Answer:
1) Incomplete dominance;
2) Purple rose and blue rose will be produced as offsprings in the ratio 1:1
Step-by-step explanation:
The trait for flower color in roses is controlled by a single gene whose alleles exhibits incomplete dominance. INCOMPLETE DOMINANCE is an inheritance pattern in which one allele is incompletely dominant i.e. incapable of masking the expression, over another allele, hence, they both blend to form an hybrid with a different third phenotype. In this case, red allele (R) is incompletely dominant to blue allele (R'), they form a different phenotype hybrid with genotype (RR'), purple rose.
Hence, the inheritance pattern of the gene responsible for the rose flower color trait is INCOMPLETE DOMINANCE.
According to the second question, if Fitz crossed a blue rose (R'R') with a purple rose (RR'), each parent will produce the following gametes:
R'R'- R' and R'
RR'- R and R'
Using these gametes in a punnet square (see attached image), 4 offsprings will be produced with two having genotype: R'R' while the other two will have genotype: RR'. The R'R' offsprings will be phenotypically blue while the R'R' offsprings will be phenotypically purple.
Hence, the phenotypic and genotypic ratio of both offsprings will be 2:2 equivalent to 1:1.