Competency 5

CloningDNA Fingerprinting

KaryotypesGenetics

PedigreesMutations

What was Dolly?• Dolly the sheep was successfully cloned in

Britain in 1996 by the scientist “Ian Wilmut” and was put down in February 2003 after developing a lung infection and arthritis.

• Dolly the sheep became the first vertebrate cloned from the cell

of an adult animal.

Was the suspect at the crime scene?

Suspects Profile

Blood sample from crime scene

Victims profile

Stages of DNA Profiling

DNA is negatively charged so it is attracted to the positive end of the gel.

The shorter DNA fragments move faster than the longer fragments.

DNA is separated by size.

Karyotypes

• A pictorial display of metaphase chromosomes from a mitotic cell

• Homologous chromosomes- pairs • Chromosomes pairs 1-22 are called

autosomes• Chromosome pair 23 are called the sex

chromosomes

Trisomy 21 - Down Syndrome

Down Syndrome

• Cause:

Nondisjunction of

chromosome 21

• Three copies of chromosome 21 =

“TRISOMY 21”

Nondisjunction

• Every cell in that baby’s body will have 3 copies of this chromosome instead of 2.

• This condition is called TRISOMY• Trisomy 21 = Individual has 3 copies of

chromosome # 21.

Nondisjunction

• Chromosomes FAIL TO SEPARATE during meiosis

• Meiosis I Nondisjunction• Meiosis II Nondisjunction

Chromosomal Translocation

Material is swapped with another chromosome

Causes: Burkitt’s Lymphoma

(cancer of the lymph nodes, in children)

Chromosomal Inversion

a segment of genes flip end-to-end on the chromosome

Causes: Four-Ring Syndrome

(cleft pallate, club feet, testes don’t descend)

Chromosomal Duplication

A segment of genes is copied twice and added to the chromosome

Causes: Charcot–Marie–Tooth disease

(high arched foot, claw feet, confined to a wheelchair)

Chromosomal Deletion

One or more genes are removed

Causes: Wolf-Hirschhorn syndrome (severe mental retardation)

cri du chat syndrome (mewing sounds, mental retardation)

Gene Mutations: 2 Types

Point Mutation Frameshift Mutation

• Monosomy: The condition in which there is a missing chromosome.

• Trisomy: The condition in which there are 3 of a specific chromosome.

Karyotypes

Disorder: Trisomy:Definition: Cystic Fibrosis #7Mucus accumulate in

the lungsEdward’s Syndrome #18

Down’s Syndrome #21

Patau’s Syndrome #13

Genetic Disorders• PKU: Inability to code for an enzyme needed for

changing the amino acid phenylaline to tyrosine.• Turner’s Syndrome: Sex chromosome make up is

XO. (She/He)• Klinefelter’s Syndrome: Sex chromosome makeup

is XXY (He/She)• Tay-Sachs Disease: Inability to synthesize an

enzyme that prevents lipid buildup in the brain• Sickle Cell Anemia: Blood cells are sickled shaped

Crosses:

1.Monohybrids2.Dihybrids3.Incomplete Dominance4.Co-Dominance5.Multiple Alleles6.Sex linked Traits

What is a pedigree chart?How is it used?

• One important tool a geneticist uses to trace the inheritance of traits is a pedigree chart.

• A pedigree chart is one that geneticists use to track an inherited trait through several generations of a family to try to understand how it is inherited.

How do you read a pedigree chart?

• A CIRCLE represents a FEMALE.

• A SQUARE represents a MALE.

• A horizontal line represents marriage.

• A vertical line and brackets connects

parents to children.

How do you read a pedigree chart?

• A shape that is not shaded indicates that the person does NOT have the trait.

• A shape that is half-shaded indicates that the person is a “carrier” (has 1 allele).

• A shape that is completely-shaded indicates that the person has the trait (homozygous – both alleles for the trait).