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+Spark Starter

Spark Starter

1. A student crosses two fruit flies, one with long wings and the other with short wings. All of the offsprings come out having medium long wings. This is an example of which kind of inheritance?

2. When a breeder breeds two dogs one white and the other black he gets a puppy that is black with white dots. What can this breeder conclude about the mode of inheritance?

Identify the following as incomplete dominance, Codominance or complete dominance. Explain your answer in complete sentences + Pedigree.

+Family Tree

Why do we have family trees?

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+Pedigree = a Genetic Family Tree It tells helps us to keep track of traits as they are

passed down from generation to generation.

+How Do you Read a PedigreeGenerations are

HORIZONTAL All individuals sitting on

the same Horizontal plane are from one generation

1

233

generations!

+ Sex (Male or Female)

Squares =

Circles =

MALES

FEMALES

+Relationship (Married)

Circle all the married individuals

How many males are in this pedigree?

How many females are in this pedigree?

7

7

+Relationship (Siblings)

Draw a box around a set of siblings.

+How Do you Read a PedigreeShading of the Pedigree A Shaded individual

has the disorder Non-Shaded individual

DOESN’T have the disorder

Half-Shaded individual is a carrier of the disorder

+Pedigree for Widow’s peakWrite in the Genotype & Phenotype

Name Phenotype

Genotype

George

Arlene

Tom

Ann

Michael

Carla

Shaded individuals have a widow’s peak

+Pedigree for Widow’s peakWrite in the Genotype & Phenotype

Name Phenotype

Genotype

George No Widow’s Tt

Arlene Widow’s tt

Tom Widow’s tt

Ann No Widow’s Tt

Michael No Widow’s Tt

Carla Widow’s tt

Shaded individuals have a widow’s peak

+Autosomal Dominant

+AutosomalDominant Autosomal dominant

inheritance is characterized by several features.

Statistically, males and females are equally affected, and half of all children of an affected parent are affected and half of the children are unaffected.

In addition, affected individuals occur in every generation in the pedigree, and the trait is only passed through these affected individuals

+Autosomal Recessive

+AutosomalRecessiveThis unaffected person is the father of an affected son; both he and his wife are normal parents of an affected offspring, in concordance with the typical presentation of a recessive trait.

For this to happen, both parents must be carriers.

It is not surprising that his wife is a carrier, because she has affected siblings.

Her husband is probably a carrier, because this is the only likely way they produced a son who is affected.

Can skip generations

+Testing YOUR knowledge…

+Testing YOUR knowledge…

+Exit TicketIs it possible that the selected pedigree is for an AUTOSOMAL RECESSIVE TRAIT? Why?