Youre an orchid breeder and have noticed that you have a few

You’re an orchid breeder and have noticed that you have a few plants that display a totally novel golden coloring pattern. This purple and gold pattern has basically made you a LEGEND in your horticulture club, and now your best friend wants to use your sweet orchids in their wedding. Obviously, getting a pure breeder line would be ideal for cranking up production… because your pal is going to need A LOT of flowers. But this is providing to be a challenge; every time two golden orchids are crossed, you end up with a fair number of gold flowers, but still a significant number of orchids featuring the standard white coloration. In your most recent purple and gold orchid self cross, you ended up with 113 gold and 57 standard orchids. All other such mating’s gave similar phenotypic offspring ratios. What’s going on here? Explain why you think that in at least 4 sentences?

Solution

Since there are three colours involved, we can assume that multiple alleles for a single trat (in this case - flower colour) is at play here. The golden and purple colours both seem to be dominant over the regular white colour. In this case, white flower colour is recessive. Therefore, when a flower receives the parental alleles, one of the allele must be coding for either golden or purple. Hence, the breeder is obtaining golden and purple colored flowers. As to the second part of the question, the breeder does not possess true breeding golden, or true breeding purple plants. The plants which he does possess are heterzygous, carrying alleles for all the three characteristics in its genotype, Therefore, the breeder obtains all the variants on self crossing.