Student Home Week 5: Quiz ×| quizlet genetic questions-,la Genetics Multiple Cho
ID: 197204 • Letter: S
Question
Student Home Week 5: Quiz ×| quizlet genetic questions-,la Genetics Multiple Choice Q| + v The Addams family has an autosomal dominant condition in which webbing attaches the second toe to the third toe and the second toe is longer than the wered big toe. Only some of the Addams' who inherit the mutant allele have a second toe longer than the big toe. In addition, the extent of webbing varies. This phenotype is t of Select one: estion O a. both inherited and non-inherited O b. dominant and recessive O C. invariably expressive and completely penetrant. O d. variably expressive and incompletely penetrant Hairlessness in dogs is inherited from a single dominant allele. Inheriting two dominant alleles is lethal for the embryo. Ralph and Penelope are both hairless swered dogs. What is the probability that Penelope will give birth to a hairy puppy? t of Select one: 0 a. 3/4 O b. 1/4 O c. 1/3 O d. 2/3 estionExplanation / Answer
Answer 1.
It is given that the condition is autosomal dominant. So, it can be inherited from parents to offspring; the condition is inherited. All heterozygous offsprings will have the condition. It is given that some Adams inherits the mutant allele also. So, option ‘a’ is incorrect.
The condition is not recessive, so, option ‘b’ is also incorrect.
The condition is not completely penetrant. Had it been completely penetrant, then all Adams who had inherited the mutant allele would have had the webbed toe with second toe larger than the third toe. So, option ‘c’ is also incorrect.
So, the correct answer is option d.
Answer 2.
It is given that presence of two dominant alleles is lethal. This means that Ralph and Penelope are heterozygous. Let the symbol for hairy be ‘H’ and non-hairy be ‘h’.
The probability of having a hairy puppy from two heterozygous parents will be:
The cross is: Hh X Hh
Result: 1 HH : 2 Hh : 1 hh
Probability of having hairy puppy is 3/4.
So, the correct answer is option ‘a’.