End joining repairs a break in a coding region. What usually results?

• A perfect single-letter fix every time
• No change at all
• Small indels that often shift the reading frame

What decides the final edited sequence after the cutter breaks the DNA?

• The cell's repair pathway choice
• The colour of the marker
• The cutter's brand name

A glowing marker in edited cells proves the edit landed correctly.

Circle one:   True   False

You design a donor template. Which design raises template repair success?

• Short arms with the change far from centre
• Long matching arms with the change centred
• No matching arms at all

The same guide gives knockouts in resting cells but clean fixes in dividing cells with a donor. Why?

• Dividing cells run template repair in S and G2; resting cells mostly end join
• The guide sequence changes between cell types
• Resting cells lack all DNA

Two guides target the same site. One has a close lookalike elsewhere with mismatches far from the seed end. Which is riskier?

• Both are equally risky always
• The guide with the close lookalike
• Neither guide can ever cut off-target

To guarantee a clean knock-in, it is enough to deliver the cutter without any donor and hope the cell invents the fix.

Circle one:   True   False

A team claims zero off-targets after checking two sites with a weak assay. What is the flaw?

• Two sites are always enough with any assay
• Off-targets are impossible in principle
• A weak assay misses rare edits, so the safety claim outruns its evidence