Practice question

Floxed allele describes engineered genomic locus where essential region is flanked by loxP sequences, derived from phrase flanked by loxP. Construction inserts 34 base pair loxP sites into introns bracketing target exon via homologous recombination in embryonic stem cells, without disrupting transcription. Without Cre, floxed gene expresses normally. Upon crossing to Cre driver, recombination deletes floxed segment in desired tissue. Floxed terminology distinguishes conditional ready allele from constitutive knockout, enabling temporal control, lineage tracing and rescue experiments in mouse genetics.