Question

Question 5 (14 marks) The allele cn gives fruit flies cinnabar eyes, whereas the allele cn gives red, the wild-type phenotypeWrite the full genotype of the female trihybrid used in the testcross using proper notation and gene order. (2 marks) f Were

0 0
Add a comment Improve this question Transcribed image text
Answer #1

Answer:

a&b).

Question 5 (14 marks) The allele cn gives fruit flies cinnabar eyes, whereas the allele cn gives red, the wild-type phenotype

c).

Hint: Non-recombinant (parental) combinations are produced more in number than recombinants. The parental (non-recombinant) genotypes is b+ cn+ wx / b cn wx+ (brown body, red eyes, non-waxy wings)

1).

If single crossover occurs between b&cn

Normal combination: b+ cn+ / b cn

After crossover b+ cn / b cn+

b+ cn progeny=112+5 = 117

v+ cv+ progeny = 109+3=112

Total this progeny = 229

Total progeny = 1163

The recombination frequency between b&cn = (number of recombinants/Total progeny) 100

RF = (229/1163)100 = 19.69%

2).

If single crossover occurs between cn&wx

Normal combination: cn+ wx / cn wx+

After crossover: cn+ wx+ / cn wx

cn+ wx+ progeny= 109+52= 161

cn wx progeny = 112+48= 160

Total this progeny = 321

The recombination frequency between cn&wx = (number of recombinants/Total progeny) 100

RF = (321/1163)100 = 27.60%

3).

If single crossover occurs between cn&wx

Normal combination: b+ wx / b wx+

After crossover: b+ wx+ / b wx

b+ wx+ progeny= 5+52= 57

b wx progeny = 3+48= 51

Total this progeny = 108

The recombination frequency between b&wx = (number of recombinants/Total progeny) 100

RF = (108/1163)100 = 9.29%

Recombination frequency (%) = Distance between the genes (mu)

cn--------19.69mu------b----9.29mu----wx

The order of genes = cn –b--wx

d). cn--------19.69mu------b----9.29mu----wx

e). Trihybrid genotype = cn+ -----b+-----wx / cn ----b-----wx+

f). b & cn are in cis linkage

Add a comment
Know the answer?
Add Answer to:
Question 5 (14 marks) The allele cn gives fruit flies cinnabar eyes, whereas the allele cn...
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Not the answer you're looking for? Ask your own homework help question. Our experts will answer your question WITHIN MINUTES for Free.
Similar Homework Help Questions
  • 2. The allele b gives Drosophila flies a black body, and bt gives brown, the wild-type...

    2. The allele b gives Drosophila flies a black body, and bt gives brown, the wild-type phenotype. The allele wx of a separate gene gives waxy wings, and wx+ gives nonwaxy, the wild-type phenotype. The allele cn of a third gene gives cinnabar eyes, and cn* gives red, the wild-type phenotype. A female heterozygous for these three genes is testcrossed, and 1000 progeny are classified as follows: 5 wild type, 6 black waxy cinnabar, 69 waxy cinnabar, 67 black, 382...

  • Questions 10 and 11 please (10.-11.) The allele b gives Drosophila flies a black body and...

    Questions 10 and 11 please (10.-11.) The allele b gives Drosophila flies a black body and bt gives brown, the wild-type phenotype. The allele wx of a separate gene gives waxy wings and wx+ gives non-waxy, the wild-type phenotype. The allele cn of a third gene gives cinnabar eyes and cnt gives red, the wild-type phenotype. A female heterozygous for these three genes is testcrossed, and 1000 progeny are classified as follows: 382 cinnabar 379 black, waxy 69 waxy, cinnabar...

  • Can you please help me with this problem: 3. The allele b gives Drosophila flies a...

    Can you please help me with this problem: 3. The allele b gives Drosophila flies a black body, and b+ gives brown, the wild type phenotype. The allele wx of a separate gene gives waxy wings, and wx+ gives nonwaxy, the wild type phenotype. The allele cn of a third gene gives cinnabar eyes, and cn+ gives red, the wild-type phenotype. A female heterozygous for these three genes is testcrossed, and 1000 progeny are classified as follows: 5 wild type;...

