Concept explainers
a.
To determine: The length of the first and second hybrid stems under blending theory.
Introduction: Mendel was known as the father of genetics. Mendel worked on the garden pea and consider it’s seven characteristics, such as flower color, seed color, height, and seed shape. Mendel took two variants of height long and short in which he observed that the dominant character always concealed the other form.
b.
To determine: The observation in second-generation hybrids if all the first-generation hybrids are tall.
Introduction: Mendel, while experimenting on the garden pea, gave three basic laws of inheritance. The laws are the law of segregation, the law of dominance, and the law of independent assortment. The alleles that are identical to each other are known as homozygous, while two different alleles are known as heterozygous.
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Check out a sample textbook solution- Mendel studied a tall variety of pea plants with stemsthat are 20 cm long and a dwarf variety with stems thatare only 12 cm long.a. Under blending theory, how long would you expectthe stems of first and second hybrids to be?b. Under Mendelian rules and assuming stem lengthis controlled by a single gene, what would you expectto observe in the second-generation hybrids if all thefirst-generation hybrids were tall?arrow_forwardIn Mendel’s pea plants, axial (A) flowers are dominant over terminal (a) flowers. a. What is the genotype of a homozygus axial parent plant? b. What is the genotype of a homozygous terminal parent plant? If the parents in (a) and (b) are crossed, what is the genotype and phenotype of the F1? c. Genotype: d. Phenotype: If the F1s are selfed, determine the following: e. F2 genotypes ____________________ __________________________________________ ______________________f. F2 Phenotypes ____________________ __________________________________________ ______________________g. What is the F2 genotypic ratio? h. What is the F2 phenotypic ratio?arrow_forwardMendel obtained his initial pea plant varieties from local breeders who were developing new varieties that might be useful or interesting. To generate these new varieties, breeders formed hybrids between existing varieties of different phenotypic characteristics by cross pollination, using techniques they doubtless taught to Mendel. After producing a hybrid, they allowed several generations of self-pollination, as happens naturally if the flowers are not disturbed. b. What if a breeder were working with 7 different, independently segregating genes, as Mendel did? How many generations would it take him to have pure-breeding varieties, starting from an F1 hybrid that is heterozygous for all 7 genes? i. What is the probability that an individual in the F2 generation would be pure-breeding (i.e. is homozygous at all 7 loci)? ii. What is the probability that an individual in the F3 generation would be pure-breeding? iii. What is the probability that an individual in the F10…arrow_forward
- Mendel began his work with pairs of varieties from the breeders that differed from each other in just one trait (corresponding to one gene difference, as we now know) out of the 7 traits he studied. These pairs could be obtained by self-pollinating an individual from an advanced generation that was pure-breeding for 6 of the traits but heterozygous for the 7th. i. What is the probability of finding an example plant in the F10 generation? ii. What is the probability of finding an example plant in the F4 generation? [Note: this probability is higher than that for the F10 generation or the F3 generation. What qualitative reason might there be?arrow_forwardIn peas, tall is dominant over dwarf. If a plant homozygous for tall is crossed with one homozygous for dwarf : a. What will be the genotype(s) (use the initial of your last name) and phenotype (s) of the F1 plants? b. If the F1 is grown the next season, predict the possible genotypes and phenotypes. c. If you cross the F1 to the tall parent, what phenotype will result of the cross? What will be the ratio of the genotype? d. If you cross the F1 to the short parent, what phenotype will result of the cross? What will be the ratio of the genotype?arrow_forwardConsider a plant that has the "Leaf" gene (L) that causes leaves to be either smooth or wrinkled and is inherited through complete dominance. Heterozygotes of the L gene are smooth. A. What are the two alleles of the gene? B. What is the recessive phenotype? C. What is the genotype of a homozygous dominant individual? D. What gametes can a heterozygous individual make? E. Make a Punnett square to predict the percentage or fraction of recessive progeny when two heterozygous individuals are mated. WHOITICS0OTAarrow_forward
- A) Describe the data you collect from the Purple 1 x Purple 2 cross. Predict the genotype of each of the parent plants. Explain your predictions using data from the experiment. B) Consider the offspring, the next generation (F1), from the Purple 1 x Purple 2 cross. What is the probability of a green stem plant? How do you know this? C) What is the probability in the F2 generation of a green stem offspring? Use a Punnett square(s) and quantitative data to explain your thinking. Upload your Punnett square(s).arrow_forwardYou inspect an ear of corn and find the following number of kernels: 461 red and starch, 142 red and sweet, 156 yellow and starchy and 53 yellow and sweet. a. What genotype did the parent corn plants probably have? b. Support your answer by working out the cross with a Punnett squarearrow_forwardIn a genetic cross between a homozygous tall plant with homozygous purple flowers and a homozygous short plant with heterozygous purple flowers, how many short plants will you expect in the F2 generation if you sample 36 individuals? Both tall and purple are dominant.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 (E. W. Lindstrom. 1921. Genetics 6:91–110). a. Give the genotypes for the green, virescent-white, and yellow progeny. b. Explain how color is determined in these seedlings. c. Is there epistasis among the genes that determine color in the corn seedlings? If so, which gene is epistatic and which is hypostatic?arrow_forwardIn sweet peas, the synthesis of purple anthocyanin pigment in the petals is controlled by two genes, B and D. What petal color would you expect in a pure breeding plant unable to catalyze the first reaction? Indicate the genotype and phenotype. 2. What petal color would you expect in a pure breeding plant unable to catalyze the second reaction? Indicate the genotype and phenotype. 3. If plants 1 and 2 are crossed, what petal color would the F1 plants have? Indicate the genotype and phenotype. 4. What ratio of purple : blue : white plants would you expect in the F2? Indicate the genotypes, phenotypes, and the F2 phenotypic ratio.arrow_forwardA test cross between a plant of genotype PpSs and the tester white plant with wrinkled seed coat (ppss) gives the following numbers of progeny in four phenotypic types. 14:87:83:16 (purple flower + smooth seed coat: purple flower + wrinkled seed coat: white flower + smooth seed coat: white flower + wrinkled seed coat). a. What is the expected ratio of progeny phenotypes assuming independent assortment of alleles? b. Explain how ratios of progeny show that the two genes are linked. c. How many map units separate the purple and smooth genes? Show your calculations. d. What is the “parental” genotype of the heterozygous parent? (i.e. Which alleles of the P and S loci are present on each of the two chromosomes of the doubly heterozygous parent of this test cross?)arrow_forward
- Concepts of BiologyBiologyISBN:9781938168116Author:Samantha Fowler, Rebecca Roush, James WisePublisher:OpenStax College