

What is a key difference between DNA polIII and DNA ligase?

Only DNA polIII synthesizes phosphoester bonds

Only DNA ligase synthesizes phosphoester bonds.

DNA polIII can synthesize DNA from 3'-5'.

DNA ligase can use energy from ATP rather than nucleotides

What is the major difference between the lagging and leading strands?

On the leading strand, DNA synthesis occurs from 5' to 3', while DNA synthesis occurs from 3' to 5' on the lagging strand.

DNA polymerase is able to continuously add new nucleotides on the leading strand while it must keep 'starting over' on the lagging strand.

The lagging strand requires only a single primer while the leading strand requires many

Helicase opens the leading strand at a faster rate than the lagging strand.

What explanation for Okazaki fragments is the most accurate?

DNA polymerase is only able to synthesize 1000-2000 bonds before it falls off the strand.

DNA polymerase must stop to check its work every 1000-2000 nucleotides.

DNA polymerase requires a free 3' OH group to attach new nucleotides; primers are produced on the lagging strand every 1000-2000 nucleotides.

All of these are accurate statements.

None of these are accurate statements.

What is the major difference between T1 and T2 ?

A) T2 stops only counterclockwise-moving forks while T1 stops only clockwise-moving forks.

B) T1 work without need of ATP

C) T1 stops only counterclockwise-moving forks while T2 stops only clockwise-moving forks.

D) T2 work without need of ATP

B and C both are correct

Which of the following is a description of the proofreading function of DNA polymerase?

Which of the following is a key difference between eukaryotic and prokaryotic DNA replication?

Eukaryotic origins of replication contain a high % of AT base pairs and require protein binding for correct function.

In eukaryotes, DNA replication proceeds bidirectionally from the origin of replication.

Eukaryotes contain several different DNA polymerases.

Telomerase is required to replicate the ends of eukaryotic chromosomes

None of these: They could all also describe prokaryotic DNA replication

What aspect of DNA polymerase function necessitates use of telomerase in eukaryotes?

Telomerase activity in humans is generally restricted to the germ line, cancerous cells, and a few specific adult cell types. How would this be expected to impact humans?

Cancer cells can divide indefinitely.

Because there is a difference in number of divisions, sperm would be expected to have shorter telomeres than oocytes.

Rapidly dividing populations of cells have telomeres equal in size to slowly dividing populations of cells.

All of these.

None of these.

Mutations:

Are permanent changes in the DNA sequence or structure.

Produce allelic variation.

Are more likely to be harmful than beneficial

All of the above.

None of the above.

من أٝضل دكتور على وجه الكرة الأرضية ؟؟

A wild type allele:

Is the allele that is the most common in the population.

Is the allele with the highest level of functional protein

Is the most favorable allele in the population

All of the above.

None of the above

The mutation which causes sickle cell anemia in humans:

Provided the number of base pairs is a multiple of three, insertion of additional DNA in the coding region of a protein is unlikely to have a dramatic effect on protein function

True

False

Which of the following would be an example of a germline mutation?

Exposure to excessive UV radiation causes changes in the DNA of a skin cell, leading to basal cell carcinoma (skin cancer).

In a very early human embryo, a mistake in mitosis causes loss of a Y chromosome in one daughter cell. The resulting child is a fertile male who is chromosomally partially male (XY) and partially female with Turner's syndrome (XO).

A man with normal chromosomes has a hip X-ray without a protective shield. Ten months later, his wife gives birth to a child with a chromosomal deletion.

An embryo missing one copy of the third chromosome is miscarried very early in pregnancy.

Mitochondrial DNA polymerase does not have an error checking mechanism such as that of nuclear DNA polymerase. This would be expected to lead to a higher rate of which type of mutation in mitochondrial DNA?

مين أحسن طالب ٝي الدٝعة هههههه ؟

محمد اللصاصمه

MOHAMMAD ALASASSMEH

Mohammad allasassmeh

جميع الخيارات صحيح

In a haploid organism, lethal alleles would be expected to:

In which situation would you expect the mutation frequency to increase over time?

The deleterious effect of the mutation is balanced with the mutation rate

A lethal allele is created at a high mutation rate

A neutral allele is created at low mutation rate

All of the above

None of the above

Examples of environmental mutagens include:

DNA repair systems typically work in three major steps: detection of the error, removal of the abnormality, and replacement of the removed DNA.

True

False

Which of the following forms of DNA repair does NOT require DNA polymerase?

Why is alkyltransferase only able to be used once?

The protein is hydrolyzed in the process of repairing the DNa.

The protein is chemically changed by the addition of a methyl group

The protein becomes attached to the DNA strand

All of these.

None of these

How does recombinational repair differ from nucleotide excision repair (NER)?

Unlike NER, recombinational repair is unable to repair damage caused by thymine dimers.

NER replaces the thymine dimmer while recombinational repair leaves it in place.

NER requires DNA polymerase and ligase function, while recombinational repair does not.

NER involves nick translation, which recombinational repair does not.

Individuals with Cockayne syndrome are more likely to:

Have an increased rate of somatic mutation.

Have an increased rate of germ line mutation

Have a decreased rate of spontaneous mutation

Have a decreased rate of induced mutation

A new chemical pesticide developed for agricultural use was subjected to the Ames test. The rate of mutation seen in samples treated with the pesticide and liver extract was approximately half that of the samples treated with the liver extract alone; in samples treated with only pesticide, the mutation rate was about the same as that of untreated samples. Which of the following statements could you make about this pesticide?

The pesticide is modified by liver enzymes.

The pesticide is unlikely to be a mutagen

The pesticide may be protective against spontaneous mutation

All of the above

None of the above

If there is a malfunction in the θ subunit in polymerase III, what is the consequence of this defect ?

A α subunit defect that causes errors in the DNA replication process

A ε subunit defect that causes errors in the DNA replication process

A beta subunit defect that causes errors in the DNA replication process

All of above

In the stage of division, a genetic transit occurs, and during this process a mutation occurs, what kind of mutation?

If you know that the animal has a shelf life of 15 years, and a 10-year sample is taken and clones occur, when will the risk of mutation increase?

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Molecular : Replication, mutation and DNA Repair

Explore DNA Dynamics: Replication, Mutation, and Repair

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