For each item, indicate if it is demonstrating vertical gene transfer or horizontal gene transfer: E. coli cell undergoes binary fission to produce two daughter cells [Select] Yeast cell buds [Select] A plasmid is transferred from one bacterium to another [Select] A phage shuttles DNA captured from one host cell into another cell, where it is incorporated into the chromosomal DNA through homologous recombination [Select] A Streptococcus cell takes up small fragments of DNA released from other dving Streptococci in the environment and incorporates them into its chromosom ✓ [Select] Horizontal Vertical

When various strains of λ phage are seeded on a lawn of E. coli, they can form clear or turbid plaques.       (b) For mutant λ phages that can only form clear plaques, give two different types of mutation in the phage that can explain the clear plaque phenotype.

In E. coli, the gene bioD+ encodes an enzyme involved in biotin synthesis, and galK+ encodes an enzyme involved in galactose utilization. An E. coli strain that contained wild-type versions of both genes was infected with P1 phage, and then a P1 lysate was obtained. This lysate was used totransduce (infect) a strain that was bioD− and galK−. The cellswere plated on a medium containing galactose as the sole carbonsource for growth to select for transduction of the galK+ gene.This medium also was supplemented with biotin. The resultingcolonies were then restreaked on a medium that lacked biotin tosee if the bioD+ gene had been cotransduced. The following resultswere obtained:What information do you know based onthe question and your understanding of the topic?

In a P1 transduction experiment, the P1 lysate contains phages thatcarry pieces of the host chromosomal DNA, but the lysate also containsbroken pieces of chromosomal DNA. If a P1 lysate is used to transfer chromosomal DNA to another bacterium, how could you show experimentally that the recombinant bacterium has been transduced (i.e., has taken up a P1 phage with a piece of chromosomal DNA inside) versus transformed (i.e., has taken up a piece of chromosomal DNA that is not within a P1 phage coat)?

The {choose } options are transformation, conjugation, or transduction.

As mentioned in question 2 of More Genetic TIPS, origins oftransfer can be located in many different places on a bacterial chromosome,and their direction of transfer can be clockwise or counterclockwise.Let’s suppose a researcher conjugated six differentHfr strains that were thr + leu + tons str r azis lac + gal + pro + met +to an F − strain that was thr − leu − tonr str s azir lac − gal − pro −met −, and obtained the following results: Draw a map of the circular E. coli chromosome that shows thelocations and orientations of the origins of transfer in these six Hfrstrains.

Consider a hypothetical phage whose DNA replicates exclusively by rolling circle replication. A phage with radioactive DNA in both strands infects a bacterium and is allowed to replicate in a nonradioactive medium. Assume that only daughter DNA from the elongated branch ever gets packaged into progeny particles.    What fraction of the parental radioactivity will appear in the progeny phage? How many progeny phage will contain radioactive DNA? What is the fundamental difference between the initiation of θ replication and that of the rolling circle?

Most yeast grow suspended in culture, but some yeast grow as a film on the top of a liquid culture.  These are called flor yeast.   The following Southern blot is looking at the FLO11 gene that is thought to be involved in whether yeast are flor or not.  DNA was isolated from four different yeast strains.  Strains 1 and 3 are normal while strains 2 and 4 are flor (Fidalgo, 2006).  Based on the gene map and Southern results below, what aspect of FLO11 determines whether a strain will be flor or not?

If we were to examine a strain with the F plasmid inserted into the same site of the bacterial chromosome, but in the reverse orientation: a) What would the order of gene transfer be? Include all of the genetic markers including the amino acid and nucleic acid metabolism genes and streptomycin resistance. b) What cell types would be able to grow on the NA vs ECM media types? Be sure to include the genotypes of the cells that would grow. Remember that NA provides all nutrients the bacteria needs + no antibiotic and HCM = minimal medium + glucose + has streptomycin antibiotic c) Would we still be able to perform our mapping? Why or why not? (Hint: refer to part b above)

Describe the four phases of bacterial cell division. Where would horizontal gene transfer occur? Where would sporogenesis occur? If antibiotics generally target cells which are growing and dividing as fast as they can, when would antibiotics be most effective? If a culture had 4 cells to begin with and has a generation time of 60 minutes, how long would it take to get 1,048,576 cells?