Question

We have done a nutrient recovery experiment for Hec and Trp. Below are the growth results of plating nine colonies on plates containing different media compositions Minimal Media +Hec +Trp +Hec +Trp O 11000 ndicate which colonies have a loss of function mutation for the given genotypes. When filling in the blank, use the colony numbers in numerical order separated by commas only. No spaces. For example in the box enter: 1,2,6,10 Mutant Genotype Colony(ies) Hec- Trp- Hec-& Trp-

Answer 1

In this form of plating, we proceed sequentially from the left-most plate to the right-most one.
In the minimal media plate: 1,3,5,8 grow, which indicated that they had no mutant genotypes and were hence able to grow without any external aid in terms of added biological substances.
In the Hec⁺ media plate: 1,3,4,5,7,8 grow, which indicated that they had 4,7 as mutant genotypes that were unable to grow without any external aid in terms of added biological substances and hence required Hec ⁺ addition.
In the Trp⁺ media plate: 1,2,3,5,8,9 grow, which indicated that they had 2,9 as mutant genotypes that were unable to grow without any external aid in terms of added biological substances and hence required Trp ⁺ addition.
Finally, in the Hec⁺ & Trp⁺ media plate: All grow, which indicated that they had 6 as a double mutant genotype that was unable to grow without any external aid in terms of two added biological substances and hence required Hec⁺ & Trp⁺ addition.

Mutant Genotype:
Hec^- = 4,7
Trp- ​= 2,9
Hec^- & Trp^- = 6