Principle Of Inheritance And Variation Question 568
Question: A pure breeding pea plant with the dominant phenotype of character A and recessive phenotype of character B was crossed with another pure breeding plant with the recessive phenotype of A and dominant phenotype of character B. A offspring of this cross was crossed with a homozygous recessive for both the characters - A and B. The following results are obtained 22 were phenotypically dominant for A and recessive for B. 4 were phenotypically dominant for both A and B. 4 were phenotypically recessive for both A and B. 24 were phenotypically recessive for A and dominant for B. These results show that
Options:
A) Genes A and B are linked
B) Independent segregation of genes A and B
C) Mendelian dihybrid inheritance
D) Polygenic inheritance
Show Answer
Answer:
Correct Answer: A
Solution:
In this type of parents have the genotypes AAbb and aaBB, when they are crossed the offsprings with the genotype AaBb produced.
This offspring is crossed with the individual having the genotype aabb.
If the genes A and B show independent assortment, then the four types of offspring will be produced in the ratio 1 : 1 : 1 : 1.
But this does not happen, hence the genes A and B are linked.
BETA
