In a cross between pure-breeding tall plants with pure-breeding short plants performed by Mendel, all of the F1 are tall. When these plants are allowed to fertilize themselves, the F2 plants occur in a ratio of 3 tall to 1 short. Which of the following is NOT a valid conclusion from these results? O A. The allele that produces the tall condition is dominant to the allele that produces the short condition. O B. The difference between tall and short stature in these lines is controlled by a single gene pair. O C. Fertilization occurs randomly between gametes carrying the tall and short alleles. D. The tall and short traits assort independently of each other in this cross. E. During production of gametes in F1 plants, the tall and short alleles segregate from each other equally into the gametes. Reset Selection VMark for Review What's This?

In triffid plants, the color trait and the spikiness trait are controled by two loci that assort independently. A true-breeding smooth green strain of triffids is crossed to a true-breeding spiky orange strain of triffids.  All of the F1 are spiky green.  The geneticist then performs two additional crosses: 1. she allows the F1 to self-fertilize 2. she crosses a plant from the F1 to a smooth orange strain. Choose all statements that are TRUE: Group of answer choices orange is dominant spiky is dominant all the progeny resulting from cross 1 (the selfing) will be smooth all the plants resulting from cross 2 will be orange green is dominant all the progeny resulting from cross 1 (the selfing) will be spiky smooth is dominant there will be mixture of smooth and spiky plants in the progeny resulting from cross 1 (the selfing) All the plants resulting from cross 2 will be green there will be a mixture of green and orange plants in the progeny resulting from cross 2

In a dihybrid cross of two bi-allelic Mendelian genes, A (two alleles – completely dominant A and recessive a), and B (two alleles – completely dominant B and recessive b), such that the parental generation comprises of pure-bred homozygotes (i.e. AABB with aabb), what are the expected genotype and phenotype ratios in the F1 and F2, if the F1 cross is (a) an intercross and if the F1 cross is (b) a testcross

Assume that the length of a type of cucumber at maturity is controlled by two genes (A and B), each of which has two alleles. The A and B alleles each add 3 inches of cucumber growth, while the a and b alleles add only 1 inches. If a plant with genotype Aabb is crossed to a plant with genotype AaBb, what ratios of lengths are expected in the progeny?     1/8-12”, 3/8-10”, 3/8-8”, 1/8-6”     1/2-8”, 3/8-6”, 1/8 4”     1/8-10”, 3/8-8”, 3/8-6”, 1/8-4”     1/2-12”, 3/8-10”, 1/8 8”     1/2-10”, 3/8-8”, 1/8 6”

Mendel 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. a. How many generations would it take for a breeder to have produced new pure-breeding varieties using this approach?       b. What is the probability that an individual in each of these generations (F2, F3, and F10) would be homozygous for one or the other allele of this gene?

Mendel crossed true breeding pea plants. One parent had round, green, seeds, and the other had wrinkled, yellow seed. All F, plants had seeds that were round and yellow. Predict the results of F2 plants, using a Punnet square or tree diagram. a. What are the results as a ratio? A What are the results as fractions?

In the tomato, yellow flowers (Y) is dominant to white flowers (y). A true-breeding yellow flowered strain is crossed with a true-breeding white flowered strain.A. If the F1 generation is self crossed, what will be the genotypes and phenotypes of the progeny and in what portions are they expected? B. If an F1 plant were crossed with a plant from true-breeding white flowered strain, what will be the genotypes and phenotypes of the progeny and in what portions are they expected?

In classical Mendelian genetics, how can one check the genotype of a parent (A) expressing the characters of a dominant allele?   Select one: a. By performing a back cross with a recessive homozygote parent (B). If the A parent is homozygote for the dominant allele, then all the individuals from the F1 will display the dominant character. If the parent A was, instead, a heterozygote, then 50% of the F1 progeny will express the recessive character (homozygote recessive) and 50% the dominant one (heterozygotes). b. It is impossible to check such genotype without using specific molecular assays. c. By performing a back cross with a dominant homozygote parent (B). If the A parent is homozygote for the dominant allele, then all the individuals from the F1 will display the dominant character.

Red-flowering snapdragons are homozygous for allele R1. White-flowering snapdragons are homozygous for  a different allele (R2). Heterozygous plants (R1R2) bear pink flowers. What phenotypes should appear among first-generation offspring of the crosses listed? What are the expected proportions for each phenotype? a. R1R1 × R1R2 c. R1R2 × R1R2 b. R1R1 × R2R2 d. R1R2 × R2R

Mendel examined two distinct flower phenotypes in his pea plants. Flower color and flower position. The violet color (W) is dominant over the white color (w), and the axial position (T) is dominant over terminal (t). Predict the F1 ratios of these phenotypes from a parent heterozygous for both traits and the other parent homozygous recessive for both traits. Show your work. Flower color Flower position violet/white axial/terminal