4 Terms to Know Autosomes – chromosomes 1-22 Sex chromosome – chromosome 23Monosomy - missing a chromosome (2n-1)Trisomy - one extra chromosome (2n+1)Nondisjunction - when chromosomesfail to separate properlyAnswer questions on right hand side.
5 Let’s Review…. How many chromosomes come from your Father? 23 How many chromosomes come from your Mother?What are chromosome pairs 1-22 called?What is chromosome pair 23 called?2323AutosomesSex chromosome
6 Turner’s syndrome Missing a X chromosome on 23rd chromosome Causes underdeveloped ovaries, short stature, webbed, and only found in women.Bull neck and broad chest. Individuals are sterile and lack expected secondary sexual characteristics.Mentally handicapped typically not evident.
7 Kleinfelter’s syndrome (or Klinefleter’s) Caused by nondisjunction of the X chromosome on 23rd chromosome (XXY, XXYY)Males with some development of breast tissueIndividuals have little body hair, typically tall, and have small testes.Infertility results fromabsent sperm.Mentally handicapped mayor may not be present.
8 Down’s Syndrome Caused by non-disjunction of the 21st chromosome. The individual has a trisomy 21.
9 The very tragic disease… hairy ears Y-linked trait, which is extremely rare.Symptoms… hairy earsOnly 1 cure known….
10 Flip Paper Over Karyotype Practice: circle any abnormalities Trisomy 21 = Down’s Syndrome#2#1XO = Turner’s Syndrome
11 Flip Paper Over Karyotype Practice: circle any abnormalities Trisomy 18 = Edward’s Syndrome#4#3XXY = Kleinfelter’s Syndrome
12 Flip Paper Over Karyotype Practice: circle any abnormalities Trisomy 13 = Patau Syndrome#5
14 PedigreeDiagram that shows how a trait is passed from generation to generationKey: Female (normal) Female (has the trait)Male (normal) Male (has the trait)Married MarriedSiblings Carrier(husband and wife)(brothers and sister)
15 How to read pedigrees? How many generations are shown? How many affected people are there?How many affected people are female?How many affected people are male?3743
16 Sex-linked recessive pedigree All carriers are female. Most affected are male.Answer last question on right hand side.