Download Biology 1408 - General Biology I Practice genetic problems for 3rd

Biology 1408 - General Biology I
Practice genetic problems for 3rd Laboratory Examination
In humans a dominant gene (R) is responsible for the ability to role the tongue, the inability to role the tongue is
due to the recessive allele (r).
If an individual who is RR is married to an rr individual:
1. phenotypic ratio of offspring is ________________________________
2. genotypic ratio of offspring is _________________________________
If an Rr individual is married to a rr individual:
3. phenotypic ratio of offspring is _________________________________
4. genotypic ratio of offspring is _________________________________
If two heterozygous individuals are married:
5. phenotypic ratio of offspring is __________________________________
6. genotypic ratio of offspring is __________________________________
Albinism, the total lack of pigment, is due to a recessive gene. A man and woman plan to marry and wish to know
the probability of their having any albino children. What is probability of albino children if:
7. both have normal pigmentation but each has one albino parent_________
8. the man is an albino, the woman is normal, but her father is an albino _________________.
9. the man is an albino and the woman is homozygous normal______________
10. If two parents with normal pigmentation have an albino child, what is the probability that if they have two
more children one will be an albino and the other have normal pigmentation _____________________
In guinea pigs B = black hair
b = white hair
L = long hair
l = short hair
Assume both pair of genes to be on separate chromosomes pairs, i.e. the genes are segregating in an independent
fashion and solve the following problems.
BbLL X bbLL
11. phenotypic ratio is __________________________
12. genotypic ratio is ____________________________
BbLl x bbLl
13. phenotypic ratio is ___________________________
14. genotypic ratio is ___________________________
BbLl X bbll
15. phenotypic ratio is ___________________________
16. genotypic ratio is ___________________________
BbLl X BbLl
Solve this cross by the genotypic method.
17. Show set up of genotypic method with a Punnet square in space below.
18. phenotypic ratio _______________________________________________
19. genotypic ratio ________________________________________________
20. Give all gamete types of an AaBbDd individual if all three alleles are on separate chromosome pairs.
____________________________________________________________________
In humans, gene R = + blood and its recessive allele r = - blood.
An independent set of genes determines the A,B,O blood types.
If an A- women heterozygous for A marries a B+ man heterozygous for both blood groups, give all possible
phenotypes of the children.
21. _______________________________________________________________
_______________________________________________________________
If the dominant allele H is necessary for hearing and the dominant allele M of another independent gene results in
deafness no matter what other genes are present.
22. What percentage of the offspring produced by the
cross hhMm X Hhmm will be deaf ___________________
23. If DdEeFfGgHh is crossed to DdEeFfGgHh, what would be the predicted frequency of ddEEFfggHh offspring
from such a mating? ________________
In humans C = normal vision and c = color blindness. This gene pair is sex linked. Solve the following problems
based upon the above data.
A normal vision woman whose father was color blind marries a normal vision man.
24. Give phenotypic ratio of sons ______________________________________
25. Give genotypic ratio of sons ______________________________________
26. Give phenotypic ratio of daughters ___________________________________
27. Give genotypic ratio of daughters ___________________________________
If an individual with blood type AB is married to a heterozygous B individual,
28. the probability of children with A is ______________________________
29. the probability of children with B is ______________________________
30. the probability of children with O is ______________________________
31. the probability of children with AB is _____________________________
In fruit flies of the genus Drosophila
G = gray bodies
g = black bodies
L = long wings
l = vestigial wings
These two gene pairs are linked, i.e. present on the same chromosome but with a certain amount of crossing over.
If GgLl is crossed to ggll, the following offspring were obtained:
gray, long flies = 118
black, vestigial = 122
gray, vestigial = 32
black, long
= 28
32. What is map distance between these two gene pairs _______________
Use the nearest even number from the above answer to set up a cross
of GgLl X GgLl.
33. Set up this cross in the space below with the correct gametes on the edge of the Punnett square.
Frequency of gray, long flies ____________
Frequency of black, vestigial flies ___________
Frequency of gray, vestigial flies ___________
Frequency of black, long flies ______________
If alleles Aa and Bb are linked with 6% crossing over. An animal with the genotype AaBb (A and B on the same
chromosome) would produce what percent of the following gamete types?
34.
AB __________
35.
Ab ____________
36.
aB ____________
37.
ab _____________
In rabbits
S = spotted body color
H = short hair
s = solid body color
h = long hair
When rabbits heterozygous for both characteristics were mated with
homozygous recessive rabbits, the following offspring were produced:
spotted, short hair
solid, short hair
spotted, long hair
solid, long hair
96
14
10
80
38. what is evidence for linkage ________________________________
39. give percentage of recombination between the genes ____________
40. What is chromosome makeup of heterozygous parent. Choose 1,2, or 3 from below:
______________________
1. *
S
s
*
*
*
*
*
2.* *
s s
3* *
S s
*
*
*
*
* *
* *
H
h
h
h
h H
*
*
R
*
*
R
*
*
R
*
*
R
* *
* *
R R
41. What is chromosome makeup of homozygous parents. Choose 1,2, or 3 from the above list
_____________________
42. If the above genes were not linked and assorting independently, what would be the frequency of each
phenotype ________________
If a cross of Aa to aa gives 45 Aa and 55 aa and we predict a 1 Aa :
1 aa ratio. Use the chi-square test to determine if 45 Aa and 55 aa
is close enough to be 1 : 1 ratio.
Aa genotype
aa genotype
100
Observed values
45
Expected values
43. ___________
44. ____________
Deviations (d)
45. ___________
46. _____________
Deviations squared
47. ___________
48. _____________
49.___________
50. _____________
d2 / e
55
Total__100_________
51.
chi-square value = __________________
52.
Is this chi-square value significiant or non-significant (circle one).
53.
Based upon the X2 value, is 45 Aa and 55 aa close enough to be a 1 : 1 ratio? Explain.