To cross-check your answer to the last question in the video, please click the link below.
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Table of contents:
00:00 - Forked line method Introduction
00.25 - Dihybrid cross in pea plant taken from NCERT textbook
01:11 - F1 Generation
01:50 - Finding phenotypic ratio through forked line method/ Branch line method in Genetics
05:17 - Finding genotypic ratio using forked line/branching line diagram in Genetics
03:37 - Application of multiplication rule in probability in Biology
07:36 - Comparision of phenotypic and genotypic ratios of the F2 generation
08:31 - Solving few problems in Genetics (Example problems)
11:39 - Another dihybrid cross in Pisum sativum. (practice question)
This video explains the process of writing the forked line method (also called branching diagram in genetics) in a dihybrid cross to find phenotypic and genotypic ratios. This time-saving method helps in predicting ratios accurately. These tricks can be used by students preparing for NEET exam (Medical aspirants) or anyone appearing for competitive exams to choose correct options without writing the entire cross.
The example of the genetic cross is adapted from the NCERT textbook, to focus learning on the method instead of example organism. I have given the link for the textbook below for students who haven't heard about the NCERT textbook and want to refer to it. (The book is free to access but should not be republished).
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Refer to chapter 5 - Principles of inheritance and variation; 5.3 - Inheritance of two genes.
There are few example questions mentioned in the video to teach the application of the method. Those are basic level questions. After learning, it is advised to practice some difficult questions for a clear understanding of the concept. If you are comfortable practicing different questions in trihybrid crosses, please follow the first link given below.
Link for trihybrid cross genotypic ratio and practice questions :
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Link for trihybrid cross phenotypic, genotypic ratios, and practice questions :
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Link for trihybrid example cross for practicing forked line method :
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References:
1. NCERT Class 12 textbook
2. Genetics 3rd Ed - Monroe W. Strickberger
Image Credits :
1. Pixabay
2. Naga Swetha ( Images are subject to copyright)
