Patterns of InheritancePedigrees

PedigreesVisually displays inheritance patterns across

a family treeUseful for tracing the inheritance patterns of

disease and other genetic abnormalitiesAutosome: A non-sex chromosome, equal

number of copies of these chromosomes in males an females22 autosomal pairs in humans + 1 pair sex

chromosomes

Pedigree BasicsFemales represented by circles

Males represented by square

Unaffected or Carrier Affected

Unaffected or Carrier Affected

Pedigree BasicsHorizontal lines connect parents

Vertical lines denote descendants of parents

All offspring of the same parents are connected by horizontal lines

Parents

Offspring

Pedigree BasicsIndividuals are numbered left to right

starting from the first line and continue down the whole pedigree

1

3

2

54

1

76

Analyzing a PedigreeAutosomal Dominant Inheritance

Trait usually does not skip generationsAn affected person married to an unaffected

person should have approximately 50% of the offspring being affected. Affected individual is heterozygous for the trait Distribution of the trait should be close to equal

distribution among the sexes.

http://csm.colostate-pueblo.edu/biology/dcaprio/350/pedrules.html

Analyzing a PedigreeAutosomal Recessive Inheritance

Trait can skip generations. Distribution of the trait should be close to equal

distribution among the sexes. Traits are often found in pedigrees with consanguineous

marriages (Marriage among close relatives). If both of the parents are affected, all of the children

should be affected. Most affected individuals have "normal" parents who

were carriers. When an unaffected person is married to an affected

individual, all of the children are normal The normal parent is homozygous dominant

If a heterozygous carrier is married to an affected individual, then approximately half of the children should be affected. Showing that the "normal" parent is heterozygous

http://csm.colostate-pueblo.edu/biology/dcaprio/350/pedrules.html

CarriersCarriers of a trait will not express the trait

but their offspring may exhibit the trait

Blood TypesImportant to know blood type because giving

someone the wrong blood type leads to severe complications and death

Individuals carry antibodies to non-self blood types

Blood TypesBasic rules:

Type A : AA or AO Antibodies against type B

Type B: BB or BO Antibodies against type A

Type O: OO Universal donor, no antigens

Type AB: AB Universal acceptor, no antibodies

http://learn.genetics.utah.edu/content/begin/traits/blood/images/ABObloodsystem.gif

Lab ExamLab exam 2 Next Week

Know everything that is on the study guide

Exam 2 ReviewCell cycle lab

Know the phases of mitosis and be able to calculate time spent in each cell cycle (remember, 16 hours is not a constant!)

Punnet squaresKnow how to analyze genetic crossesKnow how to calculate genotypic and

phenotypic ratios, percentages, etc…Pedigrees

Be able to draw and analyze a pedigree

Exam 2 MaterialPCR

Understand what is happening in the reactionKnow what each reagent does and what role

each plays in the reactionKnow the rules of primer design, and be able

to make both forward and reverse primersKnow what is happening and the temperatures

during denaturation, annealing, and elongation.

TA Evaluations

Next LabExercise 6 on pedigrees dueLab quiz 2If you are taking BSC 196 DO NOT SELL

BACK YOUR TEXTBOOKS! You will use the same textbook that you used for this class.