Part A: Monohybrid problems concerning tomato.
Given: • Tall stature is dominant over dwarf stature (D, d). • Smooth-skinned fruit is dominant over peach (hairy) fruit (P, p). • Oblong fruit shape is dominant over normal fruit shape (O, o). • Simple inflorescence is dominant over compound inflorescence (S, s). • Purple stem is dominant over green stem (A, a). • Fasciated fruit (consisting of may chambers) is dominant over nonfacciated fruit (F, f) • Red-fleshed fruit is dominant over yellow-fleshed fruit (R, r). • Opaque skin, as in bright fruit, is dominant over transparent skin, as in dull fruit (Y, y). Note: The genes for stature, skin type, fruit shape, and inflorescence belong to one linkage group (that is, they are all inherited together); genes for stem color and fasciation belong to another linkage group. Genes R and Y are independent of these linkage groups and of each other.
7) Why are certain genes usually inherited together? (that is, what is a linkage group?)
a) A homozygous tall tomato plant (genotype: ___________) is pollinated by a
homozygous dwarf plant (genotype: ______________).
1) What allele(s) will be carried by the pollen grain nuclei? _____________
By the egg nuclei? ______________
2) What will be the genotype of the first filial generation (F1)? ______________.
3) What will be its stature (phenotype)? _____________________.
4) If the F1 genetation is self-pollinated, what will be the appearance (phenotype) of the second filial generation (F2). ________________________.
5) What alleles were carried by the pollen grains of the F1 parents? ___________
By the eggs of the F1 parents? ___________________? For the F2 generation, the
genotypic ratio is _____________ and the phenotypic ratio is ________________.
b. A tall tomato plant is pollinated by a dwarf tomato plant. About half the progeny are tall plants and half are dwarf plants.
13. What are the genotypes of the parents? Tall ___________________.
Of the progeny? _______________
the only thing I do not understand is how to determine which allele came from the pollen grain and from the egg #'s 1 and 5
7. Genes are inherited together if they occur on the same chromosome and are close enough that crossing over may not separate... View the full answer