Question

why is a virus a good vector to deliver a new gene (like non - sickling beta - globin) into blood stem cells?
they are infectious agents that cause mutations.
they naturally inject genetic material into host cells as part of their normal life cycle.
they kill off existing stem cells to make room for the genetically engineered replacement cells.
sick cells accept foreign dna more readily than healthy cells.

Explanation:

Viruses have a natural ability to deliver genetic material into host cells during their life cycle. This property makes them useful vectors for gene delivery. Option A is incorrect as viruses are not used because they cause mutations. Option C is wrong as viruses are not used to kill stem cells. Option D is not a reason related to viruses being good vectors.

Answer:

B. They naturally inject genetic material into host cells as part of their normal life cycle.