Chromosomal Mutations & Karyotype Analysis

2. Chromosomal Mutations Change in # or structure of chromosome Happens as result of chromosomes breaking during meiosis Can occur in any organism, but normally in plants Five types

 Deletion Loss of part of chromosome

 Insertion/Duplication Part of a chromosome is repeated

 Inversion Part of a chromosome breaks out and reinserts backwards.

 Translocation Part of a chromosome breaks off & attaches to another chromosome

 Nondisjunction During Meiosis I, homologous chromosomes DO NOT separate correctly Result – too many or too few chromosomes in gamete

1. Look at the karyotype for the mutation

Down Syndrome – Trisomy 21 Intellectual and developmental disabilities specific physical features: flat face with upward slant of eyes, poor muscle tone, small hands & feet may have heart defects and respiratory problems National Down syndrome society http://www.ndss.org/

2. Look at the karyotype for the mutation

Trisomy 18 (Edwards syndrome) abnormal brain function that is very severe Heart, Kidney, intestinal problems Severe developmental delays usually die within 1-2 years old http://www.trisomy18.org/

3. Look at the karyotype for the mutation

Trisomy 13 (Patau syndrome) Extra fingers or toes Cleft lip or palate, Close set eyes, Scalp defects Problems with heart and brain structure die within 1-2 years old http://www.livingwithtrisomy13.org/

4. Look at the karyotype for the mutation

Trisomy on Sex Chromosomes XYY Syndrome – Extra Y normal appearance, may be taller than average, delayed development of speech and motor skills, not likely to be inherited http://ghr.nlm.nih.gov/condition/47xyy-syndrome XXX Syndrome – Triple X normal appearance, may be taller than average, delayed development of speech and motor skills, not likely to be inherited, sometimes sterile/infertile http://ghr.nlm.nih.gov/condition/triple-x-syndrome

5. Look at the karyotype for the mutation

Klinefelter’s Syndrome – XXY Sterile/infertile, normal appearance May be taller than average May have less body or facial hair delayed development of speech and motor skills NOT more inclined toward homosexuality or bisexuality http://www.genetics.com.au/pdf/factsheets/fs31.pdf

6. Look at the karyotype for the mutation

Monosomy Turner Syndrome – X Missing part or all of second X chromosome usually sterile/infertile Shorter than average height, heart and kidney problems, Normal intelligence 99% embryos miscarriage or stillborn http://www.nfxf.org/html/what.htm

Triploidy 69 chromosomes In plants, produced seedless watermelons

Practice # 2

Practice #3

Comparing mitosis & meiosis Function of process Number of parent cell(s) Number of daughter cells Number of Cell Divisions Produces body cells for growth or repair Produces sex cells for reproduction 1 1 2 4 1 2

Anywhere (muscles, skin, heart, etc) Mitosis Meiosis Anywhere (muscles, skin, heart, etc) Location in Body Amount of Chromosomes in parent cell Diploid Amount of Chromosomes in each daughter cell Type of Reproduction Sex cells diploid haploid Asexual Sexual