The fungus Melampsora lini causes a disease known as flax rust. Different strains of M. lini cause varying degrees of the disease. Conversely, different strains of flax are resistant or sensitive to the various varieties of the fungus. The Bombay variety of flax is resistant to M. lini strain 22 but sensitive to M. lini strain 24. A strain of flax called 770B is just the opposite; it is resistant to strain 24 but sensitive to strain 22. When 770B was crossed to Bombay, all F1 individuals were resistant to both strain 22 and strain 24. When F1 individuals were self-fertilized, the following data were obtained: 43 resistant to strain 22 but sensitive to strain 24 9 sensitive to strain 22 and strain 24 32 sensitive to strain 22 but resistant to strain 24 110 resistant to strain 22 and strain 24 Explain the inheritance pattern for flax resistance and sensitivity to M. lini strains.

The fungus Melampsora lini causes a disease known as flax rust. Different strains of M. lini cause varying degrees of the disease. Conversely, different strains of flax are resistant or sensitive to the various varieties of the fungus. The Bombay variety of flax is resistant to M. lini strain 22 but sensitive to M. lini strain 24. A strain of flax called 770B is just the opposite; it is resistant to strain 24 but sensitive to strain 22. When 770B was crossed to Bombay, all F1 individuals were resistant to both strain 22 and strain 24. When F1 individuals were self-fertilized, the following data were obtained: 43 resistant to strain 22 but sensitive to strain 24 9 sensitive to strain 22 and strain 24 32 sensitive to strain 22 but resistant to strain 24 110 resistant to strain 22 and strain 24 Explain the inheritance pattern for flax resistance and sensitivity to M. lini strains.

Human Anatomy & Physiology (11th Edition)

11th Edition

ISBN:9780134580999

Author:Elaine N. Marieb, Katja N. Hoehn

Publisher:Elaine N. Marieb, Katja N. Hoehn

Chapter1: The Human Body: An Orientation

Section: Chapter Questions

Problem 1RQ: The correct sequence of levels forming the structural hierarchy is A. (a) organ, organ system,...

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You co-culture the following bacterial strains: an Hfr prototroph and an F- auxotroph for the genes mal, met, mtl, and xyl. You interrupt conjugation at various time points and place the mixtures on media plates lacking each of the nutrients. Based on the results shown in the image, what is the order of these four genes along the bacterial chromosome? Please explain!
Your TA gives you an Escherichia coli strain (AmreB) that carries a gene deletion in the mreB gene. As a result, the strain is not able to produce the MreB protein. Your task is to compare the morphology of actively growing AmreB cells to the parental wildtype strain (produces MreB). What difference in morphology will you likely observe? Would you expect the same in Staphylococcus aureus?
Prototrophy is often the phenotype selected to detecttransformants. Prototrophic cells are used for donorDNA extraction; then this DNA is cloned and the clonesare added to an auxotrophic recipient culture. Successfultransformants are identified by plating the recipientculture on minimal medium and looking for colonies.What experimental design would you use to make surethat a colony that you hope is a transformant is not, infact,a. a prototrophic cell that has entered the recipientculture as a contaminant?b. a revertant (mutation back to prototrophy by a secondmutation in the originally mutated gene) of theauxotrophic mutation?
A newly-identified relative of Staphylococcus is causing great concern at the Center for Disease Control. It has been observed that some strains of this new bacterial species are resistant to multiple antibiotics used in clinical settings. Thanks to your bacterial genetic prowess, you are hired as part of a research team whose mission is to characterize this new species. It appears that at least three different antibiotic resistance genes have integrated onto the bacterial chromosome: min+ = confers resistance to minocycline cep+ = confers resistance to cephalexin van+ = confers resistance to vancomycin The following table shows the results of your experiments. Transformation of the recipient cells was conducted, using the DNA of the donor cells. You next selected for recipient cells that had undergone transformation by plating the transformed cells on media containing minocycline. This enabled you to select for min+ cells. The min+ cells were then replica plated onto media…
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By conducting conjugation experiments between Hfr and recipientstrains, Wollman and Jacob mapped the order of many bacterialgenes. Throughout the course of their studies, they identified severaldifferent Hfr strains in which the F-factor DNA had been integratedat different places along the bacterial chromosome. A sample of theirexperimental results is shown in the following table:Explain how these results are consistent with the idea that thebacterial chromosome is circular?
Which of the following statements about conjugation is false? After a F- cell has conjugated with an F+ cell, both cells would be F+. Both Hfr and F+ bacteria have the ability to produce a sex pilus. In F+ × F- conjugation, none of the bacterial chromosome is transferred; only the F factor is. A Hfr strain usually transfers the entire bacterial chromosome to the recipient cell. F' × F- conjugation can produce a partially diploid bacterial cell.
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Agrobacterium tumefaciens is a bacterium that infects a wide range of broad-leaved plants. During infection, a plasmid called Ti is transferred into the plant cells, where that plasmid DNA is integrated into the plant’s genome. Some of the genes encoded by this plasmid are expressed by host cell machinery in the plant cell. These gene products produce plant hormones which stimulate cell division in the infected cells, causing the development of a plant tumor which provides an environment for that bacterium to grow. You are studying a novel isolate of A. tumefaciens and want to determine which of the genes on the Ti plasmid are expressed in the bacterium, and which are expressed in the plant. You start by sequencing the Ti plasmid. a) Considering the DNA sequence of Ti, describe two specific genetic features that would help you to differentiate whether a given gene is likely expressed in the plant or bacterium. b) You collect plant tumor tissue, containing both bacterial and plant…
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