Karyotypes& Chromosome Mutations

A karyotype is an organized profile of a person's chromosomes A normal human karyotype has 46 chromosomes (23 pairs): #1-22 are called autosomes #23 are called sex chromosomes

XX~ female XY~ male

Chromosomal Mutations Change in # of chromosomes OR structure of the chromosome Mutations can only be inherited if they occur in sex cells

Can YOU spot the chromosomal mutation??

1) Deletion Loss of all or part of a chromosome

2) Duplication Produce extra copies of parts of a chromosome.

3) Inversion Part of a chromosome breaks out and reinserts backwards.

4) Translocation Part of a chromosome breaks off & attaches to another chromosome

5) Nondisjunction Improper separation of homologous chromosomes during meiosis Results in extra or missing chromosomes in gametes

Remember—normally have 2 copies of each Types of Nondisjunction Trisomy~ 3 copies of a chromosome Monosomy~ 1 copy of a chromosome Remember—normally have 2 copies of each

Can you spot the mutation?

Down Syndrome – Trisomy 21 Intellectual and developmental disabilities may have heart defects and respiratory problems

Look at the karyotype for the mutation

Trisomy on Sex Chromosomes XYY Syndrome – Extra Y XXX Syndrome – Triple X

What is the mutation? Boy or Girl?

Trisomy 13 (Patau syndrome) Extra fingers or toes Cleft lip or palate (deformed lips) Heart and brain structure problems Die within 1-2 years of age

What is the mutation? Boy or Girl?

Turner’s Syndrome 45,X Webbed neck Infertile Swollen hands & feet at birth Heart defects