Answers to Practice Examination 4:
A. Multiple Choice:
1. b
2. d
3. false
4. e
5. d
6. a
7. e
8. b
9. b
10. a
11. b
12. c
13. a
14. d
15. c
16. e
17. d
18. b
19. e
20. c
B. Matching. See text and notes
C. Short Problems
1a)
This complementation mapping experiment defines 4 different loci;
mutations 1,3, 4 and 7 lie in the same cistron
mutations 5, 8 and 10 lie in the same cistron
mutations 6, and 9 lie in the same cistron
mutation 2 represents a single isolate for this cistron
1b)
mutant 7 would not complement mutant 3
mutant 4 would complement mutant 9
mutant 9 would complement mutant 10
2a)
Gene T; it is observed in only ½ of the gametes
2b)
Gene T; same reason as above
2c)
Genes Q, R and S are autosomal since this individual is heterozygous for two different
loci. Gene locus S is not closely linked to Q and R on the basis of this data since the
alleles representing these loci appear to assort independently.
2d)
Genes Q and R appear to be linked, since the Q1 and Q2 alleles do not assort
independently relative to R1 and R2. On the basis of this data, the Q and R loci are 5 map
units apart.