Title yesterdays Notes Gene Mutations Get out spiral

Title yesterday’s Notes: Gene Mutations Get out spiral Grab Mutations Worksheet Turn to Page: 72 Title it: Chromosome Mutations Critical Question: What is the difference between gene mutations and chromosome mutations?

Chromosome vs. Gene • A Gene is section of DNA which can code for a single protein • A Chromosome is a entire strand of DNA coiled and condensed.

Humans usually have 23 pairs of chromosomes, 46 total. They are numbered 1 -22 with the 23 rd pair being the sex chromosome, XX in girls or XY in boys.

Karyotype

Scientists use Karyotypes to look for mutations. Karyotype A tool used to show the number and visual appearance of the chromosomes in an organism’s nucleus This is a norm huma n chro al karyoty p moso is a pi mes. e of cture A kary of chr up to oty o look a moso mes li pe t and ned comp are.

2 Main Types of Mutations 1. ) Chromosomal Mutations 2. ) Gene Mutations (What we did yesterday)

Chromosomal Mutations Chromosomes are your DNA!!! Any change involving long segments of DNA (thousands of nucleotides are changed)

How do these mutations occur? During Meiosis meiosis fertilization mitosis + development Sometimes mutations can occur here!! gametes Mom 46 meiosis Dad 46 23 egg 23 23 23 zygote fertilization sperm 46 46 46 mitosis & mitosis development

Types Chromosomal Mutations 1. 2. 3. 4. Duplication Inversion Translocation Non Disjunction

Chromosomal Duplication A segment of genes is copied twice and added to the chromosome (remember each letter is representing thousands of bases) Causes: Charcot–Marie–Tooth disease (high arched foot, claw feet, confined to a wheelchair)

Chromosomal Inversion a segment of genes flip end-to-end on the chromosome Causes: Four-Ring Syndrome (cleft pallate, club feet, testes don’t descend)

Chromosomal Translocation Material is swapped with another chromosome Causes: Promyelocytic Leukemia (translocation of chromosomes 15 and 17)

Nondisjunction the failure of one or more pairs of chromosomes to separate normally during cell division Produces gametes (sperm and egg) (and therefore a baby) with one missing chromosome or one extra chromosome

Down Syndrome Cause: Nondisjunction of chromosome 21 Three copies of chromosome 21 = “TRISOMY 21”

Chromosomal Mutations Most chromosomal mutations are lethal If the fetus survives: Tend to cause wide-spread abnormalities Example: Down Syndrome

Critical Question: What is the difference between gene mutations and chromosome mutations?

Using today and yesterday’s notes, complete the flow chart

Trisomy 21 - Down Syndrome

Mutation Practice Normal Chromosome ABCDEFGH A B C F E D G H Mutated Chromosome Inversion

Mutation Practice Normal Chromosome ABCDEFGH A B C C D D E F G H Mutated Chromosome Duplication

Mutation Practice Normal Chromosome ABCDEFGH JKLMNOPQ A B C D J K L M Mutated Chromosome NOPQEFG H Translocation