Question

a purple flower with an unknown genotype is crossed with a white flower how do you determine the genotype if hte purple flower if purple is dominant and white is recessive?

Answer 1

Captial P would represent Dominant for the purple flower. Since the White flower is recessive use lower case w

Answer 2

Dominant is always capitalized and recessive is always lower case so if you have Dd then its dominant since the first letter is dominant,if its yy then its recessive.you can also look at the punnet squares.

Answer 3

By convention, genes are named for the recessive trait. So the letter representing plant color would be w for "white". The lower case "w" indicates the recessive/white allele, while upper case "W" indicates the dominant/purple allele. Takes some getting used to - but if they were two different letters, everyone would think they corresponded to two different genes instead of variants of the same gene.

The white plant in the cross has two recessive w alleles. The purple plant can be either homozygous dominant WW or heterozygous Ww for the color gene. Crossing a plant with a dominant phenotype but unknown genotype with a homozygous recessive organism is called a test cross.

Angelbaby is correct: you should draw Punnett Squares for the possible crosses WW x ww and Ww x ww.