In maize, the recessive genes su and sh (when homozygous) produce sugary and shr

Question

In maize, the recessive genes su and sh (when homozygous) produce sugary and shrunken endosperm, respectively. Their dominant alleles Su and Sh produce normal starchy and full endosperm. A true breeding sugary variety is crossed to a pure breeding shrunken variety.

a) In this cross, what is the genotype and the phenotype of the F1 generation?

b) Diagram the TEST CROSS of this F1, and indicate both the GENOTYPE and PHENOTYPE of the progeny. Please use a Punnett Square to diagram this cross. (3 pt)

Explanation / Answer

A true breeding sugary variety is crossed to a pure breeding shrunken variety.

Genotype of Parents: susu shsh x susu shsh

a) genotype of the F1 generation: susu shsh.

phenotype of the F1 generation: sugary and shrunken.

b) TEST CROSS of this F1: susu shsh x Susu Shsh

                 sush                   sush             sush         sush

SuSh       SusuShsh       SusuShsh     SusuShsh        SusuShsh

suSh       susuShsh         susuShsh      susuShsh        susuShsh

Sush       Susushsh         Susushsh      Susushsh       Susushsh

sush       susushsh          susushsh      susushsh         susushsh

GENOTYPE of the progeny: SusuShsh, susuShsh, Susushsh, susushsh

PHENOTYPE of the progeny: SusuShsh - Normal starchy and full endosperm

susuShsh - sugary and full endosperm

Susushsh - Normal starchy and shrunken endosperm

susushsh - sugary and shrunken endosperm

Related Questions

Navigate

• Browse (All)
• Browse I
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.