Sijil Professional CRISPR

What is the primary function of the Cas9 protein in the CRISPR system?

• Acts as a guide RNA

• Cuts RNA molecules

• Binds to PAM sequences only

• Cleaves double-stranded DNA at specific target sites

In CRISPR-Cas9 genome editing, the specificity of the DNA target site is determined by:

• The Cas9 enzyme sequence

• The DNA polymerase activity

• The guide RNA sequence

• The PAM sequence alone

Which of the following is a requirement for Cas9 to initiate DNA cleavage?

• A DNA template strand

• High ATP concentration

• Presence of a Protospacer Adjacent Motif (PAM)

• RNA polymerase binding

What is the typical PAM sequence recognized by Streptococcus pyogenes Cas9?

• AATAAA

• TATA box

• NGG

• TTAA

One limitation of CRISPR-Cas9 technology is the potential for:

• Efficient transduction

• Accurate genome replication

• Off-target effects

• Increased recombination frequency

Which statement best describes homology-directed repair (HDR)?

• It is the default repair mechanism after Cas9-induced breaks.

• It requires a homologous DNA template to introduce precise edits.

• It functions only in prokaryotes.

• It randomly inserts nucleotides at the break site.

Which of the following tools allows single-base editing without introducing double-stranded breaks?

• TALEN

• Base editors (e.g., cytidine deaminase fused to dCas9)

• Standard CRISPR-Cas9

• Zinc finger nucleases

Prime editing differs from base editing in that it:

• Lacks any Cas9 component

• Requires an RNA-directed DNA polymerase but no guide RNA

• Can introduce insertions, deletions, and all base conversions

• Can only perform A-to-G or C-to-T edits

Which CRISPR system is most suitable for targeting and degrading RNA rather than DNA?

• Cas9

• Cas13

• Cas12a

• dCas9

In CRISPR applications for cancer immunotherapy, what is the main advantage of using CRISPR to engineer T cells?

• T cells become non-functional

• T cells can be redirected to target tumor-specific antigens

• T cells lose all receptors and become universal

• CRISPR prevents immune activation entirely