Question 1

What is another name for Ac and Ds transposable elements,which emphasizes the effect on gene expression?

Accepted Answer

A)   Controsons
B)   Controlling elements
C)   Cosmids
D)   Controsons and controlling elements
E)   All of these B

Question 2

What type of transposon is an IS element?

Accepted Answer

A)   Cut and paste transposon
B)   Replicative transposon
C)   Retrovirus-like transposon
D)   Retrotransposon
E)   All of these A

Question 3

Ds elements that contain non-Ac DNA between their inverted terminal repeats are known as

Accepted Answer

A)   aberrant Ds elements.
B)   unusual Ds elements.
C)   double Ds elements.
D)   aberrant Ds elements and Unusual Ds elements.
E)   All of these A

Question 4

Explain how transposable elements are responsible for chromosomal breakage in the maize Ac/Ds system as shown by McClintock.

Accepted Answer

The answer of Explain how transposable elements are responsible for...

Question 5

In maize,the Ac factor is not associated with

Accepted Answer

A)   structural identity between different Ac elements.
B)   the activator of chromosomal breakage in regions containing aberrant Ds.
C)   Cis-acting in its ability to transpose Ds.
D)   inverted terminal and direct repeats.
E)   None of these

Question 6

Which of the following is a transposable element found in the human genome?

Accepted Answer

A)   LINES
B)   SINES
C)   Retrovirus-like elements
D)   All of these
E)   None of these

Question 7

Which transposon(s)is responsible for leaving delta-sequences in the chromosome after transposition?

Accepted Answer

A)   Tn5
B)   Ty elements
C)   Mariner
D)   P elements
E)   Retroposons

Question 8

Which of the following statements is not true about L1 elements?

Accepted Answer

A)   L1 is the only transposable element known to be active in humans.
B)   L1 is unique to humans alone.
C)   L1 elements are heterogeneous in size and maintained in single copy in the human genome.
D)   L1 not is a retroposon.
E)   None of these

Question 9

Which of the following enzymes is responsible for the synthesis of DNA from RNA which is then inserted into the new position in retrotransposition?

Accepted Answer

A)   Transformase
B)   Transposase
C)   Reverse transcriptase
D)   Ligase
E)   Helicase

Question 10

Which of the following describes the category of transposons in which transposition is accomplished by excising an element from its position in a chromosome and inserting it into another position?

Accepted Answer

A)   Cut and paste transposons
B)   Replicative transposons
C)   Retrotransposons
D)   Cut and paste transposons and replicative transposons
E)   All of these

Question 11

Which term is used to denote the syndrome produced from Drosophila crosses that gave rise to hybrids with an assortment of aberrant traits,including frequent mutation,chromosome breakage?

Accepted Answer

A)   Hybrid dysgenesis
B)   Hybrid displasia
C)   Hybrid polymorphism
D)   Hybrid dysgenesis and hybrid displasia
E)   All of these

Question 12

How do IS elements of E.coli contribute to horizontal gene transfer?

Accepted Answer

The answer of How do IS elements of E.coli contribute...

Question 13

How does the transposition of a Tn3 element occur?

Accepted Answer

The answer of How does the transposition of a Tn3...

Question 14

Which of the following pairs of DNA sequences could qualify as terminal repeats of IS elements? (read all sequences as 5' to 3')

Accepted Answer

A)   AATTCCGTG and AATTCCGTG
B)   TTCGTT and TTCGTT
C)   TGTGGCTTT and TTTCGGTGT
D)   TCTTGG and GGTTCT
E)   TATATA and ATATAT

Question 15

How does transposase act to catalyze transposition in IS elements?

Accepted Answer

The answer of How does transposase act to catalyze transposition...

Question 16

Which of the following are encoded by the genes in Tn3 elements?

Accepted Answer

A)   Transposase
B)   Beta lacatamase
C)   Resolvase
D)   Transposase and Beta lacatamase
E)   All of these

Question 17

Which category of transposons accomplishes transposition through a process that involves the insertion of copies of an element that were synthesized from the element's RNA?

Accepted Answer

A)   Cut and paste transposons
B)   Replicative transposons
C)   Retrotransposons
D)   Cut and paste transposons and Replicative transposons
E)   All of these

Question 18

Which type of transposon is not found in prokaryotes?

Accepted Answer

A)   IS elements
B)   Composite transposons
C)   Tn3
D)   Tac
E)   All of these are found in prokaryotes.

Question 19

Cut and paste transposition can occur in which of the following organisms?

Accepted Answer

A)   C. elegans
B)   E. coli
C)   S. aureus
D)   E. coli and S. aureus
E)   All of these

Question 20

If two transposons,in the same chromosome and in opposite orientation,pair and cross over,the segment between them will be

Accepted Answer

A)   inverted.
B)   deleted.
C)   inactive.
D)   unchanged.
E)   None of these

Exam 17: Transposable Genetics Elements