1. PRACTICE

2. Probability is the that an event will occur; expressed as a .
chance
percentage

3. Example: White wool (W) is dominant; black wool (w) is recessive.ww WW Ww

4. White wool (W) is dominant; black wool (w) is recessive.
What is the probability of this cross producing offspring with black wool? WW Ww
Probabilities:
WW:
50%
Ww:
50% W W W w
ww: 0%
100%
White wool:
Black wool: 0% WW Ww WW Ww
White wool (W) is dominant; black wool (w) is recessive.

5. White wool (W) is dominant; black wool (w) is recessive.
What is the probability of this cross producing offspring with black wool? Ww Ww
Probabilities:
WW:
25%
Ww:
50% W w W w
ww:
25%
75%
White wool:
Black wool:
25% WW Ww Ww ww
White wool (W) is dominant; black wool (w) is recessive.

6. White wool (W) is dominant; black wool (w) is recessive.
What is the probability of this cross producing offspring with black wool? Ww ww
Probabilities:
WW: 0%
Ww:
50% W w w w
ww:
50%
50%
White wool:
Black wool:
50% Ww Ww ww ww
White wool (W) is dominant; black wool (w) is recessive.

7. White wool (W) is dominant; black wool (w) is recessive.
What is the probability of this cross producing offspring with wool? ww ww
Probabilities:
WW: 0%
Ww: 0% w w w w
ww:
100% 0%
White wool:
100%
Black wool: ww ww ww ww
White wool (W) is dominant; black wool (w) is recessive.

8. A can also be used to show the probable outcome of a genetic cross; used by geneticists to.
Punnett
square
make
predictions
gametes
Offspring

9. Example: Dimples (D) are dominant; no dimples (d) is recessive.DD Dd dd

10. Dimples (D) are dominant; no dimples (d) is recessive.
What is the probability that this couple will produce a child with dimples? Dd
Probabilities: Dd D d
DD:
25% D DD Dd
Dd:
50%
dd:
25%
Dimples:
75% d Dd dd
No dimples:
25%
Dimples (D) are dominant; no dimples (d) is recessive.

11. Dimples (D) are dominant; no dimples (d) is recessive.
What is the probability that this couple will produce a child with dimples? dd
Probabilities: Dd d d
DD: 0% D Dd Dd
Dd:
50%
dd:
50%
Dimples:
50% d dd dd
No dimples:
50%
Dimples (D) are dominant; no dimples (d) is recessive.

12. Dimples (D) are dominant; no dimples (d) is recessive.
If all of the offspring have dimples, what are this father’s alleles?
Probabilities: d d
DD: 0% D Dd Dd
Dd:
100%
dd: 0%
Dimples:
100% D Dd Dd
No dimples: 0%
Dimples (D) are dominant; no dimples (d) is recessive.

13. An organism’s genotype is its .
allele
combination
Tall
Tall
Short TT Tt tt

14. An organism’s phenotype is the way it .
looks
Tall
Tall
Short TT Tt tt

15. A B C What is the genotype of person B? Dimples No dimples Dimples dd

16. A B C What is the phenotype of person C? Dimples No dimples Dimples dd

17. A B C Which two people have the same phenotype? Dimples No dimplesdd DD Dd

18. Two organisms can have the , but.
same
phenotype
different
genotypes
Dimples
Dimples DD Dd

19. White wool (W) is dominant; black wool (w) is recessive.
What is the phenotype of sheep A?
Black wool X A B
White wool (W) is dominant; black wool (w) is recessive.

20. White wool (W) is dominant; black wool (w) is recessive.
What is the genotype of sheep A? Defend. ww
2 recessive alleles are needed to be expressed X A B
White wool (W) is dominant; black wool (w) is recessive.

21. White wool (W) is dominant; black wool (w) is recessive.
Can you tell the phenotype of sheep B just by looking at it?
Yes!
White wool X A B
White wool (W) is dominant; black wool (w) is recessive.

22. White wool (W) is dominant; black wool (w) is recessive.
What are two possible genotypes for sheep B? WW Ww X A B
White wool (W) is dominant; black wool (w) is recessive.

23. White wool (W) is dominant; black wool (w) is recessive.
Given the offspring produced by this cross, what is the
genotype of sheep B? Defend. Ww
Made black offspring X A B C D E F
White wool (W) is dominant; black wool (w) is recessive.

24. A homozygous genotype has the .
same
alleles TT Tt tt

25. A heterozygous genotype has .
different
alleles TT Tt tt

26. A B C Which person has a heterozygous genotype? Dimples No dimplesDD Dd dd

27. A B C What word describes person A and B? Homozygous Dimples
No dimples
Dimples DD Dd dd

28. A B C Which person is homozygous recessive? Dimples No dimples DimplesDD Dd dd

29. A B C Person A is . homozygous dominant Dimples No dimples Dimples DD

30. Dimples = D; no dimples = d
To have a , the genotype must be
recessive
phenotype
homozygous
No dimples dd
Dimples = D; no dimples = d

31. Dimples = D; no dimples = d
Construct a Punnett square showing a cross between a man who is homozygous dominant and a woman who is heterozygous.
Probabilities: D d
DD:
50% D DD Dd
Dd:
50%
dd: 0%
Dimples:
100% D DD Dd
No dimples: 0%
Dimples = D; no dimples = d

32. Plants A and C have the same .
phenotype A C B tt Tt TT

33. Plants A and B are both
homozygous A C B tt Tt TT

34. Plant A is
homozygous
dominant A C B tt Tt TT

35. Which of these could NOT be the offspring of TT X Tt parents?

36. Which of these could NOT be the offspring of Tt X tt parents?

37. Identify the eye that could be homozygous dominant.

38. Identify the eye that could be heterozygous.

39. Eye B has to be
homozygous
recessive A B

40. Which of these eyes could result from a BB x Bb cross?

41. In Mendel’s experiment, which generations contained a homozygous recessive plant?F1 F2 TT tt Tt Tt Tt Tt TT Tt Tt tt

42. In Mendel’s experiment, which generations contained heterozygous plants?. P F1 F2 TT tt Tt Tt Tt Tt TT Tt Tt tt

43. State the phenotype of the F1 generation.
Tall P F1 F2 TT tt Tt Tt Tt Tt TT Tt Tt tt

44. What percent of the F2 generation is heterozygous?TT tt Tt Tt Tt Tt TT Tt Tt tt
50%

45. What percent of the F1 generation is heterozygous?TT tt Tt Tt Tt Tt TT Tt Tt tt
100%

46. What percent of the P generation is heterozygous?TT tt Tt Tt Tt Tt TT Tt Tt tt
0%s

47. Genetics Problem #3: Black Parents, White Baby
Dark skin (D) is dominant; light skin (d) is recessive

48. Create a Punnett square showing how this type of inheritance is possible.
Probabilities: D d
DD:
25%
Dd:
50% D DD Dd
dd:
25%
Dark:
75% d Dd dd
Light:
25%

49. 45. If this couple decides to have another baby, what is the probability that the baby will have light skin?
46. If this couple decides to have another baby, what is the probability that the baby will have dark skin?
47. If this couple decides to have another baby, what is the probability that the baby will be a carrier?
25%
75%
50%