MENDELLIAN GENETICS LAB Click on a box to begin. SCIENCE 10 LIFE SCIENCES: GENETICS PART A Analyzing...
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Transcript of MENDELLIAN GENETICS LAB Click on a box to begin. SCIENCE 10 LIFE SCIENCES: GENETICS PART A Analyzing...
MENDELLIAN GENETICS LAB
Click on a box to begin.
SCIENCE 10 LIFE SCIENCES: GENETICS
PART AAnalyzing results
PART BPredicting results
PART CExplaining results
PART DExperimental design
Genome British Columbia, 2004 www.genomicseducation.ca
PART A: COMPLETE DOMINANCE
INTRODUCTION:
You’re back in 1865 and Gregor Mendel is getting ready to publish his results. Being a good scientist, he wants to check that his results are repeatable. You’ve just been hired by Mendel to study the heredity of two traits:
1. seed color: green or yellow
2. seed shape: smooth or wrinkled
yellow, winkled
green,
smoothyellow,
smooth
OBJECTIVE:
Mendel gives you three plants that produce the following seeds:
He asks you to breed new plants to determine the genotypes of these plants.
PROCEDURE:Click on the plants that you would like to cross.
self-fertilize
self-fertilize
self-fertilize
cross-fertilize
cross-fertilize
cross-fertilize
Click here when you have finished collecting all your data.
You need to select the plants that you want to
cross to see the data.
Click anywhere on this screen to go back.
You need to select the plants that you want to
cross to see the data.
Click anywhere on this screen to go back.
DATA:
Click anywhere on this screen to go back.Remember to record this data in your data table.
self-fertilized
Click anywhere on this screen to continue.
DATA: self-fertilized
Click anywhere on this screen to go back.Remember to record this data in your data table.
Click anywhere on this screen to continue.
DATA:
self-fertilized
Click anywhere on this screen to go back.Remember to record this data in your data table.
Click anywhere on this screen to continue.
DATA:
Click anywhere on this screen to go back.Remember to record this data in your data table.
cross-fertilized
Click anywhere on this screen to continue.
DATA:
Click anywhere on this screen to go back.Remember to record this data in your data table.
cross-fertilized
Click anywhere on this screen to continue.
DATA:
Click anywhere on this screen to go back.Remember to record this data in your data table.
cross-fertilized
Click anywhere on this screen to continue.
What is the dominant allele for seed color?
ANALYSIS:
YELLOW GREEN
What is the dominant allele for seed color?
ANALYSIS:
YELLOW GREEN
Yellow
What is the dominant allele for seed color?
ANALYSIS:
YELLOW GREEN
Yellow
It is the more common color.A dominant allele always covers a recessive allele.
What is the recessive allele for seed shape?
ANALYSIS:
SMOOTH WRINKLED
What is the recessive allele for seed shape?
ANALYSIS:
SMOOTH
Wrinkled
WRINKLED
What is the recessive allele for seed shape?
ANALYSIS:
SMOOTH
Wrinkled
It is the less common shape.A recessive allele is always covered by a dominant allele.
WRINKLED
CONCLUSION:
If we use “Y” for yellow color & “S” for smooth shape. What is the genotype of the plant that produces the yellow, wrinkled seeds?A. YYSS C. YySsB. YYss D. Yyss
CONCLUSION:
If we use “Y” for yellow color & “S” for smooth shape. What is the genotype of the plant that produces the yellow, wrinkled seeds?A. YYSS C. YySsB. YYss D. Yyss
Hint: A self-fertilized parent that produces offspring with the identical traits must be homozygous for both traits.
CONCLUSION:
If we use “Y” for yellow color & “S” for smooth shape. What is the genotype of the plant that produces the yellow, wrinkled seeds?A. YYSS C. YySsB. YYss D. Yyss
Hint: A self-fertilized parent that produces offspring with the identical traits must be homozygous for both traits.
