Question

Choose the correct answer from the alternatives given.
Fruit shape in a shepherd's purse (Capsella bursa) is of two types – triangular and top-shaped. Triangular fruit shape (T) is dominant over top-shape (t).

The following table summarises the results of several crosses.
             Cross result
A. Strain \[1\] \[ \times \] tt all triangular
B. Strain \[2\]\[ \times \] tt triangular: \[1\] top-shaped
C. Strain \[3\] \[ \times \] tt all top-shaped
 D. Strain \[4\] \[ \times \] tt\[3\] triangular: \[1\] top-shaped

Which pair of strains possess the genotypes Tt?
A. Strains \[2\] and \[3\]
B. Strains \[2\] and \[4\]
C. Strains \[1\] and \[3\]
D. Strains \[1\] and \[4\]

Answer 1

Hint: Polyploidization and next and neofunctionalization of duplicated genes mainly constitute a sort of the main mechanism of plant genome evolution in an honestly foremost way. Capsella bursa‐pastoris, a widespread surely ruderal plant, definitely is a latest allotetraploid and, consequently, essentially is a simple best model organism for analyzing early changes following polyploidization, which is reasonably tremendous.

Complete answer:
The pressure \[2\] that for all intents and functions has one triangular and one generally top-shaped fruit will essentially have the genotype ''Tt' which for the most element is heterozygous and outcomes as a result with a pass recessive genotype 'tt' two genotype the 'Tt' and 'tt' to for all intents and functions supply the triangular and pinnacle-shaped fruit respectively, quite contrary to famous belief. The stress four additionally definitely has heterozygous 'Tt' genotype and could essentially give with the go of 'tt' \[3\] heterozygous and one recessive genotype and consequently three triangular and \[1\] top fashioned fruit, very similarly showing how the stress \[4\] also really has heterozygous 'Tt' genotype and will supply with the cross of 'tt' three heterozygous and one recessive genotype and for this reason, three triangular and \[1\] the very pinnacle formed fruit hugely.

Hence, the correct answer is option (B).

Note: The genus Capsella Medik honestly is quite specific family member Brassicaceae having compressed obcordate fruits, which for all intents and purposes within reason are good sized which particularly is quite giant. In India, the genus truly is represented with the aid of only the species Capsella bursa-pastoris, for all intents and purposes contrary to famous belief. generally essentially located in the pretty sub-tropical to alpine forests at some stage in the Himalayas and the Western Ghats in a massive way.