CCSIR NET 2024 | Life Science: Inheritance Biology | 29 March

LOD ("logarithm of the odds”) is a statistical measure of linkage. What does the LOD score of zero signify?

Which one of the following statement about maternal inheritance is false?

In X-linked inheritance, when a red-eyed female Drosophila is crossed with white-eyed male Drosophila, the resulting F1 progenies are all red-eyed. What is the probability of white-eye male (F2 generation) drosophila when a red-eyed male is crossed with a red-eyed female from the F1 generation?

A phenotypically normal fruit fly was crossed to another fly whose phenotype was not recorded. Of the progeny, 3/8 were wild type, 3/8 had ebony body color, 1/8 had vestigial wings and 1/8 had ebony body color and vestigial wings. Ebony body color and vestigial wings are recessive characters and their genes are located on two different autosomes. Based on this information which one of the following is the likely genotype of the parents?

A recessive inherited disease is expressed only in individuals of blood group O and not expressed in blood groups A, B or AB. Alleles controlling the disease and blood group are independently inherited. A normal woman with blood group A and her normal husband with blood group B already had one child with the disease. The woman is pregnant for second time. What is the probability that the second child will also have the disease?