Question

multiple choice question

in simple transposition, ______.

a transposable element is transcribed into rna and this rna is used as a template to produce dna that is inserted into a new site
a transposable element remains at its original location while a copy is inserted at another site
a transposable element is removed from its original site and inserted at another location
transposable elements decrease in number within the cell

Explanation:

Define simple transposition mechanism

Simple transposition, also known as conservative or "cut-and-paste" transposition, involves the physical excision of the transposable element from its original genomic site by transposase.

Analyze the fate of the element

The excised double-stranded DNA element is then integrated directly into a new target site, meaning it does not leave a copy behind at the donor locus.

Evaluate the given options

• Option 1 describes retrotransposition (copy-and-paste via an RNA intermediate).
• Option 2 describes replicative transposition (copy-and-paste where the original remains).
• Option 3 correctly describes simple transposition (cut-and-paste).
• Option 4 is incorrect as transposition generally maintains or increases element numbers, rather than decreasing them.

Answer:

• (A) a transposable element is transcribed into RNA and this RNA is used as a template to produce DNA that is inserted into a new site
• (B) a transposable element remains at its original location while a copy is inserted at another site
• (C) a transposable element is removed from its original site and inserted at another location (Correct answer)
• (D) transposable elements decrease in number within the cell