DNA Quiz

Question 1

What enzyme adds nucleotides to the DNA strand?

Answer 1

DNA polymerase

Question 2

What enzyme unwinds DNA to form a replication fork?

Answer 2

Helicase

Question 3

Which strand shows discontinuous synthesis?

Answer 3

Lagging strand

Question 4

What enzyme replaces RNA with DNA to form double stranded DNA?

Answer 4

DNA polymerase

Question 5

What is the main difference between eukaryotic and prokaryotic replication?

Answer 5

Eukaryotic have more then one origin of replication and its a slower process than prokaryotic replication

Question 6

What is a codon?

Answer 6

Sequence of 3 nucleotides in mRNA

Question 7

What type of mutation is THE-CAT-SAT-MAT to HEC-ATS-ATM-ATX?

Answer 7

Frameshift mutation whether one nucleotide as been added or removed causing the grouping of nucleotides into codons shift

Question 8

mRNA most ressembles the template or coding strand?

Answer 8

Coding strand

Question 9

During transcription new NTPs are added at the 5’ or 3’ end?

Answer 9

3’ end since it binds with the hydroxyl group of the previous nucleotide

Question 10

What is added to the beginning and end of a mature transcript?

Answer 10

Beginning: 5’ cap
End: 3’ poly-A tail

Question 11

Which is coding exon or intron?

Answer 11

Exons

Question 12

What stops transcription?

Answer 12

Terminator sequence

Question 13

What stops translation?

Answer 13

A stop codon (UAA, UAG, UGA)

Question 14

What does interfering RNA do?

Answer 14

Regulates gene expression and protects cells from viral infections

Question 15

What enzyme cuts DNA to make sticky ends?

Answer 15

Restriction enzyme (endonuclease)

Question 16

How bacteria uses restriction enzymes?

Answer 16

As a defense mechanism to protect themselves from foreign DNA such as bacteriaphages

Question 17

What is the small circular replicating section of DNA in bacterium?

Answer 17

Plasmids

Question 18

How the lacZ gene used to detect recombinant DNA?

Answer 18

Reporter gene to detect recombinant DNA, lacZ encodes the enzyme beta galactosidase which breaks down a specific substrate
*Identify bacterial cells that contain recombinant DNA

Question 19

How is antibiotic resistance used to check whether bacteria have been transformed?

Answer 19

Cause it confers ampicillin and allow the cell to grow on ampicillin containing medium, since transformed bacteria are the only one that have plasmid and AmpR is within the plasmid

Question 20

What are the 3 main steps of PCR?

Answer 20

1-Denaturation
2-Annealing
3-DNA synthesis

Question 21

What is a DNA probe?

Answer 21

Single-stranded segment of DNA that is used to detect the presence of a specific complementary sequence of nucleotides in a sample of DNA or RNA

Question 22

What is the name of the positively charged proteins that organise chromatin structure?

Answer 22

Histones

Question 23

What is an operon?

Answer 23

Is a cluster of genes in prokaryotic cells that are transcribed together from a single promoter as a single mRNA molecule.

Question 24

What is a snRNP?

Answer 24

Small nuclear ribonucleoprotein is a complex of small RNA molecule and proteins that plays a critical role in the splicing of pre-mRNA in eukaryotic cells

Question 25

Gene imprinting = DNA methylation. What does it do?

Answer 25

Is a form of epigenetic regulation where the expression of certain genes depends on which parent the allele is inherited from. It is often associated with DNA methylation, which plays a key role in controlling the imprinting of these genes.