Making a Pedigree Making a Pedigree ChartChart

Making a Pedigree Making a Pedigree ChartChart

A family history of a genetic condition

Quick Review• Genotype = what genes someone has • Genes are usually represented by a letter, a

capital letter for the dominant trait, a small case for the recessive.

• Example: Tongue Rolling is dominant, so we use R to represent the tongue rolling

• Inablility to roll your tongue is recessive so we use r to represent the non-rolling gene

• For every trait, you get a gene from each parent

Genotypes and Phenotypes

• Mom and Dad are Rr-that is their genotype, they can also be described as heterozygous-they have 1 of each gene

• What is their PHENOTYPE?

• The youngest son has a genotype of rr-he is Homozygous recessive-2 copies of the recessive gene

• His phenotype?

I can’t Roll my Tongue!

Some common dominant and recessive traits

• Widow’s peak is dominant.

• You can be homozygous dominant (WW) or heterozygous (Ww) and you will have widow’s peak

• What is your genotype and phenotype if you’re homozygous recessive?

Making a Pedigree Chart

• Pedigree charts are made to chart family history and see how traits are passed

• A genetic counsellor will use pedigree charts to help determine the distribution of a disease in an affected family

Symbols

• Shade individuals that have the trait you’re studying

• Boys = squares (Lucy always calls Charlie Brown a ‘block head’)

• Girls = circles

• Married-connected at side

• Siblings-connected at TOP not at the side (hopefully not siblings AND married)

• Oldest child-to the left

• Question-if shaded individuals in this pedigree have blue eyes, what is the GENOTYPE of the parents?

Other• Divorced,

separated• Deceased• Identical twins• Fraternal twins

Generations are identified by Roman numerals

Organizing the pedigree chart

I

II

III

IV

Organizing the pedigree chart

• Individuals in each generation are identified by Arabic numerals numbered from the left

• Therefore the affected individuals are II3, IV2 and IV3

I

II

III

IV

1 2 3 4 5 6 7

What’s going on?Shaded = blue eyes

• 1 and 2 split after having 4, 2 then had kids with 3 and split with her too after 5-9 were born

• Genotypes of 1, 4,7?

• Genotypes of 2 & 3?• Genotypes of 5,6, 8,

9, 10, 11, 12?

Time to practice…

1. Complete the practice worksheet on pedigrees in class (we will review)

2. Pedigree swap activity3. Homework assignment – YOUR

CHOICE!

Make your own pedigree

• Using your own family, make your own pedigree chart

• Must at LEAST include grandparents, parents, & your generation

• Pick one easy dominant or recessive trait and shade individuals that have it. You can guess who has it if you don’t know for sure. (Don’t pick a trait that EVERYONE in your family has)

• Label yourself, grandparents, cousins, etc

• Put a key on the pedigree so I know what shaded means. Ex.- shaded people have widow’s peak

OR…you may create a pedigree chart for a fictional family of your choice. For example, a family in a book you read or a movie you have seen (ex: Twilight series, Harry Potter, etc)

Which technology Which technology was important to the was important to the development of the development of the

cell theory?cell theory?

Which technology Which technology was important to the was important to the development of the development of the

cell theory?cell theory?

MicroscopeMicroscope

The monk who The monk who worked with pea worked with pea

plants to discover the plants to discover the patterns of heredity patterns of heredity

waswas

The monk who The monk who worked with pea worked with pea

plants to discover the plants to discover the patterns of heredity patterns of heredity

waswas

Gregor MendelGregor Mendel

The person The person responsible for taking responsible for taking the x-rays which led the x-rays which led to the discovery of to the discovery of

the structure of DNA the structure of DNA waswas

The person The person responsible for taking responsible for taking the x-rays which led the x-rays which led to the discovery of to the discovery of

the structure of DNA the structure of DNA waswas

Francis CrickFrancis Crick

Chemical which Chemical which contains the contains the

information for an information for an organism’s growth organism’s growth and functions is theand functions is the

Chemical which Chemical which contains the contains the

information for an information for an organism’s growth organism’s growth and functions is theand functions is the

DNADNA

The unit of heredity The unit of heredity that determines a that determines a particular trait is particular trait is

known as aknown as a

  

The unit of heredity The unit of heredity that determines a that determines a particular trait is particular trait is

known as aknown as a

  

PhenotypePhenotype

The smallest unit that The smallest unit that can perform the basic can perform the basic activities of life is the activities of life is the

The smallest unit that The smallest unit that can perform the basic can perform the basic activities of life is the activities of life is the

CellCell

Four molecules that Four molecules that write the DNA code write the DNA code

areare

Four molecules that Four molecules that write the DNA code write the DNA code

areare

– Nucleotides

Different forms of the Different forms of the same gene are calledsame gene are calledDifferent forms of the Different forms of the same gene are calledsame gene are called

AllelesAlleles

Traits that are coded Traits that are coded for on DNA are for on DNA are

considered _________; considered _________; while those that are while those that are obtained by means obtained by means

other than genetically other than genetically are considered are considered

  

Traits that are coded Traits that are coded for on DNA are for on DNA are

considered _________; considered _________; while those that are while those that are obtained by means obtained by means

other than genetically other than genetically are considered are considered

  

Inherited; acquiredInherited; acquired

The step that follows The step that follows mitosis during which mitosis during which

the cytoplasm divides the cytoplasm divides is calledis called

The step that follows The step that follows mitosis during which mitosis during which

the cytoplasm divides the cytoplasm divides is calledis called

CytokinesisCytokinesis

What is the proper What is the proper order for the steps of order for the steps of

mitosis?mitosis?

What is the proper What is the proper order for the steps of order for the steps of

mitosis?mitosis?

DNA replicates duringDNA replicates duringWhich phase?Which phase?

DNA replicates duringDNA replicates duringWhich phase?Which phase?

An example of a An example of a codominant human codominant human

trait istrait is

An example of a An example of a codominant human codominant human

trait istrait is

a)Frecklesa)Frecklesb)Earlobesb)Earlobesc)Hair colorc)Hair colord)Blood typed)Blood type

An example of a An example of a recessive trait in recessive trait in

humans ishumans is

An example of a An example of a recessive trait in recessive trait in

humans ishumans is

a)Frecklesa)Frecklesb)Unattached earlobeb)Unattached earlobec)Straight hairc)Straight haird)Brown eyesd)Brown eyes

A human female A human female would have which set would have which set of sex chromosomes?of sex chromosomes?

A human female A human female would have which set would have which set of sex chromosomes?of sex chromosomes?

a)XXa)XXb)XYb)XYc)YYc)YY

d)XxYyd)XxYy

Cells that contain half Cells that contain half the usual number of the usual number of chromosomes arechromosomes are

Cells that contain half Cells that contain half the usual number of the usual number of chromosomes arechromosomes are

GametesGametes

Crossing organisms to Crossing organisms to produce offspring produce offspring

with desirable trait is with desirable trait is calledcalled

Crossing organisms to Crossing organisms to produce offspring produce offspring

with desirable trait is with desirable trait is calledcalled

Selective breedingSelective breeding

Any change in DNA is Any change in DNA is calledcalled

Any change in DNA is Any change in DNA is calledcalled

MutationMutation

Radiation treatments Radiation treatments can be dangerous can be dangerous because they canbecause they can

  

Radiation treatments Radiation treatments can be dangerous can be dangerous because they canbecause they can

  

Kill healthy cellsKill healthy cells

Table which Table which represents the represents the

possible combination possible combination of parental allelesof parental alleles

Table which Table which represents the represents the

possible combination possible combination of parental allelesof parental alleles

Punnett squarePunnett square