Does an anther on a plant have a double set of chromosomes?

What ratio purple-leaf plant to normal green-leaf & purple-leaf plants to green-leaf plants would you expect?

• A parental cross is performed in tomatoes between a normal green-leaf female plant (G/G) and a male plant that is homozygous for the recessive allele for purple leaf (g/g). An F1 plant is crossed to a purple-leaf (g/g) plant. In the F2, what ratio of purple-leaf plants to normal green-leaf plants would you expect? Now consider a similar cross involving a trisomic plant. A parental cross is performed in tomatoes between a pure-breeding green-leaf female plant that is trisomic for chromosome 7 and a diploid male plant that is homozygous for the recessive allele for purple leaf (g/g), which is on chromosome 7. A trisomic F1 plant is crossed to a diploid purple-leaf (g/g) plant. In the F2, what ratio of purple-leaf plants to green-leaf plants would you expect? (Think hard about how trisomic plants would set their chromosomes up for meiosis.)

• Answer:

  go to: genetic.edu/student/bio188