Human Heredity

Parents give genes _______ reproductive cells -sperm & egg 23 chromosomes

Zygote- –Fertilized eggs 46 Chromosomes –23 pairs of chromosomes Male __ FemaleXX

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

A, B, i 3 alleles code for blood types I A, I B, i O  ii  AA, A iA  I A I A, I A i B  BB, B iB  I B I B, I B i AB  ABAB  I A I B

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 H A H A -normal cell H S H S - sickle cell H A H S - half/half

H A Person Lives out normal life

H S Sickle cells get stuck in capillaries Body parts die from lack of _____

H A H S 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 21 st Chromosome –Stocky, smaller organs Die early

Down Syndrome

No baby has been born without at least one _ chromosome

If there is a Y chromosome present the appearance of the child is Male Ex. 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 Queen Victoria Albert AliceLouis AlexandraCzar Nicholas II of Russia Alexis

Muscular ________ Skeletal muscle wastes away. Dystrophin protein is defective Usually die by adulthood

Sex-______ Traits Baldness –Normal hair B –Baldb –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 Amniotic fluid Fetus (14-20 weeks) Placenta Amniotic fluid withdrawn Centrifugation Fetal cells Fluid UterusCervix Cell culture Several weeks later Karyotyping Biochemical tests

Chorionic villus sampling is another procedure that obtains fetal cells for karyotyping Fetus (10-12 weeks) Placenta Chorionic villi Suction Several hours later 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 Dd Joshua Lambert Dd Abigail Linnell D_ Abigail Lambert Female Dd Elizabeth Eddy D_ John Eddy ?D_ Hepzibah Daggett ? ? ddDd ddDd Male Deaf Hearing dd Jonathan Lambert