Chapter 8 section 1 Cell reproduction What is DNA? Contains information that determines

the Characteristics of an organism.

Chromosomes

Rod shaped structure made up of DNA and proteins.

Found in the nucleus of the cell. DNA Chromosomes Nucleus Cell

DNA wraps around proteins called histones.

Histones maintain the shape of the chromosomes and aid in the first packing of DNA.

Chromosomes consists of two identical halves.

Each half is called Chromatid.

Chromatids are attached at the Centromere.

Chromosomes

Each species has a characteristic number of chromosomes in the cell.

Human 46 FLY 8 Cat 32 Carrot 18 Dog 78

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.

Humans

44 chromosomes are called autosomes.

2 chromosomes are sex chromosomes.

The two copies of each autosomes are called homologous chromosomes.

Karyotype: photomicrograph of chromosomes.

Chapter 8 section 1 Cells What is DNA? Contains information that determines the

Characteristics of an organism.

Chromosomes

Rod shaped structure made up of DNA and proteins.

Found in the nucleus of the cell.

DNA --> Chromosomes -->Nucleus -->Cell

Human have 46 chromosomes

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

Humans

44 chromosomes are called autosomes.

2 chromosomes are sex chromosomes.

Karyotype: photomicrograph of chromosomes.