A rII lysis mutation resulted from a point mutation is tested against numerous deletion mutations. A series of seven point mutations are mapped along the rIIA gene, and these are tested for their capability of producing wild-type recombinants when crossed with rII partial-deletion mutants. The results are listed in the table below, the “ + ”sign indicates the formation of wild-type recombinants and “ − ” indicates that wild-type recombinants are not formed. Using this data, show the stretch and end-points of each deletions as precisely as you can. Deletion Mutation Point mutation 12 19 21 27 34 37 46 B622 + + - + + + - CT48 - + + - - + + MB101 + + + + + - - VG14 + - + + + + + N220 + - - + - + + Introduction: The recombination frequency expresses the distance among genes. Least the recombination frequency, closer the genes are while greater recombination frequencies show that the gene distance is more. Point mutation is either deletion or addition of a nucleotide in a sequence of gene, which has the ability to return in their wild type phenotype by reversion. The deletion mutations are non-revertible mutations that lose the gene sequence, and the deleted sequence cannot be restored; hence, it cannot form wild-type recombinants. There are two types of mutants in T4 phages i.e. revertible and non-revertible mutants. If these mutants are crossed, these will either form wild-type recombinants or not.

Question

Want to see the full answer?

Answer 1

Question

Chapter 6, Problem 25P

Summary Introduction

To analyze:

A rII lysis mutation resulted from a point mutation is tested against numerous deletion mutations. A series of seven point mutations are mapped along the rIIA gene, and these are tested for their capability of producing wild-type recombinants when crossed with rII partial-deletion mutants. The results are listed in the table below, the “+”sign indicates the formation of wild-type recombinants and “−” indicates that wild-type recombinants are not formed.

Using this data, show the stretch and end-points of each deletions as precisely as you can.

Deletion
Mutation Point mutation

12 19 21 27 34 37 46

B622 + + - + + + -

CT48 - + + - - + +

MB101 + + + + + - -

VG14 + - + + + + +

N220 + - - + - + +

Introduction:

The recombination frequency expresses the distance among genes. Least the recombination frequency, closer the genes are while greater recombination frequencies show that the gene distance is more.

Point mutation is either deletion or addition of a nucleotide in a sequence of gene, which has the ability to return in their wild type phenotype by reversion. The deletion mutations are non-revertible mutations that lose the gene sequence, and the deleted sequence cannot be restored; hence, it cannot form wild-type recombinants.

There are two types of mutants in T4 phages i.e. revertible and non-revertible mutants. If these mutants are crossed, these will either form wild-type recombinants or not.

Expert Solution & Answer

Want to see the full answer?

Check out a sample textbook solution

See solution

Students have asked these similar questions

There are five substitution mutations in the dark-colored mutant Mc1r gene. Compare the DNA sequence of the light-colored wild-type Mc1r gene with the DNA sequence of the dark-colored mutant Mc1r gene. Indicate the locations of the five mutations by changing the font color to YELLOW for the five single DNA nucleotides that are mutated in the mutant Mc1r gene table. Using the information in the introduction, determine whether each of these mutations is a silent, missense, or nonsense mutation. Using the mutant Mc1r gene data, fill in the columns (including DNA, mRNA, and amino acid) in gene table 2 that contain a silent mutation with BLUE. Likewise, fill in the columns that contain a missense mutation with RED. Shade any columns that contain nonsense mutations with GREEN. Then Of the five mutations you identified in the mutant Mc1r gene, how many are: substitutions insertions deletions (Enter a number on each line.) 2. Of the five mutations…

People with a commonly occurring, wild type allele of PTC with two adjacent thymines at a particular site in the coding sequence are more prone to BCCs than people without this allele. How can this be explained (one sentence)? The "two adjacent thymines" allele of PTC causes a bigger increase in BCC risk for people xeroderma pigmentosum (XP), who lacks components of the nucleotide excision repair pathway, compared to people without XP. How can this be explained (one sentence)?

Four E. coli strains of genotype atb¯ are labeled 1, 2, 3, and 4. Four strains of genotype a¯b* are labeled 5, 6, 7, and 8. The two genotypes are mixed in all possible combinations and, after incubation, are plated to determine the frequency of a*b+ recombinants. The following results are obtained, where M=many recombinants, L=low number of recombinants, and 0=no recombinants: 1 3 4 M M 6. M M L M 8 L L Based on these results, assign a sex type to each strain. Answer Bank 2 F- Hfr F+ 3 4