Answer:
1. D
2. C
Step-by-step explanation:
1. D. Dominant and recessive traits
Rationale:
Purple is a dominant trait while white is recessive. Therefore, the parent plants are most likely has an allele for purple and white. The purple allele expresses itself over the white allele in the parent plants that's why they are both purple. Whereas, when they cross, they produce offsprings whereby some have white colours and others have purple colours.
The ones with white colours have double alleles of the recessive allele.
2. C. Expression of both alleles
Rationale:
For example, when you cross a red flower with a white flower, codominance has occured if the resulting offspring is a white-spotted red flower which has an allele for each colour expressing itself.