Question

14. Trisomy of chromosome 3 occurs somewhat regularly in the plant Datura, and results in a viable offspring. However, the phenotype of euploid Datura differs from that of trisomy 3 Datura, making it relatively easy to tell when an offspring carries this trisomy. A researcher growing Datura notices that one of the offspring produced following a controlled pollination appears to be carrying trisomy 3. She therefore genotypes the mother and father of this offspring at a marker locus on chromosome 3: Mother's marker genotype = 120, 200 Father's marker genotype = 90, 160

Answer 1

14b)

The Father's markers for Chromosome 3 are 90 and 160 and the Mother's Markers are 120 and 200.

Therefore, the cells produced in the father after Meiosis I will have both these markers (90 & 160).

The progeny produced from this cross will have the genotype 90, 160, 120 or 90, 160, 200.