1. Chapter 8 section 1 Cell reproduction  What is DNA?  Contains information that determines the Characteristics of an organism.

2. Chromosomes  Rod shaped structure made up of DNA and proteins.  Found in the nucleus of the cell.  DNA  Chromosomes  Nucleus  Cell

3.  DNA wraps around proteins called histones.  Histones maintain the shape of the chromosomes and aid in the first packing of DNA.

4.  Chromosomes consists of two identical halves.  Each half is called Chromatid.  Chromatids are attached at the Centromere.

5. Chromosomes  Each species has a characteristic number of chromosomes in the cell.  Human 46 FLY 8  Cat 32 Carrot 18  Dog 78

6. Sex chromosomes  Determine if the organism is a female or male.  Humans have X or Y chromosomes.  Female has two X chromosomes  Male have an X and a Y chromosomes.

7. Humans  44 chromosomes are called autosomes.  2 chromosomes are sex chromosomes.

8.  The two copies of each autosomes are called homologous chromosomes.

9.  Karyotype: photomicrograph of chromosomes.

10. Chapter 8 section 1 Cells  What is DNA?  Contains information that determines the Characteristics of an organism.

11. Chromosomes  Rod shaped structure made up of DNA and proteins.  Found in the nucleus of the cell.  DNA --> Chromosomes -->Nucleus -->Cell

12.  Human have 46 chromosomes

13.  Female has two X chromosomes XX  Male have an X and a Y chromosomes. XY

14. Humans  44 chromosomes are called autosomes.  2 chromosomes are sex chromosomes.

15.  Karyotype: photomicrograph of chromosomes.