assignment for BIO 350 Human Biology Week 7 Genetic Inheritance

GeneticInheritance
Margaret E. Vorndam,
M.S.Version 42-0061-00-01

LAB REPORTASSISTANT

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for
aformallaboratoryreport.TheLabReport Assistantissimplyasummaryoftheexperiment’squestions,diagramsifneeded,anddatatables
that
shouldbeaddressedinaformallabreport.
Theintentistofacilitatestudents’writing
oflab reports by providing
this informationin an editable
filewhich can be sent to an instructor.

Data Table
1: PunnettSquare for F1 Cross – Expected GeneticOutcomes

F1Parent,
genes: (student to
fillin the blanks)

alleles >
alleles v

F1 Parent,
genes:__________(student fill
in blank)

Data Table
2: Results of F1 Cross

Observed Phenotypes of F2Progeny

# green plants =

# white plants
=

Total # plants

Petri Dish 1 >

Petri Dish 2 >

Total

.gif”>.gif”>.gif”>

Data
Table 3: Dihybrid Cross in Corn
– Results of P Cross

P = purple, p = yellow
S = smooth, s = wrinkled
(student
to fillin all blanks )

Generation

Expected Alleles

Expected Alleles

P >
dominant x recessive

_ppss_

F1Progeny
>

Frequency >

Data
Table 3A: PunnettSquare for
F1 Dihybrid Cross

Expected Genotypic Outcomes
(student to fill
in)

Parent 1 F1– can produce
these gametes: (student to
fillin)

Parent2F1 –canproduce
these gametes:
>

ShadedportionaboverepresentstheF2progeny
genotype and phenotype.Student to fill
in.

.gif”>

Data
Table 4: Dihybrid Cross in Corn
– Results of F1 Cross in F2 Progeny

Phenotype of
Progeny

(What they
look like – word
description)

Genetic Designations possible for
this Phenotype

e.g., PPSS

Predicted Allelic
Frequency

(Expected Ratio)

Number
of this Phenotype Total Counted:

100 (Observed
Number)

Actual Allelic
Frequency

(Observed
Ratio)*

e.g., Yellow,
wrinkled

ppss

* Actual Allelic Frequency (Observed Ratio)
=
Number of this PhenotypeTotal
Counted ¸ 100 kernels total counted

Data Table 5: ?2Goodness of Fit Test for F Phenotypic Results from F Corn
Cross
2 1

Phenotype
Description
of F2Progeny
from Table 4

Observed Number from Table 4

Observed Ratio
from Table 4

Expected Ratio
from Table 4

*
Expected Number, calculated

** [Observed No. – Exp. No.]2
÷ Expected No.

e.g., Yellow,
wrinkled

? Sum
of column =

c2,Chi-square value ***
>

* Expected
Number, calculated
= ? Sum of Observed Number x Expected Ratiofor
that phenotype
** = (Observed
number – Expected number, calculated)
square
÷
Expected Number, calculated
***
c2,Chi-squarevalue=?Sumof(Observednumber–Expectednumber,calculated)
squared ÷
Expected Number, calculated

Data Table 6: Summarizationofc2 Good
Fit Results for F Corn Cross
1

c2 value from Table
5 =

Value at 3 Degrees
of Freedom that is closest toc2
value =

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
results?
(MultiplyFit Probability
by 100)

Reading at
the top of the Table, this Fit Probability indicates that
the expected results hypothesis is a

Good
Fit Poor Fit

Circle the correct choice above

Exercise
1: F1 Hybrid Cross

A. Expectedphenotypicratioofgreentowhiteprogeny: CalculationofExpectedRatio
(Frequency) = = Total Number of (Color) Seedlings ÷ Total
of All Seedlings.

B. If 320 F2offspringresulted
from this F1cross, how many would
be green?

White?

DISCUSSION

A. Did the results support or refute the hypothesis?
Explain.

B. How
similar are the observed to
the expected results from the PunnettSquare?

C. If the results are not
similar, how might the differencebe explained?

D. WillamonohybridF1crossincornyieldthesameratioofexpectedphenotype
inprogenyas
for the tobacco seedlings? Why or why
not?

E. Ifavailable,
compareyourF2seedlingdatatothoseofyourclassmates.Aretheoutcomeratios the same? Why might using a larger
number of seedlings to determine
this outcome be wise?

Exercise
2: Dihybrid GeneticCrosses
PROCEDURE

1.
Basedonwhatyoucanconcludeaboutitsgeneticmakeupwhentoldthatthecornplant parentcross(P)picturedinFigure2isbetweenacompletelydominantplantandacompletely recessive plant,

a. Constructandrecordahypothesis
aboutwhatthegeneticmakeupandthefrequencies oftheallelesfortheF1 progenyplantsinthedihybridcrossofcornwillbe.Recordyour
hypothesis here:

b.
IftheseF1
progenyaremated,whatwillbetheresultingallelic
frequencyfortheF2
progeny?
Record this hypothesis
here:

RESULTS

A. Whatarethetwohypothesesthatyoumadeabouttheallelicfrequenciesofprogenyproduced by
the crosses:

P x P?

F1x 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. WoulditmakeadifferenceintheoutcomeofthiscrossifthegenotypeofoneparentisPPss and the other is ppSS?

D. FromthephenotypeofthekernelsoneachPgeneration cobwhatwouldthepredicted
genotype of any F1plant
be?

E. Giventhe2nequationpredicthowmanydifferentgeneticoutcomeswillbepossiblefroman
F1cross
resultingin the F2generationin
a dihybrid corn cross.

F. IfaF2corncobresultingfromthisF1crosscontained563seeds,howmanyoftheseeds
would you expect to look like
the F1parent?

QUESTIONS

A. How well do the predicted
results match the actual results in Table 4?

B. Based
onthePunnettSquarepredictions,canastatementbemadeastowhetheryour hypotheses
are supported or rejected? Which and why?

C. DihybridF1
crossesresultinapredictableF2
progenyphenotypicfrequencythatholdstrue
universally. Based on the
Expected outcome, what is it?

D. If your results
are not as expected why might
there be differences?

E. Whatapplicationsmightthistypeofgeneticinvestigationhave?Howmighttheinformation
be applied medically?

Exercise
3: Chi-square and Hypothesis Testing
QUESTIONS

A. Whatcanbeconcludedaboutyourprediction
ofexpectedF2
progenyphenotypicoutcome from
the F1cross? Was
it close to the observed outcome?

1

B. Howmightthec2testforfitnessbeusedinotherways?Tryitonthetobaccoseedling
F
cross, for
instance.

C. Inatypicalcrosswhereaparentwithacompletelydominanttraitismatedwithaparent
exhibiting acompletelyrecessivetrait,whatistheexpectedgenotypicoutcomeandallelic frequency
for the F1progeny?

Give an example.

D. InatypicalcrosswherehybridF1parentsaremated,whatistheexpectedgenotypic
outcome and allelic frequency
of the F2progeny?

Give an example.

E. FortheF2 progenyproducedfromatypicalF1 hybridmating,howmanytotallyrecessive individuals would be produced if
the progeny total
populationis six offspring?

What if the progeny
populationwas 20?

50?

1,000?

F. Excluding
factorssuchassex-linkedgenes,incompletedominance
orepistasis,etc.,willthe above cross
results vary if differentorganisms
are used, such as dogs or tulips? Why or why
not?

G. Howwillfactorssuchassex-linked genes,incompletedominance,orepistasis,
etc.,affectthe
expected outcomes that
were
investigatedabove?