Lab Report: Gene Mapping Answer the questions below. When you are finished, submit this assignment to your teacher by the due date for full credit.
For all questions, assume that you have genes for beak color, tail-feather length, and feather color all linked (located) on the same chromosome, but you don't know the order of the genes on the chromosome or the distance between them. The alleles for these genes are
beak color: Y for yellow beak (YY and Yy) and y for black beak (yy)
tail-feather length: L for long tail (LL and Ll) and l for short tail (ll)
feather color: B for blue feathers (BB and Bb) and b for white feathers (bb)
Total score: Click or tap here to enter text. of 22 points
Part 1: Crossing Beak Color and Tail-Feather Length
Cross a YyLl (heterozygous parent with dominant traits) with yyll (h-o-m-o-zygous parent with recessive traits). Look at the number of genotypes of the F1 generation:
YyLl: 400
Yyll: 100
yyLl: 100
yyll: 400
(Score for Question 1: Click or tap here to enter text. of 2 points)
Which offspring are the recombinant offspring in this cross?

Yyll and yyLl
(Score for Question 2: Click or tap here to enter text. of 2 points)
How far apart are Y and L? Give your answer in map units. (Hint: Add the numbers of the two recombinant types, divide by the total number of offspring, and multiply by 100.)

200/1000*100=20 map units. There is a 20 percent recombinant offspring frequency.

Part 2: Crossing Beak Color and Feather Color
Cross beak color and feather color.
(Score for Question 1: Click or tap here to enter text. of 2 points)
Cross one parent that is heterozygous for both beak color and feather color with a parent that is h-o-m-o-zygous for both recessive traits. What are the genotypes of the parents? (Hint: Recall that the P generation includes a heterozygous parent with dominant traits and a h-o-m-o-zygous parent with recessive traits.)
Assume the following F1 generation:
YyBb: 420
Yybb: 80
yyBb: 80
yybb: 420

YyBB420
YyBb420
(Score for Question 2: Click or tap here to enter text. of 2 points)
Which offspring are the recombinant offspring in this cross?


(Score for Question 3: Click or tap here to enter text. of 2 points)
How far apart are Y and B?


Part 3: Crossing Tail-Feather Length and Feather Color
Cross a P generation, LlBb with llbb. Assume the following F1 generation:
LlBb: 480
Llbb: 20
llBb: 20
llbb: 480
(Score for Question 1: Click or tap here to enter text. of 2 points)
Which offspring are not the recombinant offspring in this cross?

LlBb and llBb
(Score for Question 2: Click or tap here to enter text. of 2 points)
How far apart are L and B?

L and B are 4 units apart because they make up 4 % of the total recombinant types.

Part 4: Mapping Beak Color, Tail-Feather Length, and Feather Color
Now you are ready to figure out the order of the genes for beak color, tail-feather length, and feather color on the chromosome and build a genetic map.
(Score for Question 1: Click or tap here to enter text. of 2 points)
List the distances between each pair of genes:
beak color and tail-feather length:
beak color and feather color:
tail-feather length and feather color:

Type your answer here.
(Score for Question 2: Click or tap here to enter text. of 2 points)
Which two alleles are the farthest apart?

Type your answer here
(Score for Question 3: Click or tap here to enter text. of 2 points)
Which two alleles are the closest together?

Type your answer here.
(Score for Question 4: Click or tap here to enter text. of 2 points)
True or False: The diagram shows the correct genetic map for these three alleles on one chromosome.


Type your answer here.