1. Heredity Notes

2. DNA  DNA- (Deoxyribonucleic acid)- genetic material that carries the information about an organism and is passed from parent to offspring.  Humans contain 23 pairs of chromosomes- a total of 46 chromosomes (23 from mom and 23 from dad).

3. Heredity  Heredity-the passing of traits from parents to offspring.

4. Back to Nucleus  DNA is loose strands in the nucleus (chromatin), but once a cell gets ready to divide, it produces condensed strands (Chromosomes).  Chromosomes must replicate before they can divide. Why? You don’t want to lose half of yourself do you?

5.  DNA are made up four different nitrogen bases pairs. Adenine (A), Thymine (T), Guanine (G), Cytosine (C) are the nitrogen bases.  Adenine always pairs with Thymine and Guanine always pairs with Cytosine.  With these four base pairs, there are 8,000,000 possible outcomes between two parents and the arrangement of chromosomes.

6. Heredity Vocabulary  Gene- a set of information that controls a trait; a segment of DNA on a chromosome that codes for a specific trait (hair color, eye color, ear lobes).  Traits- characteristics that an organism can be pass on to its offspring through its genes.

7. Heredity Vocab Continued  Alleles- the different forms of a gene.  Homozygous trait- having two identical alleles for a trait.  Heterozygous trait- having different alleles for a trait.  Genotype- genetic make up.  Phenotype- physical appearance or visible trait.