Observe the given figure and name the step used in Recombinant DNA Technology.
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → Spooling
The figure shows the step of isolating DNA. After the cell walls, RNA and proteins are removed, chilled ethanol is added and the purified DNA comes out as a mass of fine threads.
Option (4) Spooling — Correct. The DNA threads are wound round a glass rod and lifted out. This is spooling.
NCERT Extract:
Isolation of the Genetic Material (DNA) – “… You know that genes are located on long molecules of DNA interwined with proteins such as histones. The RNA can be removed by treatment with ribonuclease whereas proteins can be removed by treatment with protease. Other molecules can be removed by appropriate treatments and purified DNA ultimately precipitates out after the addition of chilled ethanol. This can be seen as collection of fine threads in the suspension (Figure 9.5).”
