1. Genetics QUIZ

3. GENETIC CORN LAB

4. Carolina Biological 1: Pollination
Carolina Biological 1: Pollination FILE
Carolina Biological: 2 Harvesting
Carolina Biological: 2 Harvesting FILE
Carolina Biologica: 3 Preparing the seeds
Carolina Biologica: 3 Preparing the seeds - FILE

5. Where do seeds come from?
Tassel (flower with pollen)
Silk (flower with eggs)

9. Describe the corn plants – at least three facts.
Ask at least one question.
Write two characteristics – one inherited, one that is not.
Two traits? Phenotypes? 6.Letters?
Which phenotypes are recessive and which – dominant? Explain.
7. COUNT each phenotype. Ratio.
8. Compare to Mendel’s predictions.

10. Trait 1:
Trait 2:
Phenotype 1:
Phenotype 2:
Number of plants:
Ratio:

12. Chlorophyll A
Chlorophyll-binding protein

15. Dwarf
Normal
No GA effect
GA effect
Gibberrelinic acid
(GA)

16. Answer questions 1-8, including your counts.
LAB:
Answer questions 1-8, including your counts.

17. Describe the corn plants – at least three facts.
Ask at least one question.
Write two characteristics – one inherited, one that is not.
Two traits? Phenotypes? 6.Letters?
Which phenotypes are recessive and which – dominant? Explain.
7. COUNT each phenotype. Ratio.
8. Compare to Mendel’s predictions.

18. Journal:
Two Tall Green corn plants were crossed, giving rise to the seeds we had planted.
Looking at the seedlings, what must be the genotypes of the parents? (Choose the letters)
What would be the expected phenotypic ratio in the children?
Explain.

19. For each trait, the phenotypic ratio isG g GG Gg gg
G - Green
g - White
T – Tall,
t – Dwarf
Green: White
¾ : ¼
For each trait, the phenotypic ratio is
¾ : ¼ T t TT Tt tt
Tall: Dwarf
¾ : ¼
Is this what your counts show?

20. NOTES

21. Notes: Mendel’s Law of Independent Assortment
Looking at two traits at a time
“Allele pairs separate independently of each other during gamete formation by meiosis.”
When does this law work?
Only when the genes are situated on different chromosomes (not linked)

22. Assort Independently: A and C; B and C Do NOT assort Independently:
A and B - they are on the same chromosome.
This will affect the ratios between the phenotypes in F2 generation…

23. Are the two genes, for color and for height sitting on the same chromosome?
If they are NOT, and they assort independently, then we can allow ourselves to:
List ALL the possible gamete combinations in the punnet sq.
Multiply individual probabilities.

24. GgTt x GgTt
G - Green
g - White
T – Tall,
t – Dwarf
Possible phenotype Combinations:
Green, Tall
Green, Dwarf
White, Tall
White, Dwarf
If the two traits are inherited independently, what are their expected ratios?

25. A. PUNNET SQUARE

26. G = Green, g = White plant
T = Tall, t = Dwarf
For Corn….
GgTt x GgTt
All the possible gametes: GT Gt gT gt GT
Step 2: Placing gametes in the punnet square Gt gT gt
For the following crosses, List the possible gametes of each parent. Then draw the punnet square for the two traits.
YySs x YySs
YYss x YySS

27. YySs x YySs
What is the expected phenotypic outcome? GT Gt gT gt
GgTT
GgTt
GGTt
GGTT GT
GgTt
GGtt
Ggtt
GGTs Gt
ggTT
ggTt
GgTt
GgTT gT
ggTt gt
Ggtt
ggtt
GgTt
For the following crosses, List the possible gametes of each parent. Then draw the punnet square for the two traits.
YySs x YySs
YYss x YySS

28. Expected phenotypic outcome:
Green
Tall
Green
Dwarf
White
Tall
White
Dwarf
9/16 :
3/16 :
3/16 :
1/16
Now, compare these predictions to your actual counts!

29. B. MULTIPLYING PROBABILITIES

30. For each trait, the phenotypic ratio is ¾ : ¼G g GG Gg gg
G - Green
g - White
T – Tall,
t – Dwarf
Green: White
¾ : ¼
For each trait, the phenotypic ratio is ¾ : ¼ T t TT Tt tt
Tall: Dwarf
¾ : ¼
Is this what your counts show?

31. Are the probabilities of the combined phenotypes, the products of the individual chances?9
¾ x ¾ = 9/16
Green, Tall
Green, Dwarf
White, Tall
White, Dwarf 3
¾ x ¼ = 3/16
¼ x ¾ = 3/16 3
¼ x ¼ = 1/16 1
Is this what we got in our counts?

32. Expected phenotypic outcome:
Green
Tall
Green
Dwarf
White
Tall
White
Dwarf
9/16 :
3/16 :
3/16 :
1/16
Now, compare these predictions to your actual counts!

33. Write the possible gametes in the following parent: AaBbCc (notice: one allele per gamete for each genes: ABC, Abc, …)
2. Repeat your answer considering the position of the genes on the chromosomes:

34. Assort Independently: A and C; B and C Do NOT assort Independently:
A and B - they are on the same chromosome.
This will affect the ratios between the phenotypes in F2 generation…

35. Assignment: Answer ALL question in the packet up to 15.
For extra 40 points – continue to question 19!
(For number 12 – draw the chart, calculate the ratios, by turning the largest count into 9, and dividing the rest by the same factor).

36. ACTUAL COUNTS?

37. Draw the following chart for the F2 generation, count the plants and fill in the numbers you got:
Green
Tall
Dwarf
White

38. Draw the following chart for the F2 generation, count the plants and fill in the numbers you got (2 classes):
Green
Tall
Dwarf
White 82 27 30 4
/ 9.11=
/ 9.11 = 9

39. Complete Lab – Part TWO
Part THREE, looking at the REAL gene mapping on the corn chromosomes, can be done at home, for extra credit!