Human Heredity

Parents give genes•_______

reproductive cells

-sperm & egg

23 chromosomes

•Zygote-–Fertilized eggs

•46 Chromosomes–23 pairs of chromosomes

•Male __•Female XX

•Environmental effects ________ gene expression but are not inherited.

________ Twins

Human Traits

Human Blood Groups•______ alleles

–Gene with 3 or more alleles

Ex. ABO blood

Blood Typing• Karl __________• Types

–A, B, AB, O•Difference is the _______

•A accepts A and O blood•B accepts B and O

blood•__ accepts A,B&O blood•O accepts O blood only

–O is Universal donor

3 alleles code for blood typesIA, IB, i

• O ii• A IA IA, IAi• B IB IB, IBi• AB IA IB

Rh Blood Groups•__ antigen- Named after Rhesus monkey

•_ & - Blood types•+ has it, - doesn’t

________ Disease• _______ Gene that causes

muscle loss and nervous cell ________

• Gene is expressed only in 30’s and 40’s

• A few are caused by dominant alleles–Examples: __________,

Huntington’s disease

Polygenic Traits•Traits controlled by a number of genes–Height–Skin Color

Sickle Cell Anemia

Is it Good or Bad?

Some Cells are _____ shaped not round

_______ Genes Cause Sickle Cell

•HA HA -normal cell•HS HS - sickle cell•HA HS- half/half

HA HA

Person Lives out normal life

HS HS

•Sickle cells get stuck in capillaries

•Body parts die from lack of _____

HA HS

• Survive with _______ problems• Have some _______ to Malaria

-equatorial regions

-Survive better

Sickle Cell Anemia

Is it Good or Bad?

Sex-Linked Inheritance

Non-disjunction Disorders

•Turner syndrome•_________ syndrome•Down syndrome

Turner syndrome•Female ________•Sex organs never develop (Sterile)

•Abbrev. ___ or 45XO

Klinefelter syndrome•______ in appearance•Sterile•Abbr. _____

Down Syndrome•Mentally disabled•______ 21

–Extra 21st Chromosome–Stocky, smaller organs

Die early

Down Syndrome

No baby has been born without at least one _ chromosome

No baby has been born without at least one _ chromosome

If there is a Y chromosome present the appearance of the

child is MaleEx. 48XXXY

__________

Sex-Linked Disorders

Genes carried on X or Y chromosome

•Color Blindness•___________•Muscular Dystrophy

Color Blindness

8% of males, 1% of females

Allele is carried on X

Hemophilia•Males-1 in 10,000•Females-_____________•Blood doesn’t clot

• A high incidence of hemophilia has plagued the ____ families of Europe

QueenVictoria

Albert

Alice Louis

Alexandra CzarNicholas IIof Russia

Alexis

Muscular ________• Skeletal muscle wastes away.• Dystrophin protein is

defective• Usually die by adulthood

Sex-______ Traits•Baldness

–Normal hair B–Bald b–Females only get thin hair

Diagnosis of Genetic Disorders

Before Birth

•Microscope matchup•___________

–Uses fluid from around baby

•Chorionic villus biopsy

Before Birth

•Amniocentesis–Uses _____ from around baby

•Chorionic villus biopsy–Uses cells from the ______ around the baby

• Karyotyping and biochemical tests of fetal cells and molecules can help people make reproductive decisions– Fetal cells can be obtained through amniocentesis

Connection: Fetal testing can spot many inherited disorders early in pregnancy

Amnioticfluid

Fetus(14-20weeks)

Placenta

Amnioticfluidwithdrawn

Centrifugation

Fetalcells

Fluid

Uterus Cervix Cell culture

Severalweeks later Karyotyping

Biochemicaltests

• Chorionic villus sampling is another procedure that obtains fetal cells for karyotyping

Fetus(10-12weeks)

Placenta

Chorionic villi

Suction

Several hourslater

Fetal cells(from chorionic villi)

Karyotyping

Some biochemical

tests

Ethical Issues

Should genetic counseling be a cause for abortion?

• Family pedigrees are used to determine patterns of inheritance and individual genotypes

DdJoshuaLambert

DdAbigailLinnell

D_Abigail

Lambert

Female

DdElizabeth

Eddy

D_JohnEddy

? D_HepzibahDaggett

?

?

ddDdDdDdddDdDd

MaleDeaf

Hearing

ddJonathanLambert