Chromosomes and Human Genetics

Chapter 11

KaryotypingSeparating

chromosomes for an individual

The human chromosomes have been karyotyped to see what normal should look like.

Pedigree

A chart showing genetic conditions among individuals

Genetic EngineeringProcess and study of reconfiguring an

organisms genes in order to add or remove a gene.

AneuploidyIndividual has one less or extra

chromosomeMost miscarriages are caused by this

Down’s SyndromeAn extra

chromosome appears at location 21. Also called Trisomy 21.

Causes mental retardation and heart defects

PolyploidyHaving three or

more of each type of chromosome

NondisjunctionOne or more pairs

of chromosomes fail to separate during mitosis or meiosis

Autosomal InheritanceRecessive - Traits are carried on an

autosomal chromosome through a recessive allele

Dominant – traits are carried on an autosomal chromosome through a dominant allele.

AlbinismAbsence of

pigmentation.Caused by

autosomal recessive inheritance.

X-Linked Recessive InheritanceThe trait is carried on the X

chromosome through a recessive allele. These disorders tend to be seen most frequently in males because males only have one X chromosome, and if they receive it, the allele will not be hidden.

Hemophilia, colorblindness

Color BlindnessInability to

distinguish between some or all colors.

X-Linked recessive inheritance

HemophiliaBleeding disease.Impaired clotting

ability.Caused by X-

Linked recessive inheritance.

Genetic MutationsDuplication – gene sequences that are

repeated several to many hundreds of times.

Inversion – DNA sequence reverses.Deletion – loss of a segment of DNA.

Can be caused by viruses or environmental factors.

Translocation – a broken part of a chromosome becomes attached to a nonhomologous chromosome. Most of these are reciprocal (chromosomes exchange sequences).

Leukemia can be caused this way.

Works Cited http://homepages.uel.ac.uk/V.K.Sieber/solidktp.jpg http://www.ucl.ac.uk/~ucbhjow/medicine/RGD/images/ped_sym

b.gif http://www.asklenore.info/miscarriage/print/images/fig3.jpg http://www.biology.iupui.edu/biocourses/n100/images/

11nondisjunction.gif http://www.ucl.ac.uk/~ucbhjow/bmsi/lec7_images/47_xx_21.gif http://www.foxnews.com/images/

297291/0_61_062507_albino_goat.jpg http://www.humanillnesses.com/original/images/

hdc_0001_0003_0_img0234.jpg ricksaphire.com/colorblind/ http://healthresources.caremark.com/Imagebank/

Articles_images/Hemophilia.gif