1) You perform a 3pt testcross and find one of your double crossover offspring classes is Abc and one of your parental classes is abc. You find that the RF for ab is 15% and the RF for bc is 30%. What is the distance between genes A and C?
2)You cross LM/lm à lm/lm individuals and find 30% of your offspring are lM/lm. How far apart are your genes. What proportion of the offspring should be lm/lm?In humans, the genes for red-green color blindness (R = normal, r = color-blind) and hemophilia A (H = normal, h = hemophilia) are both X-linked and 5 map units apart.
3)Suppose a woman has 15 sons, and 7 are colorblind with haemophilia, 7 are phenotypically normal, and one has hemophilia but normal color vision. Show the genotypes of her offspring. What is the chromosomal arrangement of alleles of the woman?
4)Waxy endosperm (wx), shrunken endosperm (sh), and yellow seedling (v) are encoded by three recessive genes in corn that are linked on chromosome 5. The F1 from an unknown true breeding parental cross is then crossed with a plant homozygous for the recessive genes. Following are the progeny of the testcross. What is the order of the genes and the distance between the genes?
wx sh V 1400
Wx Sh v 1500
Wx Sh V 3500
wx sh v 3400
Wx sh V 292
wx Sh v 280
wx Sh V 90
Wx sh v 80
1) You perform a 3pt testcross and find one of your double crossover offspring classes is Abc and one of your parental classes is abc. You find that the RF for ab is 15% and the RF for bc is 30%. What is the distance between genes A and C?
2)You cross LM/lm à lm/lm individuals and find 30% of your offspring are lM/lm. How far apart are your genes. What proportion of the offspring should be lm/lm?In humans, the genes for red-green color blindness (R = normal, r = color-blind) and hemophilia A (H = normal, h = hemophilia) are both X-linked and 5 map units apart.
3)Suppose a woman has 15 sons, and 7 are colorblind with haemophilia, 7 are phenotypically normal, and one has hemophilia but normal color vision. Show the genotypes of her offspring. What is the chromosomal arrangement of alleles of the woman?
4)Waxy endosperm (wx), shrunken endosperm (sh), and yellow seedling (v) are encoded by three recessive genes in corn that are linked on chromosome 5. The F1 from an unknown true breeding parental cross is then crossed with a plant homozygous for the recessive genes. Following are the progeny of the testcross. What is the order of the genes and the distance between the genes?
wx sh V 1400
Wx Sh v 1500
Wx Sh V 3500
wx sh v 3400
Wx sh V 292
wx Sh v 280
wx Sh V 90
Wx sh v 80
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