B. YYss
Ys Ys Ys Ys
YsYYss YYss YYss YYss
YsYYss YYss YYss YYss
YsYYss YYss YYss YYss
YsYYss YYss YYss YYss
self-fertilized
CONCLUSION:
If we use “Y” for yellow color & “S” for smooth shape. What is the genotype of the plant that produces the green, smooth seeds?A. YySS C. yySSB. YySs D. yySs
CONCLUSION:
If we use “Y” for yellow color & “S” for smooth shape. What is the genotype of the plant that produces the green, smooth seeds?A. YySS C. yySSB. YySs D. yySs
C. yySS
yS yS yS yS
ySyySS yySS yySS yySS
ySyySS yySS yySS yySS
ySyySS yySS yySS yySS
ySyySS yySS yySS yySS
self-fertilized
CONCLUSION:
If we use “Y” for yellow color & “S” for smooth shape. What is the genotype of the plant that produces the yellow, smooth seeds?A. YySs C. YYSsB. YySS D. YYSS
CONCLUSION:
If we use “Y” for yellow color & “S” for smooth shape. What is the genotype of the plant that produces the yellow, smooth seeds?A. YySs C. YYSsB. YySS D. YYSS
A. YySs
YS Ys yS ys
YSYYSS YYSs YySS YySs
YsYYSs YYss YySs Yyss
ySYySS YySs yySS yySs
ysYySs Yyss yySs yyss
self-fertilized
PART B: COMPLETE DOMINANCE (cont.)
INTRODUCTION:
Before giving Mendel your results from Part A, you decide to verify your results by self-fertilizing certain F1 offspring.
OBJECTIVES:
For the following crosses, predict the genotypes and phenotype ratios for the F2 offspring.
self-fertilized
?
YYss yySS
?
yySS YySs
self-fertilized
YySs YYss
self-fertilized
?For each cross, predict the genotype and phenotype ratio, then click on that box to see the expected results.
PROCEDURE:
YS Ys yS ys
YSYYSS YYSs YySS YySs
YsYYSs YYss YySs Yyss
ySYySS YySs yySS yySs
ysYySs Yyss yySs yyss
YySs YySs
Phenotype ratio:
RESULTS:
YS Ys yS ys
YSYYSS YYSs YySS YySs
YsYYSs YYss YySs Yyss
ySYySS YySs yySS yySs
ysYySs Yyss yySs yyss
YySs YySs
Phenotype ratio:
9 yellow, smooth
3 yellow, wrinkled
3 green, smooth
1 green, wrinkled
RESULTS:
yS yS yS yS
ySyySS yySS yySS yySS
ySyySS yySS yySS yySS
ySyySS yySS yySS yySS
ySyySS yySS yySS yySS
If homozygous, then phenotype ratio:
RESULTS: yySS yySS
yS yS yS yS
ySyySS yySS yySS yySS
ySyySS yySS yySS yySS
ySyySS yySS yySS yySS
ySyySS yySS yySS yySS
If homozygous, then phenotype ratio:
all green, smooth
RESULTS: yySS yySS
yS yS yS yS
ySyySS yySS yySS yySS
ySyySS yySS yySS yySS
ySyySS yySS yySS yySS
ySyySS yySS yySS yySS
If homozygous, then phenotype ratio:
all green, smooth
or
If heterozygous, then phenotype ratio:
RESULTS: yySS yySS
yS yS ys ys
ySyySS yySS yySs yySs
ySyySS yySS yySs yySs
ysyySs yySs yyss yyss
ysyySs yySs yyss yyss
Phenotype ratio:
RESULTS: yySs yySs
yS yS ys ys
ySyySS yySS yySs yySs
ySyySS yySS yySs yySs
ysyySs yySs yyss yyss
ysyySs yySs yyss yyss
Phenotype ratio:
12 green, smooth
4 green, wrinkled
RESULTS: yySs yySs
Ys Ys Ys Ys
YsYYss YYss YYss YYss
YsYYss YYss YYss YYss
YsYYss YYss YYss YYss
YsYYss YYss YYss YYss
If homozygous, then phenotype ratio:
RESULTS:
YYss YYss
Ys Ys Ys Ys
YsYYss YYss YYss YYss
YsYYss YYss YYss YYss
YsYYss YYss YYss YYss
YsYYss YYss YYss YYss
If homozygous, then phenotype ratio:
all yellow, wrinkled
RESULTS:
YYss YYss
Ys Ys Ys Ys
YsYYss YYss YYss YYss
YsYYss YYss YYss YYss
YsYYss YYss YYss YYss
YsYYss YYss YYss YYss
If homozygous, then phenotype ratio:
all yellow, wrinkled
or
If heterozygous, then phenotype ratio:
RESULTS:
YYss YYss
Ys Ys ys ys
YsYYss YYss YYss YYss
YsYYss YYss YYss YYss
ysYYss YYss yyss yyss
ysYYss YYss yyss yyss
Phenotype ratio:
RESULTS:
Yyss Yyss
Ys Ys ys ys
YsYYss YYss YYss YYss
YsYYss YYss YYss YYss
ysYYss YYss yyss yyss
ysYYss YYss yyss yyss
Phenotype ratio:
12 yellow, wrinkled
4 green, wrinkled
RESULTS:
Yyss Yyss
PART C: INCOMPLETE DOMINANCE
INTRODUCTION:
Mendel is impressed with your intelligence and hard work, so he decides to gives you another project to work on.
