7.4 human genetics and pedigrees set up cornell notes on pg. 87 topic: 7.4 human genetics and...

7.4 Human Genetics and PedigreesSet up Cornell Notes on pg. 87•Topic: 7.4 Human Genetics and Pedigrees

•Essential Questions:

1. NO EQ

2.1 Atoms, Ions, and Molecules

7.4 Human Genetics and Pedigrees

KEY CONCEPT A combination of methods is used to study human genetics.


86Autosomal Dominant Pedigree

Autosomal Recessive Pedigree

Autosomal Recessive Pedigree #2


KEY CONCEPT A combination of methods is used to study human genetics.


• The basic principles of genetics are the same in all sexually reproducing organisms.

– Inheritance of many humantraits is complex

– Single-gene traits areimportant in understandinghuman genetics.

Ex: widow’s peak

Widow’s peak


Boxes = malesCircles = females Shaded = they show the traitWhite = does not show traitHalf shaded = carrier (Carrier= Only for recessive disorders)Offspring is dead=

A pedigree is a chart for tracing genes in a family.

Pedigree Key:

• Phenotypes are used to infer genotypes

Please copy on Pg. 87


1. How many females are in this family?2. How many carriers?3. How many children were in generation two?4. How many offspring in generation three are affected by the trait?

Generation 1

Generation 2

Generation 3

Generation 4

Pg. 86 top margin


1. How many females are in this family? 112. How many carriers? 73. How many children were in generation two? 54. How many offspring in generation three are affected by the trait? 2

Generation 1

Generation 2

Generation 3

Generation 4


Widow’s peak

No Widow’s peak

In pedigrees that show Autosomal Dominant Traits/Disorders- Many family members will be shaded


Jamie and Joe married in 1912. Joe was homozygous dominant for a Widow’s Peak, while Jamie did not have a Widow’s Peak. They had two children: A son named Kyle and a daughter named Marie.

Kyle married a woman who had no Widow’s Peak.Marie never married. Kyle and his wife had three children: Two boys and a girl.

•Do Kyle and Marie have Widow’s Peaks?•What percent of Kyle’s children can we expect to have Widow’s Peaks? •What percent of Kyle’s children can we expect to have NO Widow’s Peaks?

On the top of pg. 86, please create this pedigree and answer the following questions. Always include GENOTYPE when possible:


Joe Jamie

Kyle Marie

WW ww


Joe Jamie

Kyle Marie

WW wwWW x ww•100% Ww

WwWw

1. Yes, Kyle and Marie have Widow’s Peaks


Joe Jamie

Kyle Marie

WW wwWW x ww•100% Ww

WwWw

Ww x ww•50% Ww and 50% ww? ? ?

1. Yes, Kyle and Marie have Widow’s Peaks2. 50% should have Widow’s Peaks3. 50% should have NO Widow’s Peaks

ww


In pedigrees that show Autosomal Recessive Traits/Disorders only a few organisms, will be shaded in. •Only will show up if heterozygotes mate, may skip a few generations before reappearing.• REMEMBER: if it is an autosomal recessive disorders CARRIERS will be present and must be half shaded in.


aa

On the middle of pg. 86, Fill in the genotypes of this incomplete pedigree. Shade if necessary.

Albinism is an autosomal RECESSIVE disorder


aa

aa

aaaa

Aa or AA?

You need to complete two Punnet sqs. to find out the answer


aa

aa

aaaa

Aa or AA?AA x aa•100% Aa?Aa x aa•50% Aa--50% aa


aa

aa

aaaa

Aa

Aa Aa Aa


aa

aa

aaaa

Aa

Aa Aa Aa

Aa or AA?

Can use previous Punnett Sq to answer this


aa

aa

aaaa

Aa

Aa Aa Aa Aa

Aa


aa

aa

aaaa

Aa

Aa Aa Aa Aa

Aa

Aa or AA?

AA x aa•100% Aa?Aa x aa•50% Aa--50% aa

Anyway to know for sure?


aa

aa

aaaa

Aa

Aa Aa Aa Aa

Aa

Aa or AA

?

? ?


aa

aa

aaaa

Aa

Aa Aa Aa Aa

Aa

Aa or AA

?

? ?

Aa or AA

SHADE AS NECESSARY


Mary and Joe were married in 1950.

Both Mary and Joe were carriers for a fatal recessive disorder called Cystic Fibrosis.

They had three children: A son named Pete who was a carrier, a son named Charles who was not a carrier and did not have the disease, and a girl named Isabel who died from Cystic Fibrosis.

Pete married a woman who was homozygous dominant. Pete and his wife are worried about having a child with Cystic Fibrosis.

Should they worry? What are the chances of any of their children having Cystic Fibrosis? Carriers?

Bottom of Pg. 86


Joe Mary

PeteIsabel

Ff Ff

Ff ffFF

Charles

FF?


Joe Mary

PeteIsabel

Ff Ff

Ff ffFF

Charles

FF

FF x Ff•O%- No chance of any of their children having the disorder•50% will be carriers

They DO NOT need to be worried about having a child with CF

7.4 Human Genetics and PedigreesSet up Cornell Notes on pg. 89•Topic: 7.4 Human Genetics and Pedigrees

•Essential Questions:

1. NO EQ

2.1 Atoms, Ions, and Molecules

7.4 Human Genetics and Pedigrees: Sex-linked traits


Females can carry sex-linked genetic disorders.

• Males (XY) express all of their sex linked genes.• Expression of the disorder depends on which parent carries

the allele and the sex of the child.

