× Didn't find what you were looking for? Ask a question
Top Posters
Since Sunday
a
5
k
5
c
5
B
5
l
5
C
4
s
4
a
4
t
4
i
4
r
4
r
4
New Topic  
nhutnibo nhutnibo
wrote...
Posts: 1
Rep: 0 0
10 years ago
A pure-breeding white mouse with a long tail was crossed to pure-breeding pink mouse with a short tail. The F1 progeny were all pink with long tails. These F1 mice were test crossed to white mouse with a short tail.

If the gene controlling colour and the gene controlling tail length in mice are very closely linked, what phenotypes are expected to be the most frequent in the progeny of the test cross?
      

A)Pink, short tail and white, short tail
B)Pink, short tail and white, long tail
C)Pink, long tail and white, long tail
D)Pink, long tail and white, short tail
E)There is not enough information to make a prediction
Read 5790 times
1 Reply

Related Topics

Replies
wrote...
Donated
Valued Member
10 years ago
Given the results of the F1 cross, it can be determined that Pink and Long are the dominant traits (since purebred white x purebred pink = pink and purebred long x purebred short = long)

This dictates the parental genotypes and F1 cross as:

(white/long) ppLL x PPll (pink/short)
All F1 offspring are PpLl genotype (heterozygous pink and heterozygous long)
Purebred white, purebred short are ppll's, so the next cross is:
PpLl x ppll

When genes are linked, the parental genotypes are the most frequent progeny:
PpLl (Pink with Long Tail) &
ppll (White with Short Tail)

Answer choice D)
Pretty fly for a SciGuy
New Topic      
Explore
Post your homework questions and get free online help from our incredible volunteers
  1293 People Browsing
 111 Signed Up Today
Related Images
  
 165
  
 2471
  
 751
Your Opinion
What's your favorite math subject?
Votes: 293