OBJECTIVES:
Given the following data, explain the results.
self-fertilized
DATA:
ANALYSIS:
Phenotype ratios:
F1
F2
ANALYSIS:
Phenotype ratios:
F1 all medium
F2
ANALYSIS:
Phenotype ratios:
F1 all medium
F2 1 long : 2 medium : 1 short
ANALYSIS:
Phenotype ratios:
F1 all medium
F2 1 long : 2 medium : 1 short
Intermediate phenotype and phenotype ratios indicates incomplete dominance.
If we use “L” for long size & “l” for short size. Note: There is insufficient information to determine which allele is more dominant, so long size was arbitrarily chosen as dominant.
F1
If we use “L” for long size & “l” for short size. Note: There is insufficient information to determine which allele is more dominant, so long size was arbitrarily chosen as dominant.
F1 L L
l
l
L L l l
Phenotype ratio:
If we use “L” for long size & “l” for short size. Note: There is insufficient information to determine which allele is more dominant, so long size was arbitrarily chosen as dominant.
F1 L L
lLl Ll
lLl Ll
L L l l
Phenotype ratio:
If we use “L” for long size & “l” for short size. Note: There is insufficient information to determine which allele is more dominant, so long size was arbitrarily chosen as dominant.
F1 L L
lLl Ll
lLl Ll
LL l l
Phenotype ratio:
all medium
F2Phenotype ratio:
F2 L l
L
l
Phenotype ratio:
Ll Ll
F2 L l
LLL Ll
lLl l l
Phenotype ratio:
Ll Ll
F2 L l
LLL Ll
lLl l l
Phenotype ratio:
1 long
2 medium
1 short
Ll Ll
PART D: CODOMINANCE
INTRODUCTION:
Mendel’s results were not well received by other scientists. With his extensive experience in growing pea plants, he pursues a career in farming. He decides to selectively breed a new type of corn that produces sweeter, saltier kernels. He starts with one plant that produces sweeter kernels and another plant that produces saltier kernels.
He performs several crosses and successfully produces a plant with sweeter, saltier kernels but discovers that his phenotype ratios are not consistent with his pea plant results. After examining his results, you suspect codominance. However, Mendel is not yet familiar with this concept.
OBJECTIVE:
Assuming that Mendel started with purebreds, design an experiment that illustrates this concept to Mendel. Include a hypothesis.
SAMPLE EXPERIMENT
PROCEDURE:
1. Cross-fertilize parents with each other
2. Cross-fertilize F1 with each parent to verify parents are purebreds
3. Self-fertilize F1 offspring and compare ratios
4. Repeat
EXPECTED RESULTS:
Using: A = sweet, a = not sweetB = salty, b = not salty
If parent plants are purebreds, then:
Positive results for codominance:
F1: all sweet, salty (AB)
F2: 1 sweet, not salty (AA)2 sweet, salty (AB)1 not sweet, salty (BB)
Negative results for codominance:i.e. positive results for separate 2 traits
F1: all sweet, salty (AaBb)
F2: 9 sweet, salty(1 AABB, 2 AABb, 2 AaBB, 4 AaBb)
3 sweet, not salty (1 AAbb, 2 Aabb)3 not sweet, salty (1 aaBB, 2 aaBb)1 not sweet, not salty (aabb)