You have a purple-flowered pea plant, but you do not know if it is homozygous (PP) or heterozygous (Pp) for flower color because both genotypes result in the same purple phenotype. Purple color allel (P) is dominant over white flower allel (p). What would you do to determine the genotype of flower color of this plant? Löffen birini seçin: a. Crossing the plant with homozygous large flowered pea plant (LL) O b. Crossing the plant with heterozygous purple flowered pea plant (Pp) c. Crossing the plant with homozygous dominant purple flowered pea plant (PP) O d. Crossing the plant with a plant whose genotype is unknown Oe. Crossing the plant with homozygous recessive white flowered pea plant (pp)

In watermelons there is a gene for colour and a gene for shape located on different chromosomes. The alleles for green colour and for short shape are dominant over their alleles for striped colour and for long shape. Suppose a plant with long striped fruit is crossed with a plant heterozygous for both these characters. What phenotypes would this cross produce and in what ratios?

Sometimes, two alleles are neither dominant nor recessive, therefore, both alleles are expressed separately in a heterozygous individual. This is called codominance. Which of the following is an example of codominance? a In guinea pigs, black hair is dominant over white hair. A homozygous black guinea pig is crossed with a homozygous white guinea pig. The first generation of offspring are black. b If you cross a plant with blue flowers with a plant with yellow flowers, the offspring will have blue flowers with yellow spots. c If you cross a rhododendron plant with red flowers with a rhododendron plant with white flowers, the offspring will have pink flowers. d A white female cat mates with a brown male cat. The resulting offspring are orange.

A 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.