XY


• In pedigrees showing Sex-linked traits: More males will be shaded in because they do not have another X to mask the disorder Ex: Color blindness

males

females


X-linked Color Blindness- Recessive XMXM= NormalXMXm= carrierXmXm= CBXMY= NormalXmY= CBXmY

XmY

XmY XmY

XMY

XMXm

XMXm XMXm XMXm

XMXM or XMXm

?

On pg. 88, Fill in the genotypes of this incomplete pedigree. Shade if necessary.


• A karyotype is a picture of all chromosomes in a cell.

X Y


• Karyotypes can show changes in chromosomes.

– deletion of part of a chromosome or loss of a chromosome

– large changes in chromosomes– extra chromosomes or duplication of part of a

chromosome


• In down syndrome a person has an extra copy of chromosome 21.

• In Klinefelter’s syndrome a male has an extra X (XXY).


Pedigree Practice Worksheet


4 5

6 7 8 9

10 11 12 13 14 15 16

• How many males?• How many males have

hemophilia?

• How many females?• How many females have

hemophilia?


4 5

6 7 8 9

10 11 12 13 14 15 16

• How many males? 8• How many males have

hemophilia? 3

• How many females? 8• How many females have

hemophilia? 2


4 5

6 7 8 9

10 11 12 13 14 15 16

• How many marriages are there?


4 5

6 7 8 9

10 11 12 13 14 15 16

• How many marriages are there? 3


4 5

6 7 8 9

10 11 12 13 14 15 16

• How many children did the first couple have?

• How many children did the third couple have?

• How many generations are there?

• How many members in the 4th generation?


4 5

6 7 8 9

10 11 12 13 14 15 16

• How many children did the first couple have? 2

• How many children did the third couple have? 7

• How many generations are there? 4

• How many members in the 4th generation? 7


4 5

6 7 8 9

10 11 12 13 14 15 16

Now the harder part…Determine the GENOTYPES for as many of the family members as possible.

You can find all genotypes except for one.


4 5

6 7 8 9

10 11 12 13 14 15 16

Fill in the OBVIOUS genotypes first (the affected individuals)


4 5

6 7 8 9

10 11 12 13 14 15 16

XnXn

XnXn

XnY

XnYXnY

Fill in the OBVIOUS genotypes first •the affected individuals•The non-affected males


4 5

6 7 8 9

10 11 12 13 14 15 16

XnXn

XnXn

XnY

XnYXnY

XNY

XNY

XNY XNY

Then start at the top, and using Punnett Sqs. Determine the possible genotypes of the female offspring in each generation.

You may need to complete more than one!!!!!


4 5

6 7 8 9

10 11 12 13 14 15 16

XnXn

XnXn

XnY

XnYXnY

XNY

XNY

XNY

XNY XNY

XNXn XNXn

XNY XnXn/

• 100% XNXn


4 5

6 7 8 9

10 11 12 13 14 15 16

XnXn

XnXn

XnY

XnYXnY

XNY

XNY

XNY

XNY XNY

XNXn XNXn

XNY XNXn/

• 50%• 50%

XNXn

XNXN


4 5

6 7 8 9

10 11 12 13 14 15 16

XnXn

XnXn

XnY

XnYXnY

XNY

XNY

XNY

XNY XNY

XNXn XNXnXNXn or XNXN

?


4 5

6 7 8 9

10 11 12 13 14 15 16

XnXn

XnXn

XnY

XnYXnY

XNY

XNY

XNY

XNY XNY

XNXn XNXn

XNXn or XNXN

?

You need to complete 2 test crosses to figure out what mom is.


4 5

6 7 8 9

10 11 12 13 14 15 16

XnXn

XnXn

XnY

XnYXnY

XNY

XNY

XNY

XNY XNY

XNXn XNXn

XNXn or XNXN

?

XnY / XNXn

XnY / XNXN

and


4 5

6 7 8 9

10 11 12 13 14 15 16

XnXn

XnXn

XnY

XnYXnY

XNY

XNY

XNY

XNY XNY

XNXn XNXn

XNXn or XNXN

?

XnY / XNXn

XnY / XNXN

and

XNXn


4 5

6 7 8 9

10 11 12 13 14 15 16

XnXn

XnXn

XnY

XnYXnY

XNY

XNY

XNY

XNY XNY

XNXn XNXn

XNXn or XNXN

?XNXn

XNXn XNXn

SHADE THE CARRIERS IN AS NECESSARY


4 5

6 7 8 9

10 11 12 13 14 15 16

XnXn

XnXn

XnY

XnYXnY

XNY

XNY

XNY

XNY XNY

XNXn XNXn

XNXn

XNXnXNXn

?XNXn or XNXN

Now answer the rest of the questions.


Pedigree Worksheet

• Complete the back by yourself for homework

Part B• NOT SEX-LINKED (no XX or XY)• Determine if black fur or white fur is dominant or

recessive• Use pencil in case you make mistakes

Part C• Draw your own pedigree for the SEX-LINKED disorder• Outline each shape following the color-coding key


Who Gets the Money

Purpose: To solve a mystery involving genetics

Background: Mr. and Mrs. John Jones dies in a tragic farm accident when the tractor they were riding on rolled over in a ditch. Authorities found one million dollars hidden in a feed bin in the chicken coop. The couple is known to have a son, from whom they are estranged. This man is sole heir to the Jones fortune.

Procedure: Completes parts one, two, and three to find out who gets the money!


Who Gets the Money

• Part I: Dihybrid Cross• Part II: Punnett Squares• Part II: Sex-linked Traits

Blood type: Genotype possibilities

7.4 human genetics and pedigrees set up cornell notes on pg. 87 topic: 7.4 human genetics and...

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