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) 
AB is a part of an electrical circuit (see figure). The potential difference \(V_A - V_B\), at the instant when current \(i = 2\) A and is increasing at a rate of 1 amp/second is:
In an oscillating spring mass system, a spring is connected to a box filled with sand. As the box oscillates, sand leaks slowly out of the box vertically so that the average frequency ω(t) and average amplitude A(t) of the system change with time t. Which one of the following options schematically depicts these changes correctly? 
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.