In a diploid unicellular eukaryotic organism osmotic mutants prevent cells from
ID: 40528 • Letter: I
Question
In a diploid unicellular eukaryotic organism osmotic mutants prevent cells from growing on media with high levels of salt. The results shown in the table were obtained by crossing the mutants indicated. A +in the table indicates wild type phenotype in the progeny, a - in the table indicates that the crossing produced a mutant organism.
c. What is the minimum number of genes involved in allowing this organism to grow at high salt concentrations?
Mutant strains
A11
A52
A70
A71
B135
flm-2
L0
L5
M1
S1
A11
-
A52
+
-
A70
+
+
-
A71
+
+
-
-
B135
-
+
+
+
-
flm-2
+
+
+
+
+
-
L0
-
+
+
+
-
+
-
L5
+
+
-
-
+
+
+
-
M1
+
-
+
+
+
+
+
+
-
S1
+
+
+
+
+
+
+
+
+
-
Mutant strains
A11
A52
A70
A71
B135
flm-2
L0
L5
M1
S1
A11
-
A52
+
-
A70
+
+
-
A71
+
+
-
-
B135
-
+
+
+
-
flm-2
+
+
+
+
+
-
L0
-
+
+
+
-
+
-
L5
+
+
-
-
+
+
+
-
M1
+
-
+
+
+
+
+
+
-
S1
+
+
+
+
+
+
+
+
+
-
Explanation / Answer
The minimum number of genes involved in allowing the organism to grow even at high salt concentrations present in the media according to the list given is A 52 . as this has only one gene, yet it shows that it survived in high salt concentration media. media. osmotic mutants prevent a cell from growing in high salt concentrations, but in A52 just one gene was sufficient for it to survive. wild types have the capacity to survive high salt concentrations, whereas mutants do not. So when crossing the wild type with the mutants, the wild type is seen to show dominance over the mutants thus making A52 survive.
Minimum gene number that is required for its expression any organism increases with its complexity, the simpler the organism the simpler its genetic make up. this A52 being a unicellular organism requires just that.