CELL CYCLE The cell cycle is the activities

CELL CYCLE The cell cycle is the activities that a cell goes throughout its life

INTERPHASE/MITOSIS/CYTOKINESIS 90% Of the cell’s life is in INTERPHASE; cell is growing & metabolizing 10% of the cell’s life is in MITOSIS/CYTOKINESIS; this is when the cell is dividing The cell must divide to make new cells and to stay small so that it will be efficient at getting needed nutrients

SEXUAL VS. ASEXUAL REPRODUCTION l l l SEXUAL REPRODUCTION Requires union of TWO cells EGG + SPERM Offspring are a combination of traits from each parent GENETIC VARIETY! l l l ASEXUAL REPRODUCTION One parent Offspring identical to parent Same exact genetic information Little variety

CHROMOSOMES The Chromosome Theory states that chromosomes are rod-shaped carriers of genetic information: DNA

What is a Chromosome? l l Chromosomes form when CHROMATIN (nuclear material containing DNA) condenses to form rodshaped structures Chromosomes are found in the nucleus but are only visible when the cell is dividing

What are the Parts of a Chromosome? l l Each replicated copy of DNA is called a CHROMATID The two chromatids that make up a chromosome are held together by a point called a CENTROMERE

THE CELL DURING INTERPHASE Cell membrane Nucleus Chromatin Nucleolus Small sphere inside Nucleus; where ribsomes are made Centriole

Relationship between Chromosomes, DNA, and Genes… l l l DNA is the genetic directions for the cell Chromosomes contain a portion of an organism’s DNA Each segment of that DNA that contains directions for a particular trait is a GENE

Chromosomes, DNA, Genes… DNA replicates (copies Itself) prior to cell Division…so every new Cell gets a complete Copy of DNA

A Human Karyotype l l l Human cells have 46 chromosomes Each chromosome has a matched chromosome called its HOMOLOGOUS chromosome. These matched pairs contain similar genetic information

A FEW MORE VOCAB TO KNOW: l l l INTERPHASE period b/w cell division; cell is growing/metabolizing SPINDLE formed during mitosis to pull chromosomes apart FURROW indention that forms as cell pinches in to divide

MITOSIS: Cell division; one cell divides into two cells producing 2 cells identical to the parent cell