Which part of the calvin cycle would be affected if a cell could not produce the enzyme
rubisco)?

The first step also referred to as Carbon Fixation

Explanation:

RuBisCo is an enzyme that catalyzes the attachment of carbon molecule to ribulose phosphate (RuBp) forming the 6-carbon molecule that immediately splits into two 3-carbon molecules of 3-phosphoglycerate (3-PGA).  

answer; a male inherits only one allele of the x-linked gene controlling hair color;