1. Heredity

2. In the past, traits were thought to be carried by the blood.
We now know what genes are responsible for certain traits and that the genes are in every cell.
We have used this information and completed the Human Genome project. The mapping out of the human DNA.

3. Pass it on
Every organism requires a set of instruction for specifying its traits.

4. The passing of traits from parent to offspring.
Heredity
The passing of traits from parent to offspring.

5. Heredity information is contained in genes, located in the chromosomes of each cell.
Each gene carries a single unit of information.

6. Chromosomes
They are composed of genes that provide the instruction for making all the proteins in an organism.

7. During cell division, the duplicated chromosomes separate so that one copy of each chromosomes is present in the two new cells.

8. This photomicrograph shows a specialized type of giant chromosomes called polytene chromosomes. Polytene chromosomes occur in many species of two-winged flies.

9. Homologous chromosomes
Chromosomes that have the same sequence of genes and have the same structure.

11. Down syndrome is often called Trisomy 21 because most people with this condition have three copies of the number 21 chromosome. Down syndrome almost always results in mental retardation, though the severity of the retardation varies.

12. Genes
Segments of DNA that carry hereditary instructions and are passed from one parent to offspring; located on the chromosome.

14. Different forms of a single gene.
Alleles
Different forms of a single gene.

16. An inherited trait of an individual can be determined by one or by many genes, and a singles gene can influence more than one trait. A human cell contains many thousands of different genes.

17. Traits
inherited characteristic: a quality or characteristic that is genetically determined.

18. Dominant Trait
The trait observed when at least one dominant allele for a characteristic is inherited.

19. Recessive Trait
A trait that is apparent only when two recessive alleles for the same characteristic are inherited.

20. Albinism, the lack of normal pigmentation, occurs in all races
Albinism, the lack of normal pigmentation, occurs in all races. A rare condition, albinism occurs when a person inherits a recessive allele, or group of genes, for pigmentation from each parent.

21. Human Genome Project
Completed in 2003, the Human Genome Project (HGP) was a 13-year project coordinated by the U.S. Department of Energy and the National Institutes of Health.

22. The end