1. DNA & Chromosomes Notes
DNA is tightly coiled up with proteins to make chromosomes
DNA is made of repeating monomers called nucleotides
4 DNA Nucleotide Bases: A, T, C, G
These nucleotide bases are what code for certain characteristics by creating for proteins
Chromosome structure breakdown:

2. Chromosomes 2 Types: Humans have 46 chromosomes
Sex Chromosomes – contain genes that determine the sex of individuals
Autosomes – contain all other genes for an individual
Humans have 46 chromosomes
2 Sex chromosomes (X & Y)
44 autosomes
Sex is determined by the sex-chromosome in the sperm
Egg always has X; sperm has 50% chance of X or Y
Some genes are “linked” to the sex chromosomes

3. Mutations
1. Chromosomal Mutations – involves changing of pieces of actual chromosomes
- Deletion Duplication
- portion of chromosome portion doubled totally removed and added
- Translocation Inversion
- Parts of chromosomes Piece is removed are switched and flipped backward
- Nondisjunction
- Chromosomes don’t separate during cell division

4. Mutations
2. Gene Mutations – affect genes at the nucleotide level (bases)
Substitution – 1 base swapped for another
Insertion - 1 base is added, causing a frame shift mutation
Deletion - 1 base is deleted, causing a frame shift mutation
Frame Shift – a change in the 3 DNA bases being read