In rice, plants homozygous for the recessive allele sd1 are relatively short in stature; heterozygotes are of normal height. Plants carrying one copy of a dominant allele, Xa4 (corresponding to a second gene located on a different chromosome), are resistant to bacterial blight. Note that both the sd1 and Xa4 alleles would be considered "mutant" alleles in this scenario. A farmer obtained two pureline plants (one is homozygous for the sd1 mutant and the other is homozygous for the Xa4 mutant) and crossed them. Assume both pureline plants have identical alleles at all other loci, and no other mutant alleles are present in these two plants, which of these statements is correct? O All the progeny will be susceptible to bacterial blight and will be short. O When a progeny plant from the cross goes through meiosis, gametes will either contain sd1 or Xa4 alleles, but never both. O When a progeny plant from the cross goes through meiosis, four possible types of gametes that may form, and the ratio of gametes will be 9:3:3:1. O All the progeny will be resistant to bacterial blight and of normal height

In rice, plants homozygous for the recessive allele sd1 are relatively short in stature; heterozygotes are of normal height. Plants carrying one copy of a dominant allele, Xa4 (corresponding to a second gene located on a different chromosome), are resistant to bacterial blight. Note that both the sd1 and Xa4 alleles would be considered "mutant" alleles in this scenario. A farmer obtained two pureline plants (one is homozygous for the sd1 mutant and the other is homozygous for the Xa4 mutant) and crossed them. Assume both pureline plants have identical alleles at all other loci, and no other mutant alleles are present in these two plants, which of these statements is correct? O All the progeny will be susceptible to bacterial blight and will be short. O When a progeny plant from the cross goes through meiosis, gametes will either contain sd1 or Xa4 alleles, but never both. O When a progeny plant from the cross goes through meiosis, four possible types of gametes that may form, and the ratio of gametes will be 9:3:3:1. O All the progeny will be resistant to bacterial blight and of normal height

Human Heredity: Principles and Issues (MindTap Course List)

11th Edition

ISBN:9781305251052

Author:Michael Cummings

Publisher:Michael Cummings

Chapter11: Genome Alterations: Mutation And Epigenetics

Section: Chapter Questions

Problem 16QP: Familial retinoblastoma, a rare autosomal dominant defect, arose in a large family that had no prior...

See similar textbooks

Similar questions

A yeast geneticist irradiates haploid cells of a strain that is an adenine-requiring auxotrophic mutant, caused by mutation of the gene ade1. Millions of the irradiated cells are plated on minimal medium, and a small number of cells divide and produce prototrophic colonies. These colonies are crossed individually with a wildtype strain. Two types of results are obtained:(1) prototroph × wild type : progeny all prototrophic(2) prototroph × wild type : progeny 75% prototrophic, 25% adenine-requiring auxotrophsa. Explain the difference between these two types of results.b. Write the genotypes of the prototrophs in each case.c. What progeny phenotypes and ratios do you predict from crossing a prototroph of type 2 by the original ade1auxotroph?
In the model plant Arabidopsis thaliana, the following alleles were used in a cross: T = presence of trichomes t = absence of trichomes D = tall plants d = dwarf plants W = waxy cuticle w = nonwaxy A = presence of purple anthocyanin pigment a = absence (white) The T/t and D/d loci are linked 26 m.u. apart on chromosome 1, whereas the W/w and A/a loci are linked 8 m.u. apart on chromosome 2. A pure-breeding double-homozygous recessive trichomeless nonwaxy plant is crossed with another pure-breeding double-homozygous recessive dwarf white plant. a. What will be the appearance of the F1? b. Sketch the chromosomes 1 and 2 of the parents and the F1, showing the arrangement of the alleles.c. If the F1 is testcrossed, what proportion of the progeny will have all four recessive phenotypes?
A yeast geneticist irradiates haploid cells of a strain thatis an adenine-requiring auxotrophic mutant, caused bymutation of the gene ade1. Millions of the irradiatedcells are plated on minimal medium, and a small number of cells divide and produce prototrophic colonies.These colonies are crossed individually with a wildtype strain. Two types of results are obtained:(1) prototroph × wild type : progeny all prototrophic(2) prototroph × wild type : progeny 75% prototrophic,25% adenine-requiring auxotrophsa. Explain the difference between these two types ofresults.b. Write the genotypes of the prototrophs in each case.c. What progeny phenotypes and ratios do you predictfrom crossing a prototroph of type 2 by the original ade1auxotroph?
Wild-type strains of the haploid fungus Neurospora canmake their own tryptophan. An abnormal allele td renders the fungus incapable of making its own tryptophan.An individual of genotype td grows only when its medium supplies tryptophan. The allele su assorts independently of td; its only known effect is to suppress the tdphenotype. Therefore, strains carrying both td and su donot require tryptophan for growth.a. If a td ; su strain is crossed with a genotypically wildtype strain, what genotypes are expected in the progenyand in what proportions?b. What will be the ratio of tryptophan-dependent totryptophan-independent progeny in the cross of part a?
Consider a maize plant: Genotype C/cm ; Ac/Ac+ where cm is an unstable colorless allele caused by Ds insertion. What phenotypic ratios would be produced and in what proportions when this plant is crossed with a mutant c/c Ac+/Ac+? Assume that the Ac and c loci are unlinked, that the chromosome-breakage frequency is negligible, and the C allele encodes pigment production.
In rice, male sterility is controlled by maternal cytoplasmic elements. This phenotype renders the male part of rice plants (i.e. the stamen) unable to produce fertile pollen; the female parts, however, remain receptive to pollination by pollen from male fertile rice plants. However, the presence of a nuclear fertility restorer gene F restores fertility to male-sterile lines. Give the result(s) of the cross and explain the phenotype of the offspring.
In corn, male sterility is controlled by maternal cytoplasmic elements. This phenotype renders the male part of the corn plants (i.e the tassel) unable to produce fertile pollen; the female parts, however, remain receptive to pollination by pollen from male fertile corn plants. However, the presence of a nuclear fertility restorer gene F restores fertility to male sterile lines Using the cardboard chips, simulate the crosses indicated below. Give the genotypes and phenotypes of the offsprings in each cross, and properly label the nucleus and the cytoplasm of each individual in the cross Legend male sterile cytoplasm Male fertile cytoplasm FF nucleus Ff nucleus ff nucleus A. Male sterile female x FF male Explain the phenotype of the offspring B. Male sterile female x Ff male Explain the phenotype of the offspring
In autotetraploid Chinese primrose (Primula sinensis L.), the gene controlling stigma color is very near the centromere of the chromosome carrying it. The allele G for green stigma is dominant to g for red stigmas. A homozygous green autotetraploid strain is crossed with a homozygous red autotetraploid strain. Each of the F1 GGgg plants would obtain 12 gametes which are 2GG, 8Gg, and 2g. How were these obtained?
In the fungus Neurospora, a strain that is auxotrophic for thiamine (mutant allele t) was crossed with a strain that isauxotrophic for methionine (mutant allele m). Linear asci were isolated and classified into the following groups: a. Determine the linkage relations of these two genes to their centromere(s) and to each other. Specify distances in map units. b. Draw a diagram to show the origin of the ascus type with only one single representative (second from right).
You make a test cross between an F1 plant that is heterozygous for two dominant resistance genes (R1 and R2) and a line that is homozygous recessive at both loci, and inoculate the progeny with a pathogen race that is avirulent on both R1 and R2 (i.e., it carries avirulence genes Avr1 and Avr2).You get 50 susceptible progeny out of 200 test cross progeny. (a) What is the linkage phase for these two genes? (b) What is the recombination distance?
A geneticist examines an ear of corn in which most kernels are yellow, but he finds a few kernels with purple spots, as shown here. Give a possible explanation for the appearance of the purple spots in these otherwise yellow kernels, accounting for the different sizes of the spots.
In fruit flies, you are mapping three genes in a three point cross. The mutants are hairy body (h), sepia colored eyes (se) and female sterility (g). You cross a heterozygous parent with a homozygous recessive parent and obtain the following results: Type Number h se g. 5 + se + 450 + se g 27 ++g_ h se + + + + h + g. h + + TOTAL is the gene in the middle and the distance in map units between se and g is Oh; 16.4 se; 7.1 Oh; 7.1 70 82 7 327 32 1000 se; 16.4