Question

2) Matthew also planted four o'clocks. All of his seeds came from one set of parents. When his plants bloomed, 50% were white and 50% were pink. What were the genes of the parent plants?

3. When Sarah went to plant her garden the following year, she decided that she wanted more colors of four o'clock than just pink. She decided that she wanted 25% red flowers, 25% white flowers and 50% pink flowers.
What genes must the parent plants have to produce offspring in these percentages?

Answer 1

For the Four o'clock flower color:

1. Sarah's parent plants must have been RW x RW.
2. Matthew's parent plants must have been Pp x Pp.
3. Sarah's parent plants must be Rrw x Rrw.

What are these genes?

The petal color of four o'clocks is determined by incomplete dominance. Plants with RR genes have red flowers, plants with WW genes have white flowers, and plants with RW genes have pink flowers.

Sarah's four o'clock flowers were all pink because both parent plants had RW genes.

Matthew's four o'clock flowers were 50% white and 50% pink because one parent plant had WW genes and the other parent plant had RW genes.

To get 25% red flowers, 25% white flowers, and 50% pink flowers, Sarah needs to cross two plants that are heterozygous for both red and white flower color, which means they have Rrw genes