Pls help me asap! Neurospora of genotype a + c are crossed withNeurospora of genotype + b +. (Here, + isshorthand for the wild-type allele.) Thefollowing tetrads are obtained (note that thegenotype of the four spore pairs in an ascus arelisted, rather than listing all eight spores):a +с abс+ + c+ bc ab+a + ca +с abc a+с abc ab+ abc+ b ++ + ++ b ++ + ++ + c+ + ++ b ++ + + a b +a + ++ + c+ b +13714126253a. In how many cells has meiosis occurred toyield these data?b. Give the best genetic map to explain theseresults. Indicate all relevant geneticdistances, both between genes and betweeneach gene and the centromere.c. Diagram a meiosis that could give rise toone of the three tetrads in the class at the farright in the list.

A genus of Ascomycete fungi is called Neurospora. Neurospora species are molds with widely dispersed…

a. In how many cells has meiosis occurred to yield these data? b. Give the best genetic map to explain these results. Indicate all relevant genetic distances, both between genes and between each gene and the centromere. c. Diagram a meiosis that could give rise to one of the three tetrads in the class at the far right in the list.

a. In how many cells has meiosis occurred to yield these data? b. Give the best genetic map to explain these results. Indicate all relevant genetic distances, both between genes and between each gene and the centromere. c. Diagram a meiosis that could give rise to one of the three tetrads in the class at the far right in the list.

Biology (MindTap Course List)

11th Edition

ISBN:9781337392938

Author:Eldra Solomon, Charles Martin, Diana W. Martin, Linda R. Berg

Publisher:Eldra Solomon, Charles Martin, Diana W. Martin, Linda R. Berg

Chapter11: The Basic Principles Of Heredity

Section: Chapter Questions

Problem 11TYU: Individuals of genotype AaBb were mated to individuals of genotype aabb. One thousand offspring were...

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From the fungal cross arg-6 ⋅ al-2 × arg-6+ ⋅ al-2+, whatwill the spore genotypes be in unordered tetrads thatare (a) parental ditypes? (b) tetratypes? (c) nonparental ditypes?
The a, b, and c loci are all on different chromosomesin yeast. When a b+ yeast were crossed to a+ b yeastand the resultant tetrads analyzed, it was found thatthe number of nonparental ditype tetrads was equal tothe number of parental ditypes, but there were no tetratype asci at all. On the other hand, many tetratypeasci were seen in the tetrads formed after a c+ wascrossed with a+ c, and after b c+ was crossed withb+ c. Explain these results.
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On Neurospora chromosome 4, the leu3 gene is just to theleft of the centromere and always segregates at the firstdivision, whereas the cys2 gene is to the right of the centromere and shows a second-division segregation frequency of 16 percent. In a cross between a leu3 strain anda cys2 strain, calculate the predicted frequencies of thefollowing seven classes of linear tetrads where l = leu3 andc = cys2. (Ignore double and other multiple crossovers.)
Homozygous wild-type male mice (AA BB CC) were crossed with triplemutant female mice (aa bb cc), forming an F1 generation with the followinggenotype (Aa Bb Cc). The F1 males were crossed with triple mutantfemales, forming the following F2 phenotypes”“a B c” 3“A b C” 3“a b c” 8“A B c” 5“a b C” 5“A B C” 8“a B C” 6“A b c” 6 44 Determine the sequence of the genes
Two crosses were made in Neurospora involvingthe mating type locus and either the ad or p genes.In both cases, the mating type locus (A or a) was oneof the loci whose segregation was scored. One crosswas ad A × ad+ a (cross i), and the other was p A × p+ a(cross ii). From cross i, 10 parental ditype, 9 nonparental ditype, and 1 tetratype asci were seen.From cross ii, the results were 24 parental ditype,3 nonparental ditype, and 27 tetratype asci.a. What are the linkage relationships between themating type locus and the other two loci?b. Although these two crosses were performed inNeurospora, you cannot use the data given tocalculate centromere-to-gene distances for anyof these genes. Why not?
The life cycle of the haploid fungus Ascobolus is similar tothat of Neurospora. A mutational treatment producedtwo mutant strains, 1 and 2, both of which when crossedwith wild type gave unordered tetrads, all of the followingtype (fawn is a light brown color; normally, crosses produce all black ascospores):spore pair 1 black spore pair 3 fawnspore pair 2 black spore pair 4 fawna. What does this result show? Explain.The two mutant strains were crossed. Most of the unordered tetrads were of the following type:spore pair 1 fawn spore pair 3 fawnspore pair 2 fawn spore pair 4 fawnb. What does this result suggest? Explain.When large numbers of unordered tetrads were screenedunder the microscope, some rare ones that containedblack spores were found. Four cases are shown here:Case A Case B Case C Case Dspore pair 1 black black black blackspore pair 2 black fawn black abortspore pair 3 fawn fawn abort fawnspore pair 4 fawn fawn abort fawn(Note: Ascospores with extra genetic material…
Based on your knowledge of genetics, how would you determine whether kanamycin or BASTA-resistant T2 seedlings are homo- or hemizygous for Bar or NPTII?
One yeast strain carries the alleles lys+ and arg+, whereas another strain has lys-3 and arg-2. The two strains were crossed toeach other, and an ascus obtained from this cross has four spores with the following genotypes: lys+ arg+, lys+ arg-2, lys-3arg+, and lys-3 arg 2. This ascus has a. a parental ditype.b. a tetratype.c. a nonparental ditype.d. either a tetratype or a nonparental ditype.
In Neurospora, the mutant stp exhibits erratic stop-andstart growth. The mutant site is known to be in the mtDNA. If an stp strain is used as the female parent in a crosswith a normal strain acting as the male, what type ofprogeny can be expected? What about the progeny fromthe reciprocal cross?
From a cross between e+ f+ g+ and e− f − g− strains ofNeurospora, recombination between these linkedgenes resulted in a few octads containing the followingordered set of spores:e+ f+ g+e+ f+ g+e+ f − g+e+ f − g+e− f − g−e− f − g−e− f − g−e− f − g−a. Where was recombination initiated?b. Did crossing-over occur between genes e and g?Explain.c. Why do you end up with 2 f+ : 6 f − but 4 e+: 4 e−and 4g+: 4g−?d. Could you characterize these unusual octads as MIor MII for any of the three genes involved?Explain.
From a series of two-point crosses, the following mapdistances were obtained for the syntenic genes A, B,C, and D in peas:B ↔ C 23 m.u.A ↔ C 15 m.u.C ↔ D 14 m.u.A ↔ B 12 m.u.B ↔ D 11 m.u.A ↔ D 1 m.u.Chi-square analysis cannot reject the null hypothesis of no linkage for gene E with any of theother four genes.a. Draw a cross scheme that would allow you todetermine the B ↔ C map distance.b. Diagram the best genetic map that can be assembled from this data set.c. Explain any inconsistencies or unknown features inyour map.d. What additional experiments would allow you toresolve these inconsistencies or ambiguities?