You are studying a new strain of E. coli that can utilize the disaccharide melibiose very efficiently. You find that utilization depends on the enzyme melibiase, which is encoded by the gene Mel1. Mel1 is not expressed unless melibiose is present in the growth medium. Explain the two regulatory pathways for Mel1 that can explain the behavior of the MelA– and MelB– mutations. For each regulatory pathways what is a role for the inducer melibiose?

#Question id: 4757

#Unit 8. Inheritance Biology

The newborn baby of a mother having blood group O, Rh+ and father having blood group AB, Rh-, got mixed with other babies in the hospital. The baby with which of the following blood groups is not confirmable to be of the said couple?

(i) AB, Rh+                                                    (ii) O, Rh+

(iii) A, Rh+                                         (iv)  B, Rh+

#Question id: 4758

#Unit 8. Inheritance Biology

The allele l in human population is recessive lethal and x chromosome linked. If a female is heterozygous for l allele marries with normal male. What will be interpretation correct?

#Question id: 4759

#Unit 8. Inheritance Biology

which of the following is not a mechanism for sex determination?

#Question id: 4760

#Unit 8. Inheritance Biology

you set up a cross between true breeding wild type male fruit flies and true breeding female flies with a yellow body color. you notice in the f1 generation that half the flies, specifically all the males, have yellow body color while the females are wild type (gray). which of the following explanations is the most likely?

#Question id: 4761

#Unit 8. Inheritance Biology

which of the following statements about a lethal allele is not correct?

#Question id: 4762

#Unit 8. Inheritance Biology

a semilethal allele is an example of which of the following extensions of mendelian genetics?