Two human disorders, Prader-Willi syndrome and Angelman syndrome, occur when a small deletion in a specific region of chromosome 15 is contributed by either the father or mother, respectively. Why does this small deletion not behave as a recessive allele for either syndrome, that is, why is its loss not made up for by the good copy of the region on chromosome 15 contributed by the other parent?

#Question id: 4768

#Unit 8. Inheritance Biology

A trait that appears to be dominant in one sex but recessive in the other is called:

#Question id: 4785

#Unit 8. Inheritance Biology

One form of white eye is a recessive X-linked gene in Drosophila. From a mating of a heterozygous wild-type Drosophila female with a white-eyed male, what is the probability of wild type offspring?

#Question id: 4791

#Unit 8. Inheritance Biology

Body color in mice, YY is a recessive lethal, Yy yellow, yy gray and hair type straight is dominant over fuzzy. A geneticist crosses two yellow mice with heterozygous straight hair. Which the observe ratio is of obtains following progeny?

#Question id: 4794

#Unit 8. Inheritance Biology

 Following statement given for a character

A- Characteristics are determined by autosomal genes

B- Inherited according to Mendel’s principles

C-they are different expressivity in males and females

Which of the following having above statements feature?

#Question id: 4797

#Unit 8. Inheritance Biology

Non allelic genotype aa governing white phenotype with recessive epistatic over non allelic gene B for red phenotype Which of the following cross would produce 25 % white phenotype in their offspring? 

#Question id: 4725

#Unit 8. Inheritance Biology

Ptosis (droopy eyelid) may be inherited as a dominant human trait. Among 30 people who are heterozygous for the ptosis allele, 10 have ptosis and 20 have normal eyelids. What is the penetrance for ptosis?