Question

Consider a cross to investigate the pea pod ure trait, involving constricted or inflated pods. Mendel found that the traits behave according to a dominant/recessive pattern in which inflated pods were dominant. If you performed this cross and obtained 650 inflated-pod plants in the F₁ generation, approximately how many constricted-pod plants would you expect to have?

a) 650
b) 325
c) 975
d) 1300

Answer 1

According to Mendelian genetics and a dominant/recessive trait pattern, if 650 inflated-pod plants are observed in the F2 generation, approximately 217 constricted-pod plants would be expected, based on a 3:1 phenotype ratio.

the closest option is:

b) 325

Step-by-step explanation:

When investigating the pea pod texture trait which includes constricted or inflated pods and following Mendelian genetics, there is a dominant/recessive pattern where the inflated pod trait is dominant. If a cross is performed and 650 inflated-pod plants are observed in the F2 generation, then according to the Mendelian laws of inheritance, you would expect to see a phenotype ratio of 3:1 for the inflated (dominant):constricted (recessive) traits. Thus, for every 3 inflated pods, there should be approximately 1 constricted pod.

Therefore, if there are 650 inflated-pod plants, you would expect approximately 650 / 3 = 217 constricted-pod plants.