Question

8. Two heterozygous purple flowered plants are crossed.

Answer 1

Answer:

75% chance of purple, 25% of white

Explanation:

Heterozygous means having two different alleles of a gene

This must mean they are Purple dominant and white recessive

This will be represented as Pw

$\left[\begin{array}{ccc} &P&w\\P&PP&Pw\\w&Pw&ww\end{array}\right]$

This, called a punnet square, calculates the probability of the gene outcome. The top Pw represents one parent and the Pw on the left side represent the other.

In the diagram, each combo of letters ( PP, Pw, Pw, ww ) represents a 25% of what gene the offspring will have. PP  means it'll be purple, and so does both Pw's. ww means white flowers though because there is no dominant trait and only recessive. This is the only way for a recessive trait to appear in a child.

Therefore there is a 75% chance of the offspring having purple flowers and a 25% chance of the offspring have white flowers.