Join the Most Relevant JEE Main 2025 Test Series & get 99+ percentile! Join Now
Search any question & find its solution
Question: Answered & Verified by Expert
Three pea plants P, Q and R each having inflated green pods are allowed to grow under natural conditions. 1000 seeds from each plant were collected and there were sown to see the properties of their progenies. The following were the observations:
 
P Q R
1000 have inflated green pods 242 constricted green pods 758 inflated green pods 741 inflated green pod 259 inflated yellow pod


The correct genotypes of these three plants are
BiologyPrinciples of Inheritance and VariationNEET
Options:
  • A P  IIGG, Q  IiGg, R  IIGg
  • B P  IIgg, Q  IiGG, R  IiGg
  • C P  IIGG, Q  IiGG, R  IIGg
  • D P  IIgg, Q  Iigg, R  IIGg
Solution:
2136 Upvotes Verified Answer
The correct answer is: P  IIGG, Q  IiGG, R  IIGg
Inflated pods are dominant in pea while constricted pods are recessive. Green pods are dominant in pea while yellow pods are recessive. All three plants have inflated green pods. So they should have one of the following genotypes IIGG, IiGG, IIGg or IiGg. These plants were grown naturally it means that there was self pollination.

IIGG x IIGG will produce all plants which are inflated and green. This is seen in plant P.

IiGG x IiGG will produce IIGG, IiGG and iiGG in the ratio 1 : 2 : 1 . Out of these IIGG and IiGG have inflated green pods while iiGG has constricted green pods. Thus Inflated green pods and Constricted green pods are produced in the ratio 3 : 1 . This is seen in plant Q

IIGg x IIGg will produce IIGG, IIGg and IIgg in the ratio 1 : 2 : 1 . Out of these IIGG and IIGg have inflated green pods while IIgg has inflated yellow pods. Thus Inflated green pods and inflated yellow pods are produced in the ratio 3 : 1 . This is seen in plant R

Looking for more such questions to practice?

Download the MARKS App - The ultimate prep app for IIT JEE & NEET with chapter-wise PYQs, revision notes, formula sheets, custom tests & much more.