Direct gene transfer is the transfer of naked DNA into plant cells, but the presence of a rigid plant cell wall acts as a barrier to uptake. Thus, protoplasts are the favored target for direct gene transfer. Polyethylene glycol-mediated DNA uptake is a direct gene transfer method that uses the interaction between PEG, naked DNA, salts and the protoplast membrane to affect the transportation of DNA into the cytoplasm.
List-I | List II | ||
---|---|---|---|
A. | Phenol-formaldehyde resin | I | Glyptal |
B. | The copolymer of 1,3-butadiene and styrene | II | Novolac |
C. | Polyester of glycol and phthalic acid | III | Buna-S |
D. | Polyester of glycol and terephthalic acid | IV | Dacron |
Consider a water tank shown in the figure. It has one wall at \(x = L\) and can be taken to be very wide in the z direction. When filled with a liquid of surface tension \(S\) and density \( \rho \), the liquid surface makes angle \( \theta_0 \) (\( \theta_0 < < 1 \)) with the x-axis at \(x = L\). If \(y(x)\) is the height of the surface then the equation for \(y(x)\) is: (take \(g\) as the acceleration due to gravity)
A constant voltage of 50 V is maintained between the points A and B of the circuit shown in the figure. The current through the branch CD of the circuit is :
Neoprene is formed from chloroprene. It is prepared by free radical polymerisation. The monomer of neoprene is chloroprene. It is used for preparing gaskets, conveyor belts etc.