Scholars Biology 3 Genetics Lab Report Searching for Correlations Between Phenotypes

Scholars Biology 3Scholars Biology 3Genetics Lab ReportGenetics Lab Report

Searching for Correlations Searching for Correlations Between Phenotypes Between Phenotypes

Refer to your syllabus for a Refer to your syllabus for a more detailed description of more detailed description of

items to be included in the lab items to be included in the lab report.report.

Components of the Lab ReportComponents of the Lab Report

•PurposePurpose

•MethodsMethods

•ResultsResults

•DiscussionDiscussion

•Literature CitedLiterature Cited

PurposePurpose

•Describe why the experiment was Describe why the experiment was done done

•Identify the hypotheses being tested Identify the hypotheses being tested

----1 hypothesis for simple inheritance1 hypothesis for simple inheritance

--1 hypothesis for complex inheritance--1 hypothesis for complex inheritance

--2 hypotheses for taste perception--2 hypotheses for taste perception

Hypothesis for Hypothesis for Simple InheritanceSimple Inheritance

If the dominant and If the dominant and recessive alleles are recessive alleles are present in equal present in equal frequencies, this frequencies, this Punnett square Punnett square represents the ratio of represents the ratio of expected offspring for expected offspring for the whole population.the whole population.

EE

ee

E e E e

EEEE

EeEe

EeEe

eeee

75% free earlobes75% free earlobes25% attached earlobes25% attached earlobes

Choose any trait Choose any trait (EXCEPT short index finger) (EXCEPT short index finger)

and determine whether the alleles are and determine whether the alleles are present in equal frequencies. present in equal frequencies. (See p. 95 for details.)(See p. 95 for details.)

Hypothesis for Hypothesis for Complex InheritanceComplex Inheritance

Multigenic Traits often show a range of phenotypes Multigenic Traits often show a range of phenotypes that approaches a normal distribution for numbers that approaches a normal distribution for numbers of individuals with each phenotype.of individuals with each phenotype.

For our experiment: Determine whether we see a For our experiment: Determine whether we see a normal distribution of heights with different central normal distribution of heights with different central values for males and females. values for males and females.

Hypotheses for Hypotheses for Taste PerceptionTaste Perception

Determine whether there is a relationship Determine whether there is a relationship between between 1. 1. Supertaster and PTC-tasting phenotypes Supertaster and PTC-tasting phenotypes

2. Supertaster phenotypes and any ONE of the 2. Supertaster phenotypes and any ONE of the following: following: Gender Gender

Preference for Brussels sprouts Preference for Brussels sprouts Preference for Cheese Preference for Cheese Preference for Black coffee Preference for Black coffee Preference for Dark chocolate Preference for Dark chocolate

MethodsMethodsProvide a brief description of the techniques, Provide a brief description of the techniques, materials and/or equipment used in the materials and/or equipment used in the experiment. experiment. Emphasize how the methods accomplish Emphasize how the methods accomplish the purpose given in the previous section. the purpose given in the previous section. Focus on the determination of the Focus on the determination of the phenotypes that are represented in your phenotypes that are represented in your hypotheses, rather than all the traits tested. hypotheses, rather than all the traits tested. DO NOT write this section as a step-by-DO NOT write this section as a step-by- step guide for repeating the experiment. step guide for repeating the experiment. DO write it as a summary of the DO write it as a summary of the experimental procedure in past tense. experimental procedure in past tense.

ResultsResults

• Present your experimental data in this Present your experimental data in this section. section.

• Introduce the reader to the data with a brief Introduce the reader to the data with a brief description that refers to the content of description that refers to the content of specific figures or tables. specific figures or tables.

