1. Chromosome Mutations and Chromosome Disorders

2. What is this diagram called?
A Karyotype

3. How many chromosomes are shown on a normal human karyotype?46

4. What are the pairs of each type of chromosome called?
Homologous chromosomes

5. Chromosomal mutations - involve many genes and are often fatal
Chromosomal mutations - involve many genes and are often fatal. If the zygote develops, the individual is often sterile.
Deletions-part of a chromosome is left out
Insertion/Duplication - occur when part of one chromatid breaks off and attaches to its sister chromatid.

6. Inversions-occur when part of a chromosome breaks out and is reinserted backwards
Translocations-occur when part of one chromosome breaks off and attaches to a different chromosome

7. Chromosomal Disorders
Nondisjunction-the failure of homologous chromosomes to separate properly during meiosis- both of the homologous chromosomes move to the same pole during meiosis.
can result in trisomy, monosomy, or triploidy
Homologous chromosomes fail to separate
Meiosis I:
Nondisjunction
Meiosis II

8. Trisomy - occurs when a gamete with an extra chromosome is fertilized by a normal gamete.
results in an individual with an extra copy of one of the chromsomes. In humans this individual would have 47 chromosomes.
Monosomy - occurs when a gamete missing a chromosome is fertilized by a normal gamete.
results in an individual with a single copy of one of the chromosomes. In humans this individual would have 45 chromosomes.

9. Triploidy - When a diploid gamete and a normal haploid gamete fuse, the zygote that results is triploid
there is no separation of homologous chromosomes causing diploid gametes to be produced.
it has three copies of the genetic information.
Rare and almost fatal in animals, but much more common in plants
often results in larger flowers or fruits of greater commercial value.