Question

in a cross of purple flowered heterozygous plants (pp), the letter p represents the allele for purple flowers and the letter p represents the allele for white flowers.
what is the probability that an offspring of this cross expresses plants with purple flower phenotypes?
a. 0
b. $\frac{1}{4}$
c. $\frac{1}{2}$
d. $\frac{3}{4}$

Explanation:

Step1: Create Punnett square for Pp × Pp

	$P$	$p$
$p$	$Pp$	$pp$

Step2: Identify purple phenotypes

Purple flowers are expressed by genotypes with at least one dominant $P$ allele: $PP$, $Pp$, $Pp$.

Step3: Calculate probability

Probability = $\frac{\text{Number of purple phenotypes}}{\text{Total number of offspring}} = \frac{3}{4}$

Answer:

D. 3/4