Suc- strains cannot utilize sucrose, trp- strains cannot synthesize tryptophan. In the generalized transduction of a suc-trp- strain of E. coli using bacteriophage derived from a suc+trp+ cell, what medium would select for suc+ and trp+? A) a minimal medium
B) a minimal medium + sucrose
C) a minimal medium + tryptophan
D) a minimal medium + sucrose + tryptophan
E) none of the above

B) a minimal medium + sucrose

Explanation:

Suc+ ⇒ can utilize sucrose, so you have to add sucrose to the medium.

Trp+ ⇒ can synthesize tryptophan, so it is not required to add tryptophan to the medium because the cell can produce it.

According to this, to select for suc+ trp+ you have to only add sucrose to the medium. Thus, it will only grow the cells that can utilize sucrose and can synthesize tryptophan.

Therefore, the correct option is: B) a minimal medium + sucrose

answer: ice crystals in air

the water from the water body or another source of water gets evaporated as water vapor as an effect of heat on water. these water vapor rises in the upper layers of the earth atmosphere under high atmospheric pressure. the atmospheric pressure of these water molecules starts to decrease due to the effect of cold air. the invisible water vapor condenses into visible water droplets and ice crystals.these ice crystals and water droplets being less denser than the surrounding air floats on air as clouds.