Select the procedure that will not saturate a thin-layer chromatography (tlc) developing chamber with developing solvent vapors.

The correct answer is adding ninhydrin to developing solvent.

Ninhydrinis used to detect (color) amino-acids, since amino acids are colourless compounds. So, after development, the TLC plate is sprayed with ninhydrin reagent and dried in an oven, at 105°C for about 5 minutes. It reacts with α- amino acids that results in purple coloured spots.  

the answer would be 2, if crossing over doesn’t occur 2 out of 4 of the daughter cells will have that allele.

hope this : )