A diploid plant species has a gene controlling petal colour with three alleles: CRC^RCR, CWC^WCW, and CYC^YCY. The alleles CR C^R\,CR and CW C^W\,CW are codominant (producing pink petals when inherited together), while CY C^Y\,CY is recessive to both.
Which of the following statements regarding the inheritance of this trait is correct?
A cross between a pink-flowered plant (CRCWC^R C^WCRCW) and a white-flowered heterozygous plant (CWCYC^W C^YCWCY) will yield offspring with a phenotypic ratio of 1 red : 2 pink : 1 white.
In a population of these plants, there are six possible genotypes but only four distinct phenotypes for this gene.
A cross between two pink-flowered plants can produce offspring with yellow petals (CYCYC^Y C^YCYCY) if both parents carry the recessive CYC^YCY allele.
Because there are three alleles for this gene, a single male gamete (pollen grain) from a heterozygous plant can carry up to two different alleles.