Which of following is true in order to force bacteria to take up the plasmid?

Both A and B.

a-This is done by treating them with a specific concentration of a divalent cation.

b-By placing them briefly at 42⁰C (heat shock), and then putting them back on ice.

c-Both A and B.

d-Insertional inactivation.

The correct option is:

Both A and B.

To force bacteria to take up the plasmid (a process known as bacterial transformation), two key steps are involved:

A. Treating them with a specific concentration of a divalent cation: Bacterial cells are made "competent" to take up DNA by treating them with a divalent cation, such as calcium. This treatment increases the efficiency with which the plasmid DNA can enter the bacterium through pores in its cell wall.

B. Heat shock: After treating the bacteria with the plasmid DNA, they are briefly subjected to a temperature increase, typically around 42°C (heat shock). This heat shock increases the permeability of the bacterial cell membrane, allowing for enhanced uptake of the plasmid DNA.

By combining these two steps, the bacterial cells become competent and can efficiently take up the recombinant DNA, leading to the introduction of the plasmid into the bacteria. The inserted DNA can then replicate within the host bacteria, making them genetically transformed or "recombinant" cells.