• Choose the most appropriate format for Choose the most appropriate format for each type of data presented. each type of data presented. – Simple Inheritance: Table or HistogramSimple Inheritance: Table or Histogram– Complex Inheritance: Line GraphComplex Inheritance: Line Graph– Taste Perception: Table or HistogramTaste Perception: Table or Histogram

ResultsResults• Essential elements of a Essential elements of a

line graph or histogramline graph or histogram– Put a label and specify the units on each axis Put a label and specify the units on each axis – Make the plotted points or bars clearly visibleMake the plotted points or bars clearly visible– Connect related points by a best-fit lineConnect related points by a best-fit line– Include a key to identify different lines, bars Include a key to identify different lines, bars – Provide a caption BENEATH the graph or Provide a caption BENEATH the graph or

histogramhistogram• Brief descriptionBrief description• TitleTitle

– Number consecutively from Figure 1Number consecutively from Figure 1

Graphing the Data for Complex InheritanceGraphing the Data for Complex InheritanceN

umbe

r of

Stu

dent

sN

umbe

r of

Stu

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s

Height (cm)Height (cm)

0123456789

Males

Females

Class

Male AverageMale Average

Female AverageFemale Average

Class AverageClass Average

Figure 1: Distribution of Heights in a Scholars’ Biology 3 Figure 1: Distribution of Heights in a Scholars’ Biology 3 Class During Fall Semester 2003. Heights of 25 students Class During Fall Semester 2003. Heights of 25 students were grouped into the size categories shown.were grouped into the size categories shown.

Displaying Data in a HistogramDisplaying Data in a Histogram

Per

cent

of

Stu

dent

sP

erce

nt o

f S

tude

nts

Figure 2: Frequency of Tongue-Rolling Trait in a Scholars’ Figure 2: Frequency of Tongue-Rolling Trait in a Scholars’ Biology 3 Class During Fall Semester 2003. Phenotypes of Biology 3 Class During Fall Semester 2003. Phenotypes of 25 students were determined by visual observation. 25 students were determined by visual observation.

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

1

Rolling

Can't Roll

Tongue-Rolling Phenotypes

ResultsResults

• Essential elements of a tableEssential elements of a table– Provide a caption ABOVE the tableProvide a caption ABOVE the table

• TitleTitle• Brief descriptionBrief description

– Present the data in clearly labeled Present the data in clearly labeled columns and rows columns and rows

– Provide labels and units of measure if Provide labels and units of measure if applicableapplicable

– Number consecutively from Table 1Number consecutively from Table 1

Displaying Data in a Table Displaying Data in a Table

Table 1: Frequency of Mid-Digital Hair in a Table 1: Frequency of Mid-Digital Hair in a Scholars’ Biology 3 Class During Fall Scholars’ Biology 3 Class During Fall Semester 2003. Phenotypes of 25 students Semester 2003. Phenotypes of 25 students were determined by visual observation. were determined by visual observation.

PhenotypePhenotype PercentagePercentage

Mid-digital HairMid-digital Hair 0.440.44

No Hairy DigitsNo Hairy Digits 0.560.56

Discussion Discussion Present your interpretation of the results in Present your interpretation of the results in

this section. this section. Draw conclusions that are based on the Draw conclusions that are based on the

experimental evidence. experimental evidence. Discuss whether or not the original Discuss whether or not the original

hypotheses were supported by the data. hypotheses were supported by the data. Explain any discrepancies in your data.Explain any discrepancies in your data. Elaborate on the biological implications of Elaborate on the biological implications of

the results.* the results.* Relate your results to existing scientific Relate your results to existing scientific

knowledge.*knowledge.* *See Dr. Colavito’s Other Links Web Page *See Dr. Colavito’s Other Links Web Page

for more information on Supertasters. for more information on Supertasters.

Literature CitedLiterature Cited

Include ONLY references cited in your Include ONLY references cited in your report. report.

To cite references in the text, use the To cite references in the text, use the format (Author, year).format (Author, year).

In the literature cited section, use the In the literature cited section, use the following format: following format: For journal: For journal: Author, year, Title, Journal Author, year, Title, Journal

Name, volume number and pages Name, volume number and pages For book: Author, year, Title, PublisherFor book: Author, year, Title, Publisher

and City of publication and City of publication For Web Page: URL and Date AccessedFor Web Page: URL and Date Accessed

Length of Length of Each Section Each Section

Purpose: 1-2 paragraphsPurpose: 1-2 paragraphs Methods: 1 pageMethods: 1 page Results: 1 page + figures and tablesResults: 1 page + figures and tables Discussion 1-2 pagesDiscussion 1-2 pages TOTAL LENGTH: 3-5 pages of TOTAL LENGTH: 3-5 pages of writtenwritten

materialmaterial Figures and tables should be included Figures and tables should be included

on additional pages. on additional pages.