Module 6 Lesson 9 - 5 (Lab)
Completion requirements
Lesson 9 — Pedigree Analysis
Lab: Constructing a Real Pedigree
Choose from the two options below to complete a lab in constructing a pedigree.
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Constructing pedigrees is very helpful in determining inheritance patterns in families. Here is a chance for you to determine the inheritance pattern of a single trait in your own family or in a family willing to participate in your investigation. You
may work alone or with a partner for this exercise.
- Choose a single gene trait that can be found in your family or a family participating in your investigation.
- Interview the family members and determine which phenotype each individual exhibits.
- Using proper pedigree symbols, construct a pedigree for the trait.
- Your pedigree should show at least three generations to give a better look at the inheritance pattern.
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If you cannot find a family willing to participate in your investigation, complete the following activity, Building Pedigrees.
Building Pedigrees
Build the following pedigrees using the description provided and determine the genotypes of every individual.
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Tongue Rolling - The father cannot roll his tongue but the mother can. They have four children; one daughter cannot roll her tongue, and the remaining daughter and two sons can roll their tongues.
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Eye Colour - Both parents have brown eyes. They have four children: two sons have blue eyes and two daughters have brown eyes. One of their daughters married a brown-eyed man and they have a blue-eyed baby girl.
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Diabetes - Both parents do not have diabetes. They have three children (one daughter and two sons) and none of them has diabetes. The daughter married a man without diabetes, and they have one son who has diabetes.
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Hypertension - The father does not have hypertension, but he marries a woman with hypertension. None of their two children (boy and girl) has hypertension. The son marries a woman with hypertension, and they have a daughter who has hypertension.
Tongue Rolling Pedigree
Tongue rolling is autosomal dominant inheritance. Let T be the dominant tongue rolling allele, and let t be the recessive non-rolling allele.
Eye Colour Pedigree
Eye colour is autosomal recessive inheritance. Let B be the dominant brown eye colour allele, and let b be the recessive blue eye colour allele.
Diabetes Pedigree
Diabetes inheritance is autosomal recessive inheritance. Let D be the dominant normal allele, and let d be the recessive diabetes allele.
Hypertension Pedigree
Hypertension pedigree appears to be autosomal dominant inheritance. Let H be the dominant allele for hypertension, and let h be the recessive normal allele.
Tongue rolling is autosomal dominant inheritance. Let T be the dominant tongue rolling allele, and let t be the recessive non-rolling allele.
| I-1 |
tt
|
| I-2 | Tt |
| II-1 |
tt
|
| II-2 |
Tt
|
| II-3 | Tt |
| II-4 | Tt |
Eye Colour Pedigree
Eye colour is autosomal recessive inheritance. Let B be the dominant brown eye colour allele, and let b be the recessive blue eye colour allele.
| I-1 | Bb |
| I-2 | Bb |
| II-1 | bb |
| II-2 | bb |
| II-3 | B_ |
| II-4 | Bb |
| II-5 | Bb |
| III-1 | bb |
Diabetes Pedigree
Diabetes inheritance is autosomal recessive inheritance. Let D be the dominant normal allele, and let d be the recessive diabetes allele.
| I-1 |
D_ (I-1 and / or I-2 must be heterozygous.)
|
| I-2 | D_ (I-1 and / or I-2 must be heterozygous.) |
| II-1 |
D_
|
| II-2 |
D_
|
| II-3 | Dd |
| II-4 | Dd |
| III-1 | dd |
Hypertension Pedigree
Hypertension pedigree appears to be autosomal dominant inheritance. Let H be the dominant allele for hypertension, and let h be the recessive normal allele.
| I-1 | Hh |
| I-2 |
hh
|
| II-1 | Hh |
| II-2 |
hh
|
| II-3 |
hh
|
| III-1 |
Hh
|