Pedigree and Karyotype

Pedigree

Visual representation of a families history

What a pedigree shows

Shows relationships between family members and can show which individuals have traits or diseases.

Circle

Females

Square

Male

Filled in

Trait is expressed

Not filled in

Trait is not expressed

Half filled in

Carrier for the trait

Roman Numerals

Generation

Arabic Numerals

Individuals within the generation

Horizontal lines

Relationships

Vertical lines

Offspring

Carrier

Doesn’t physically express trait but still has it

Characteristics of dominant pedigree

• 1 parent must have the trait and will NOT skip generations

• Every affected individual has at least one affected parent

• Affected individuals who mate with unaffected individual have a 50% chance of transmitting trait to child

• 2 affected individuals may have unaffected children (may be heterozygous)

Recessive Pedegree

• neither parent is required to hv the trait since they can be heterozygous and will skip generations

• individual who is affected may have parents who are not affected

• All children of 2 affected individuals are affected

46

number of chromosomes a human has

23

How many pairs chromosomes are found in

Autosomes

Fist 22 pairs of chromosomes

Sex Chromosomes

23 rd pair of chromosomes are called

Males have ** chromosomes

XY

Females have ** chromosomes

XX

Dad

Parent that determines biological sex of offspring

Homologous pairs

These pairs are called ** pairs because One chromosome comes from mom and other from dad

Karyotype

Visual representation of an individual’s chromosomes

Nondisjunction

• Cause of chromosomal abnormalities

• When chromosomes fail to separate

Acrocentric

Submetacenyric

Metacentric

Aneuploidy

Organisms contain too many or too few chromosomes

Trisomy

These chromosomes are present in the chromosome pair

Monosomy

One chromosome is present in the chromosome pair.

3 steps in writing Karyotype Notation

• start with total # of chromosomes

• Add sex chromosomes

• Add any missing autosomal chromosomes