Question

a cactus can either have long needles (l) or short needles (l). a cactus grower crosses two cacti. the cross is shown in the punnett square below. what is the phenotype ratio for this cross? a. one long, three short b. four long, zero short c. three long, one short d. two long, two short

Explanation:

Step1: Determine dominant - recessive

Assume L is dominant for long needles and l is recessive for short needles.

Step2: Analyze genotypes in Punnett - square

The genotypes in the Punnett - square are LL, Ll, Ll, ll.

Step3: Determine phenotypes

LL and Ll show the long - needle phenotype, and ll shows the short - needle phenotype. So there are 3 long - needle (LL + Ll+Ll) and 1 short - needle (ll) cacti.

Answer:

C. Three long, one short