New solution updates
Margaret E. Vorndam, M.S. Version 42-006100-01
LAB REPORT ASSISTANT
This document is not meant to be a substitute for a formal laboratory report. The Lab
Report Assistant is simply a summary of the experiments questions, diagrams if
needed, and data tables that should be addressed in a formal lab report. The intent is to
facilitate students writing of lab reports by providing this information in an editable file
which can be sent to an instructor.
Data Table 1: Punnett Square for F1 Cross Expected Genetic
F1 Parent, genes
(student to fill in the
Parent, g e n e s
(student fill in blank)
Data Table 2: Results of F1 Cross
Observed Phenotypes of F2 Progeny
# green plants =
Petri Dish 1 >
Petri Dish 2 >
# white plants =
Total # plants
Data Table 3: Dihybrid Cross in Corn Results of P Cross
P = purple, p = yellow
S = smooth, s = wrinkled
(student to fill in all blanks
dominant x recessive
F1 Progeny >
Data Table 3A: Punnett Square for F1 Dihybrid Cross
Expected Genotypic Outcomes
(student to fill in)
Parent 1 F1 can produce these gametes
(student to fill in)
Parent 2 F1 can
produce these gametes
Shaded portion above represents the F2
genotype and phenotype. Student to fill in.
Data Table 4: Dihybrid Cross in Corn Results of F1 Cross in F2
Predicted Allelic this
(Expected Ratio) Counted
* Actual Allelic Frequency (Observed Ratio)
= Number of this Phenotype Total Counted 100 kernels total counted
Data Table 5: 2 Goodness of Fit Test for F Phenotypic Results from F Corn
** [Observed No.
c2, Chi Sum
* Expected Number, calculated
= Sum of Observed Number x Expected Ratio for that phenotype
** = (Observed number Expected number, calculated) square
*** c, Chi-square value = Sum of (Observed number Expected number, calculated)
Expected Number, calculated
Data Table 6: Summarization of c2 Good Fit Results for F Corn Cross
c2 value from Table 5 =
Value at 3 Degrees of Freedom that is closest
What is the Fit Probability at the top of the
column in which the value was found?
What is the % of probability that the
observed results match the expected
(Multiply Fit Probability by 100)
Reading at the top of the Table, this Fit
Probability indicates that the expected
results hypothesis is a
Circle the correct choice above
Exercise 1: F1 Hybrid Cross
A. Expected phenotypic ratio of green to white progeny: Calculation of Expected Ratio
= Total Number of (Color) Seedlings Total of All Seedlings.
B. If 320 F2 offspring resulted from this F1 cross, how many would be green?
A. Did the results support or refute the hypothesis? Explain.
B. How similar are the observed to the expected results from the Punnett Square?
C. If the results are not similar, how might the difference be explained?
D. Will a monohybrid F1 cross in corn yield the same ratio of expected phenotype in
progeny as for the tobacco seedlings? Why or why not?
E. If available, compare your F2 seedling data to those of your classmates. Are the
outcome ratios the same? Why might using a larger number of seedlings to determine
this outcome be wise?
Exercise 2: Dihybrid Genetic Crosses
1. Based on what you can conclude about its genetic makeup when told that the corn
plant parent cross (P) pictured in Figure 2 is between a completely dominant plant
and a completely recessive plant
Construct and record a hypothesis about what the genetic makeup and the
frequencies of the alleles for the F1 progeny plants in the dihybrid cross of corn
will be. Record your hypothesis here
b. If these F1 progeny are mated, what will be the resulting allelic frequency for the F2
progeny? Record this hypothesis here
A. What are the two hypotheses that you made about the allelic frequencies of progeny
produced by the crosses
P x P?
F1 x F1?
B. Based on what you know about phenotypes and Figure 2, for the P
generation, what is the corn plant genotype on each cob containing the
P corn kernels? One is completely dominant, so its genotype is
One is completely recessive, so its genotype is.
C. Would it make a difference in the outcome of this cross if the genotype of one
parent is PPss and the other is ppSS?
D. From the phenotype of the kernels on each P generation cob what would the
predicted genotype of any F1 plant be?
E. Given the 2n equation predict how many different genetic outcomes will be possible
F1 cross resulting in the F2 generation in a dihybrid corn
F. If a F2 corn cob resulting from this F1 cross contained 563 seeds, how many of the
seeds would you expect to look like the F1 parent?
A. How well do the predicted results match the actual results in Table 4?
B. Based on the Punnett Square predictions, can a statement be made as to
whether your hypotheses are supported or rejected? Which and why?
C. Dihybrid F1 crosses result in a predictable F2 progeny phenotypic frequency that
holds true universally. Based on the Expected outcome, what is it?
D. If your results are not as expected why might there be differences?
E. What applications might this type of genetic investigation have? How might the
information be applied medically?
Exercise 3: Chi-square and Hypothesis Testing
A. What can be concluded about your prediction of expected F2 progeny phenotypic
outcome from the F1 cross? Was it close to the observed outcome?
B. How might the c2 test for fitness be used in other ways? Try it on the tobacco seedling F
cross, for instance.
C. In a typical cross where a parent with a completely dominant trait is mated with a
parent exhibiting a completely recessive trait, what is the expected genotypic outcome
and allelic frequency for the F1 progeny?
D. In a typical cross where hybrid F1 parents are mated, what is the expected genotypic
outcome and allelic frequency of the F2 progeny?
E. For the F2 progeny produced from a typical F1 hybrid mating, how many totally
recessive individuals would be produced if the progeny total population is six offspring?
What if the progeny population was 20?
F. Excluding factors such as sex-linked genes, incomplete dominance or epistasis
etc., will the above cross results vary if different organisms are used, such as dogs or
tulips? Why or why not?
G. How will factors such as sex-linked genes, incomplete dominance, or epistasis, etc.
affect the expected outcomes that were investigated above?
Solution ID:350765 | This paper was updated on 26-Nov-2015Price : $60