  • For Questions 15-18 The allele b gives Drosophila a black body, and b gives brown (the...

    For Questions 15-18 The allele b gives Drosophila a black body, and b gives brown (the wildtype). The allele wx of a second gene gives waxy wings and wx* gives nonwaxy wings (the wildtype). The allele cn of a third gene gives cinnabar eyes and cnt gives red (the wildtype). A female heterozygous for these three genes is testcrossed and 1000 progeny are classified as follows: bt, wx, cn 382 b, wx, en 379 bt, wx, cn 69 b, wx,...

  • A new gene is being investigated in fruit flies. The recessive allele of this gene (b)...

    A new gene is being investigated in fruit flies. The recessive allele of this gene (b) causes the wings to develop a blue color, while the dominant allele (b) permits wild-type colorless wings to develop. Preliminary studies indicate that this new gene is located on the X-chromosome. You decided to perform a two-point testcross to determine its position relative to the well-established garnet eyes gene (g). You cross a female heterozygous for both genes with a testcross male fly, and...

  • For Questions 15-18 The allele b gives Drosophila a black body, and b+ gives brown (the...

    For Questions 15-18 The allele b gives Drosophila a black body, and b+ gives brown (the wildtype). The allele wx of a second gene gives waxy wings and wx* gives nonwaxy wings (the wildtype). The allele en of a third gene gives cinnabar eyes and cngives red (the wildtype). A female heterozygous for these three genes is testcrossed and 1000 progeny are classified as followst b, wx, en 389 b, wx, en 379 bt, wx, cn b, wx, en 67...

  • In fruit flies, the gene mutations cinnabar (cn, bright red eyes), curved (c, curved wings), and...

    In fruit flies, the gene mutations cinnabar (cn, bright red eyes), curved (c, curved wings), and plexus (px, extra wing veins) are linked on the second chromosome. A triple heterozygous female was used in a test cross and the following progeny were counted. What is the distance between the genes for cinnabar and curved? cinnabar, curved, plexus 296 curved, plexus 63 plexus 119 cinnabar, plexus 10 cinnabar, curved 86 curved 15 wildtype 329 cinnabar 82

  • In Drosophila (fruit flies) the genes how, dumpy and ebony are located on chromosome 3. LOF...

    In Drosophila (fruit flies) the genes how, dumpy and ebony are located on chromosome 3. LOF = loss of function. Flies homozygous for a LOF mutation (no gene product made) in ebony have dark black bodies. Flies homozygous for a LOF mutation (no gene product made) in dumpyhave truncated (short) wings. Flies homozygous for a partial LOF mutation (some gene product made but significantly less than normal) in how have wings that will not fold down (held out wings; that's...

  • In Drosophila, the autosomal recessive traits for dumpy wings (dp) and cinnabar eyes (cn) are found...

    In Drosophila, the autosomal recessive traits for dumpy wings (dp) and cinnabar eyes (cn) are found on chromosome 2, separated by 44 map units. The allele for shaven bristles (sv) is found on chromosome 4 and is also recessive. A female with shaven. bristles is crossed to a male expressing dumpy wings and cinnabar eyes. FI females are test-crossed to males expressing all three traits. 3. What proportion of F2 flies (of either sex) will be completely wild type? a....

  • In Drosophila (fruit flies) the genes how, dumpy and ebony are located on chromosome 3. LOF...

    In Drosophila (fruit flies) the genes how, dumpy and ebony are located on chromosome 3. LOF = loss of function. Flies homozygous for a LOF mutation (no gene product made) in ebony have dark black bodies. Flies homozygous for a LOF mutation (no gene product made) in dumpy have truncated (short) wings. Flies homozygous for a partial LOF mutation (some gene product made but significantly less than normal) in how have wings that will not fold down (held out wings;...

ADVERTISEMENT
Free Homework Help App
Download From Google Play
Scan Your Homework
to Get Instant Free Answers
Need Online Homework Help?
Ask a Question
Get Answers For Free
Most questions answered within 3 hours.
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT