What's the difference between the three types of translocations? (Balanced, unbalanced, and Robertsonian)

7.18 In Drosophila, the genes st (scarlet eyes), ss (spineless bris- tles), and e (ebony body) are located on chromosome 3, with map positions as indicated: SS e 58 70 st 44 Each of these mutations is recessive to its wild-type allele (st+, dark red eyes; sst, smooth bristles; et, gray body). Phenotypically wild-type females with the genotype st ss et/st stt sste were crossed with triply recessive males. Predict the phenotypes of the progeny and the frequen- cies with which they will occur assuming (a) no interfer- ence and (b) complete interference.

What happens in the absence of tryptophan in the 2-3 configuration?

Nicotiana tabacum is presumed to be an allotetraploid originating from a cross between N. sylvestris (the S genome) and N. tomentosa (the T genome). Each of the two parental species (2n = 24) contributed 12 chromosomes (S & T), which then doubled to form the 24 pairs of chromosomes observed in N. tabacum. a) Diagram the entire cross starting with the original parents until the formation of N. tabacum. Distinguish between chromosomes of N. sylvestris and N. tomentosa and give the chromosome number of all individuals in the cross. Include gametes in your crosses. b) A monosomic N. tabacum is crossed with N. sylvestris and produces offspring, some with 36 chromosomes and some with 35 chromosomes. Using cytological examination at meiosis, the 35-chromosome types show 11 bivalents and 13 univalents. Is this plant monosomic in the S or T genome? Show why it cannot be the other genome as part of your solutions