Agrobacterium tumefaciens Transformation Quiz

Which of the following best explains the process of disarming the Ti plasmid in Agrobacterium tumefaciens?

• Removing virulence genes to enhance T-DNA transfer efficiency

• Deleting genes responsible for opine synthesis

• Replacing tumor-inducing genes with the gene of interest while retaining virulence genes

• Suppressing the expression of chromosomal genes involved in plant cell infection

In Agrobacterium tumefaciens-mediated transformation, what is the role of the T-DNA border sequences?

• Facilitate integration of T-DNA into the bacterial genome

• Mark the region of DNA to be excised and transferred to the plant cell

• Enable the translation of plant-derived proteins

• Promote replication of the Ti plasmid within the plant cell nucleus

Which of the following is a significant advantage of using Agrobacterium tumefaciens for plant transformation?

• It allows targeted integration of the transgene into specific loci.

• It can infect a wide range of monocot and dicot plants.

• It facilitates stable integration of the transgene into the plant genome.

• It eliminates the need for tissue culture in plant transformation.

In Agrobacterium-mediated transformation, what triggers the activation of the virulence (vir) genes on the Ti plasmid?

• The presence of plant phenolic compounds such as acetosyringone

• The insertion of the T-DNA into the plant genome

• Direct contact between Agrobacterium and the plant cell membrane

• The synthesis of opines by the plant cells

Which factor ensures the precise excision of T-DNA from the Ti plasmid before its transfer into the plant cell?

After the T-DNA enters the plant cell, what ensures its transport to the nucleus for integration?

• The presence of plant nuclear localization signals in VirD2

• The replication of T-DNA within the plant cytoplasm

• Active transport by the Type IV secretion system in the plant cell

• Homologous recombination facilitated by bacterial proteins

Why is Agrobacterium-mediated transformation considered a natural genetic engineering tool?

• Because it requires minimal human intervention during T-DNA transfer

• It inherently integrates genes into specific plant chromosomal loci.

• It evolved to naturally transfer genes from bacteria to plants for its survival.

• It enables gene transfer without the need for selectable markers.

What modification ensures that Agrobacterium remains non-pathogenic while still capable of gene transfer?

• Deletion of vir genes to eliminate the infection process

• Removal of T-DNA genes responsible for tumor formation

• Substitution of bacterial promoters with plant-specific promoters

• Integration of antibiotic resistance genes into the Ti plasmid

A researcher introduces a foreign gene into the T-DNA region but observes no plant transformation. What could be a plausible explanation?

• The T-DNA borders were accidentally deleted.

• The gene of interest was not transcribed in the plant cells.

• The vir genes were silenced in the Agrobacterium strain.

• The Ti plasmid lacked an origin of replication.

How does the VirD2 protein assist in the transfer of T-DNA from Agrobacterium to the plant genome?

• By forming a channel for T-DNA transport across the plant cell membrane

• By binding to T-DNA and guiding it to the plant nucleus for integration