You are using nitrosoguanidine to “revert” mutant nic-2(nicotinamide-requiring) alleles in Neurospora.You treat cells, plate them on a medium without nicotinamide, and look for prototrophic colonies. You obtainthe following results for two mutant alleles. Explainthese results at the molecular level, and indicate how youwould test your hypotheses.a. With nic-2 allele 1, you obtain no prototrophs at all.b. With nic-2 allele 2, you obtain three prototrophiccolonies A, B, and C, and you cross each separately with awild-type strain. From the cross prototroph A × wildtype, you obtain 100 progeny, all of which are prototrophic.From the cross prototroph B × wild type, you obtain100 progeny, of which 78 are prototrophic and 22 arenicotinamide requiring. From the cross prototrophC × wild type, you obtain 1000 progeny, of which 996 areprototrophic and 4 are nicotinamide requiring.
Gene Interactions
When the expression of a single trait is influenced by two or more different non-allelic genes, it is termed as genetic interaction. According to Mendel's law of inheritance, each gene functions in its own way and does not depend on the function of another gene, i.e., a single gene controls each of seven characteristics considered, but the complex contribution of many different genes determine many traits of an organism.
Gene Expression
Gene expression is a process by which the instructions present in deoxyribonucleic acid (DNA) are converted into useful molecules such as proteins, and functional messenger ribonucleic (mRNA) molecules in the case of non-protein-coding genes.
You are using nitrosoguanidine to “revert” mutant nic-2
(nicotinamide-requiring) alleles in Neurospora.
You treat cells, plate them on a medium without nicotinamide, and look for prototrophic colonies. You obtain
the following results for two mutant alleles. Explain
these results at the molecular level, and indicate how you
would test your hypotheses.
a. With nic-2 allele 1, you obtain no prototrophs at all.
b. With nic-2 allele 2, you obtain three prototrophic
colonies A, B, and C, and you cross each separately with a
wild-type strain. From the cross prototroph A × wild
type, you obtain 100 progeny, all of which are prototrophic.
From the cross prototroph B × wild type, you obtain
100 progeny, of which 78 are prototrophic and 22 are
nicotinamide requiring. From the cross prototroph
C × wild type, you obtain 1000 progeny, of which 996 are
prototrophic and 4 are nicotinamide requiring.
Trending now
This is a popular solution!
Step by step
Solved in 2 steps
