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 ooo ooo O O O O O O OOO Indicate 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) Нес- Tro- Hec- & Trp-

Answer 1

Answer :

Mutant genotype	Colony(ies)
Hec-	6
Trp-	3, 8
Her-Trp-	1, 4

Explanation:

• wild type will be able to grow on minimal media, indicated by 2, 5, 7,9. mutants for Hec will grow only when Hec is added to minimal media, this is the media, and on +Hec 2, 5, 6, 7, 9 can grow. But since 2, 5, 7, 9 are wild types, thus '6' is the mutant colony for Hec. They are Hec- • Mutants for trip will grow when trp is added to minimal media, + Trp. Colonies that grow in + Top are 2,3,5,7,8,9. since, 2,5,7,9 are wild - types, the remaining colonies i-l. 3 and 8 arte mutant for top and they are denoted at tap-.. • mutants for both Hec and tup will grow in a media where both these are added, ie thee , ttup media. All colonies (1 to 9) grows on such media, but Hec- and Trip will be the ones left after excluding wild types, Hec-, and Tep- , i.e. we need to exclude 2, 3, 5, 6, 7, 8, 9 Hence, Hec- trp- colonies are 1,4.

Minimal Media +Hec +Trp +Hec +Trp Hec- Trp- Hec-Trp-