Zoology - Principles of Inheritance and Variation Question with Solution | TestHub

ZoologyPrinciples of Inheritance and VariationMonohybrid and Dihybrid CrossesEasy2 minPYQ_2020
ZoologyEasysingle choice

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:

PQR
1000 have inflated green pods242 constricted green pods 758 inflated green pods741 inflated green pod 259 inflated yellow pod



The correct genotypes of these three plants are

Options:

Answer:
C
Solution:

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 ratio1 : 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 ratio3 : 1. This is seen in plant Q

IIGg x IIGg will produce IIGG, IIGg and IIgg in the ratio1 : 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 ratio3 : 1. This is seen in plant R

Stream:NTA_ABHYAS_NEETSubject:ZoologyTopic:Principles of Inheritance and VariationSubtopic:Monohybrid and Dihybrid Crosses
⏱ 2mℹ️ Source: PYQ_2020

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