To determine: The interpretation made by the given results and also estimate their mode of inheritance.
Introduction: The fruit-shaped plant Plectritis congesta is of two types. One individual can bear the wingless fruits, whereas another can bear the winged fruits. The three plants which were collected at random (before flowering) from nature were crossed to find out the dominant as well as a recessive character among fruits.
To determine: The nongenetic explanations for the specified
Introduction: Nongenetic characters or inheritance are called the characters, which are not exhibiting the same trait or not relayed to their genetics (or 'missing heritability). The other factors influence such types of behaviors.
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INTRO TO GEN ANALYSIS W/ACHIEVE ACCESS
- In the Roselle plant, the dominant allele of gene 'A' codes for a pink flower and the recessive form codes for yellow flowers, while the dominant form of gene 'B' codes for serrated leaves, while the recessive form codes for smooth leaves. If the genes are trans linked, what are the expected genotypes and phenotypes and the respective ratios when plants heterozygous for both genes are test crossed?arrow_forwardA pure breeding strain of squash that produced disk-shaped fruits was crossed with a pure- breeding strain having long fruits. The first filial generation had disk fruits, but the second filial generation showed a new phenotype, sphere, and was composed of the following proportions: disk 270, sphere 178, long 32. Propose an explanation for these results, and show the genotypes of P, First filial generation and second filial generation.arrow_forwardIn 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 phenotypes? Diagram the purple * purple cross.arrow_forward
- J. W. McKay crossed a stock melon plant that produced tan seeds with a plant that produced red seeds and obtained the following results (J. W. McKay. 1936. Journal of Heredity 27:110–112). Cross F1 F2 tan ♀ × red ♂ 13 tan seeds 93 tan, 24 red seeds a. Explain the inheritance of tan and red seeds in this plant. b. Assign symbols for the alleles in this cross and give genotypes for all the individual plants.arrow_forwardFlower color in petunias is determined by the biochemical pathway shown below: A_ B_ C_ Yellow Orange > Green Blue aa bb Plants of genotype AAbbcc were mated to plants of genotype AaBbCc. Determine the phenotypic ratio expected from this cross and fill in the spaces in the ratio below with whole numbers in lowest form. lf none are expected in a class, then type the number 0 in the space. Yellow: Orange : Green: Bluearrow_forwardMendel's concept of dominance states that in a genotype where two different alleles of a locus are present, only the trait encoded by the dominant allele is observed. Give a molecular explanation for dominance, i.e. explain intracellular molecular events that can result in what we observe as dominance on a phenotypic level. Use the gene that encodes seed shape in peas as an example, where roun(R) is dominant over wrinkled(r), to explain how RR and Rr plants can have the same phenotype.arrow_forward
- Assume that, in a series of experiments, plants with round seeds were crossed with plants with wrinkled seeds and the following offspring were obtained: 215 round and 185 wrinkled. How do you explain these observations and what would be the expected number of offspring with round seed and with wrinkled seed? The plants with round seeds are heterozygous for the round seed phenotype and F1 offspring is expected to show 200 round and 200 wrinkled seed. The plants with round seeds are homozygous for the round seed phenotype and F1 offspring is expected to show 300 round and 100 wrinkled seed. The plants with round seeds are heterozygous for the round seed phenotype and F1 offspring is expected to show 100 round and 300 wrinkled seed. The plants with round seeds are homozygous for the round seed phenotype and F1 offspring is expected to show 200 round and 200 wrinkled seed. The plants with round seeds are heterozygous for the round seed phenotype and F1 offspring is…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_forwardIn Drosophila, a cross was made between females—all expressing the three X-linked recessive traits scute bristles (sc), sable body (s), and vermilion eyes (v)—and wild-type males. In the F1, all females were wild type, while all males expressed all three mutant traits. The cross was carried to the F2 generation, and 1000 offspring were counted, with the results shown in the following table. Phenotype Offspring sc s v 314 + + + 280 + s v 150 sc + + 156 sc + v 46 + s + 30 sc s + 10 + + v 14 No determination of sex was made in the data. (a) Using proper nomenclature, determine the genotypes of the P1 and F1 parents. (b) Determine the sequence of the three genes and the map distances between them. (c) Are there more or fewer double crossovers than expected? (d) Calculate the coefficient of coincidence. Does it represent positive or negative interference?arrow_forward
- In corn, a pair of genes determines leaf shape and another pair determines pollen shape. A ragged-leafed plant with round-pollen was crossed to a ragged-leaf plant with angular pollen, and the resultant progeny were classified as follows: 186 ragged-leaf round-pollen 174 ragged-leaf angular pollen 57 smooth-leaf round pollen 63 smooth-leaf angular-pollen provide your hypothesis of the genotypes for the two parents. According to your hypothesis, what numbers would you have expected for each of the four classes of progeny? Follow the format of the number with the phenotypes in the question above. Test your hypothesis statistically using the chi-square method and indicate whether you accept or reject your hypothesis. Show your solutions.arrow_forwardIn 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?arrow_forwardMale Drosophila from a true-breeding wild-type stock were irradiated with X-rays and then mated with females from a true-breeding stock carrying the following recessive mutations on the X chromosome: yellow body (y), crossveinless wings (cv), cut wings (ct), singed bristles (sn), and miniature wings (m). These markers are known to map in the order: Recessive alleles: y, cv, ct, sn, m Dominant alleles: y+, cv+, ct+, sn+, m+ y-cv-ct-sn-m у CV ct sn m X-rays х х X ct sn CV у m y+ CV+ ct+ sn+ m+ х X ? Exceptional female: Most of the female progeny of this cross were phenotypically wild type, but one female exhibited ct and sn mutant characteristics. When this exceptional ct sn female was mated with a male from the true-breeding wild-type stock, twice as many females as males appeared among the progeny. a. What is the nature of the X-ray-induced mutation present in the exceptional female? b. Draw the X chromosomes present in the exceptional ct sn female as they would appear during pairing…arrow_forward
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