Principle of Inheritance and VariationMediumBloom L3
Question
The ratio of 2 : 1 is observed in case of
Options
A.suppressor gene
B.dominant-recessive epistasis
C.complementary gene
D.lethal gene
Solution
Sol.(d) [Key Concept: Lethal Gene — 2:1 Ratio] A 2:1 phenotypic ratio in F2 is observed in case of LETHAL GENES. When the homozygous dominant condition (AA) is lethal (causes embryonic death), the expected 1:2:1 genotypic ratio becomes 1AA(dead):2Aa:1aa → only Aa and aa survive = 2:1 ratio among live offspring. Classic example: yellow coat colour in mice (AY allele — AY AY is lethal; AY a = yellow coat; aa = black coat → ratio 2 yellow:1 black among live mice).
Create a free account to view solution
View Solution FreeTopic: Principle of Inheritance and Variation·Practice all Principle of Inheritance and Variation questions
More Principle of Inheritance and Variation Questions
In snapdragon, when a red flower plant is crossed with a white flower ones, The resultant hybrid plant have pink coloure...Marriages between close relatives should be avoided because it includes more...Albinism is a congential disorder resulting from the lack of enzyme...Multiple alleles are present :...An organism with two identical alleles is called...