1. DNA & Chromosomes
DNA is a type of organic macromolecule called Deoxyribonucleic Acid
DNA is made up of repeating monomers called Nucleotides
DNA has a distinct shape called a Double Helix
Segments of DNA that code for traits (eye color, etc) are Genes

2. DNA & Chromosomes Chromatin is DNA and histone loosely coiled together
DNA is wrapped up with proteins (histones) to form chromatin and chromosomes
Chromatin is DNA and histone loosely coiled together
Chromosomes are DNA and histone coiled very tightly together
Chromosomes appear as a “fat X” shape
Each side or half of a chromosome is called a chromatid
Both chromatids are held together by a centromere

3. Sexual Reproduction
Half of the chromosomes come from the mother; half from the father
Sex Chromosomes determine the sex of the organism (X & Y)
All other chromosomes are called Autosomes
Autosomes come in pairs (1 from mother; 1 from father)
The pairs that are the same size, shape, and types of genes are called Homologous Pairs (Homologues)
Ex: 1 chromosome has gene for hair color and 1 comes from EACH parent. They have same trait type, but not the same information (brown vs blonde)

4. DNA & Chromosomes
Sex chromosomes have different genes on them and have different sizes, so they can not be homologous
Cells having 2 sets of chromosomes are called Diploid (2n)
Humans (46); Fruit Fly (8); Plum (48); Adders Tongue Fern (1262)
Cells that come from sexually reproduced organisms that have only 1 set of chromosomes are called Haploid (1n)
These are the sex cells (egg and sperm)