Presentation on theme: "A Chromosome Study Please pick up 1 set of chromosomes marked “normal” and 1 set of abnormal chromosomes labeled A B C or D, in addition to the lab handout."— Presentation transcript:
1 A Chromosome StudyPlease pick up 1 set of chromosomes marked “normal” and 1 set of abnormal chromosomes labeled A B C or D, in addition to the lab handoutIf you have scissors, begin cutting out the “normal” chromosomes. If not, begin reading the lab handout
2 Genetic ScreeningDeveloping fetuses can be tested for some severe genetic disorders by the process of karyotyping – which analyzes the chromosomes found in each cell.In this activity you will perform a karyotype on a “normal” set of chromosomes as well as an “abnormal” one.
3 Karotype: the most accurate test for Down’s Syndrome and other disorders. A karyotype is a picture of all of the chromosomes found in the cells of an organismChromosomes are stained, photographed, and then arranged from largest to smallest
4 Normal KaryotypeHumans almost always have 23 pairs of homologous chromosomes.Is this karyotype of a male or female?
5 Abnormal KaryotypeSome serious genetic disorders are caused by trisomy – a certain kind of mutation that gives an individual 3 copies of a chromosome.The karyotype below shows trisomy-21, better known as Down’s Syndrome.
6 Your Karyotypes You will be constructing 2 karyotypes. The first will be a normal male or female, (46 XY or 46 XX)The second will have a trisomy disorder.This is a lab activity!
11 What to do Cut out all of the chromosomes in the normal set. Pair up homologous chromosomes – they are identical in size and banding patternSeparate the sex chromosomes from the autosomes.Arrange the pairs of autosomes from largest to smallest.Label 1 side of the Human Karyotype Form as “normal.” Glue X chromosomes over the line marked X, Y chromosomes over the line marked Y.Glue the largest pair over the line numbered 1. Glue the next largest over the line numbered 2. Continue until the smallest pair is glued over number 22.Repeat the procedure for the abnormal set. There will be one extra chromosome in this set – but which number is it?