Questions 9-15 are related. The drosophila alleles for purpleeyes (instead of red) and dumpy wings (instead of normal) are bothrecessive. Gene âEâ designates eye color (E: dominant, e:recessive), and gene âDâ designates wing shape (D: dominant, d:recessive). You cross a pure breeding purple eyed, normal wingedfly to a true breeding red eyed, dumpy winged fly.
9. What are the genotypes of the parental flies? (select allthat apply)
EEDD
EEDd
EEdd
EeDD
EeDd
Eedd
eeDD
eeDd
eedd
10. What would you expect the offspring (F1) phenotypes tobe?
All purple eyed, dumpy winged
All red eyed, normal winged
All purple eyed, normal winged
All red eyed, dumpy winged
Half purple eyed normal winged, half red eyed dumpy winged
Half red eyed normal winged, half purple eyed dumpy winged
None of the above
11. You cross these F1 offspring to flies that are pure breedingfor purple eyes and dumpy wings. You get 200 offspring. 45 arepurple eyed and dumpy winged, 43 are red eyed and normal winged, 63are purple eyed and normal winged, and 49 are red eyed and dumpywinged. You think that these two genes could be on differentchromosomes but your friend tells you that he thinks they arelinked and that they are close enough to each other to have afrequency of recombinants of 0.38. If you are correct and they areon different chromosomes, how many purple eyed, normal winged flieswould you ideally expect out of your 200 offspring? Youranswer should be a whole number.
12. If your friend is correct and the genes are linked withfrequency of recombinants of 0.38 how many purple eyed, normalwinged flies would you expect? Your answer should be awhole number
Questions 9-15 are related. The drosophila alleles for purpleeyes (instead of red) and dumpy wings (instead of normal) are bothrecessive. Gene âEâ designates eye color (E: dominant, e:recessive), and gene âDâ designates wing shape (D: dominant, d:recessive). You cross a pure breeding purple eyed, normal wingedfly to a true breeding red eyed, dumpy winged fly.
9. What are the genotypes of the parental flies? (select allthat apply)
| EEDD |
| EEDd |
| EEdd |
| EeDD |
| EeDd |
| Eedd |
| eeDD |
| eeDd |
| eedd 10. What would you expect the offspring (F1) phenotypes tobe?
|
Related textbook solutions
Related questions
Please show detailed work. Thanks in advance.
16. Syntenic genes can assort independently when
A) they are very close together on a chromosome.
B) they are located on different chromosomes.
C) crossing over occurs rarely between the genes.
D) they are far apart on a chromosome and crossing over occurs frequently between the genes.
E) they are far apart on a chromosome and crossing over occurs very rarely between the genes.
17. The alleles of linked genes tend to
A) segregate together more often than expected by random assortment
B) assort independently.
C) be mutated more often than unlinked genes.
D) experience a higher rate of crossing over.
E) assort independently and show a higher rate of crossing over.
18. If you know that the frequency of recombination between genes X and Y is 34% and between X and Z is 25%, can you predict the order of the three genes?
A) Yes; the order is X-Z-Y.
B) Yes; the order is X-Y-Z.
C) Yes; the order is Z-X-Y.
D) No; based on this data alone, the order could be Z-Y-X or X-Y-Z.
E) No; based on this data alone, the order could be X-Z-Y or Z-X-Y.
Question 19 - 20. You have performed the following dihybrid cross in Drosophila using the black body color (b) and vestigial wing (vg) mutations. The b+ (grey body) and vg+ (normal wing) are dominant wild type alleles. These genes are autosomal.
Female â b+ vg+/b vg à male â b vg/b vg
Progeny:
Phenotype # of Progeny
Grey body normal wing 965
Black body vestigial wing 944
Grey body vestigial wing 208
Black body normal wing 195
19. Assuming linkage between black and vestigial, the estimated recombination frequency would be:
0.17
0.09
0.82
1.00
0.50
20. What key test could you use to determine whether the observed offspring frequencies deviate from those expected by chance alone?
A) Pascal's triangle
B) The product rule
C) The Chi-square (Ï2) test
D) The law of random assortment
E) The sum rule
21. In a genome wide association study (GWAS) designed to map the gene(s) that control height you divide subjects into a group of 1000 who are all more than seven feet tall and a control group of 1000 people of average height. You find the following associations between two genetic markers and the height trait:
| Tall group | Control group | ||
| Marker 1 | Allele A | 20% | 50% |
| Allele T | 80% | 50% | |
| Marker 2 | Allele G | 15% | 15% |
| Allele C | 85% | 85% |
What is your best guess for which marker is more closely linked to a gene that influences height?
A) Marker 1
B) Marker 2
22. Two pure breeding parents produce red and white flowers. They are crossed and the F1 produces pink flowers. When the F1 are selfed to produce the F2, nine distinct classes of pigmentation are present among F2 individuals. What is your best guess of the minimum number of genes that underlie flower pigmentation in this species?
A. 2
B. 3
C. 4
D. 5
E. 6
23. In a quantitative genetic experiment you identify two genes that confer bands of color on the back of a fly. At each gene, a dominant allele causes one band of color. If flies that are heterozygous at both loci are crossed, what ratio of offspring do you expect in each phenotype (i.e., number of color bands) class? (answer options are given from lowest to highest band number)
A) 1:1:1:1:1
B) 1:2:2:2:1
C) 1:4:6:4:1
D) 4:4:4:4:4
