Concept explainers
In some plants a red flower pigment, cyanidin, is synthesized from a colorless precursor. The addition of a hydroxyl group (OH−) to the cyanidin molecule causes it to become purple. In a cross between two randomly selected purple varieties, the following results were obtained:
94 purple
31 red
43 white
How many genes are involved in the determination of these flower colors? Which genotypic combinations produce which
Want to see the full answer?
Check out a sample textbook solutionChapter 4 Solutions
Concepts of Genetics (12th Edition)
Additional Science Textbook Solutions
Laboratory Manual For Human Anatomy & Physiology
Biology: Life on Earth with Physiology (11th Edition)
Microbiology Fundamentals: A Clinical Approach
Human Physiology: An Integrated Approach (8th Edition)
General, Organic, and Biological Chemistry: Structures of Life (5th Edition)
- In an intra-species cross performed in mustard plants of two different species (Brassica juncea and Brassica oleracea), a tall plant (TT) was crossed with a dwarf (tt) variety in each of the two species. The members of the F1 generation were crossed to produce the F2 generation. Of the F2 plants, Brassica juncea had 60 tall and 20 dwarf plants, while Brassica oleracea had 100 tall and 20 dwarf plants. Use chi-square analysis to analyze these results.arrow_forwardThere are some members of the genus Datura that are trisomic for the chromosome set, which carries the genes for purple (p+) and white (p) flower color. In a cross involving a trisomic p+ p+ p female and pollen from a normal p+ p plant, what is the expected proportion of purple and white flowered individuals?arrow_forwardConsider this cross in pea plants: Tt Rr yy Aa × Tt rr Yy Aa, whereT = tall, t = dwarf, R = round, r = wrinkled, Y = yellow, y = green,A = axial, a = terminal. What is the expected phenotypic outcomeof this cross? Have one group of students solve this problem bymaking one big Punnett square, and have another group solve it bymaking four single-gene Punnett squares and using the multiplication method. Time each other to see who gets done first.arrow_forward
- In some plants, a true-breeding, red-flowered variety gives all pink flowers when crossed with a white-flowered strain: RR (red) X rr (white) = Rr (pink). Flower position in this plant may either be axial (dominant) or terminal (recessive). What will be the phenotypic ratios of the F1 generation resulting from the following cross: axial-red (true-breeding) X terminal-white? What will the phenotypic ratios of the F2 be? SHOW ALL WORKarrow_forwardIn corn, the allele f ′ causes floury endosperm and the allele f ″ causes flinty endosperm. In the cross f ′/f ′ ×f ″/f ″, all the progeny endosperms are floury, but, in the reciprocal cross, all the progeny endosperms are flinty. What is a possible explanation? (Check the legend for Figure 2-7.)arrow_forwardIn 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.arrow_forward
- Three autosomal recessive mutations in yeast, all producing the same phenotype (m1, m2, and m3), are subjected to complementation analysis. Of the results shown below, which, if any, are alleles of one another? Predict the results of the cross that is not shown—that is, m2 * m3. Cross 1: m1 * m24 F1: all wild-type progeny Cross 2: m1 * m34 F1: all mutant progenyarrow_forwardA purple flowering, smooth seed dihybrid plant (genotype PpSs) is test crossed with a white flowering, wrinkled seed plant (genotype ppss). These produce progeny in the following numbers of four phenotypes: 24:76:74:26 (purple flower + smooth seed coat: purple flower + wrinkled seed coat: white flower + smooth seed coat: white flower + wrinkled seed coat). a) What is the genotype of the original dihybrid plant? Specify which alleles are on each chromosome of the purple flowering, smooth seed plant (i.e. AB/ab or Ab/aB). b) How many map units separate the colour and seed coat genes? Show your calculations.arrow_forwardMendelian ratios are modified in crosses involving autotetraploids.Assume that one plant expresses the dominant trait greenseeds and is homozygous (WWWW). This plant is crossed to onewith white seeds that is also homozygous (wwww). If only onedominant allele is sufficient to produce green seeds, predict theF1 and F2 results of such a cross. Assume that synapsis betweenchromosome pairs is random during meiosis.arrow_forward
- E. W. Lindstrom crossed two corn plants with green seedlings and obtained the following progeny: 3583 green seedlings, 853 virescentwhite seedlings, and 260 yellow seedlings . Q. Explain how color is determined in these seedlings.arrow_forwardIn the snail Limnaea peregra, coiling of the shell is determined by the genes D for right-hand coiled shells, and d for left-hand coiled shells. The gene for the right-hand coiled shell is dominant. The direction of coiling is determined by the genotype of the maternal parent producing the egg, regardless of the progeny's genotype. Which of the following crosses could give a left-hand coiled shell heterozygote? A. right-hand coiled dd female X left-hand coiled DD male B. left-hand coiled DD female X right-hand coiled dd male C. left-hand coiled DD female X left-hand coiled DD male D. right-hand coiled dd female X left-hand coiled dd malearrow_forwardE. W. Lindstrom crossed two corn plants with green seedlings and obtained the following progeny: 3583 green seedlings, 853 virescentwhite seedlings, and 260 yellow seedlings . Q. Is there epistasis among the genes that determine color in the corn seedlings? If so, which gene is epistatic and which is hypostatic?arrow_forward
- Human Biology (MindTap Course List)BiologyISBN:9781305112100Author:Cecie Starr, Beverly McMillanPublisher:Cengage LearningConcepts of BiologyBiologyISBN:9781938168116Author:Samantha Fowler, Rebecca Roush, James WisePublisher:OpenStax CollegeBiology (MindTap Course List)BiologyISBN:9781337392938Author:Eldra Solomon, Charles Martin, Diana W. Martin, Linda R. BergPublisher:Cengage Learning
- Human Heredity: Principles and Issues (MindTap Co...BiologyISBN:9781305251052Author:Michael CummingsPublisher:Cengage Learning