DNA Replicati

onSection 12-2 in Textbook

ANIMAL CELL

Chromosomes- long thread like group of genes found in the nucleus.

Gene- sequence of nitrogen bases on a chromosome that code for one characteristic

DNA MODEL

THIS IS WRONG!!!!!!!

DNA Replication (Copying)

• Replication is necessary for MITOSIS. (Cell division)

• Occurs during INTERPHASE in NUCLEUS

Parent cell Daughter cells

Process of DNA Replication

• Enzyme “unzips” Original DNA Strand• Each side acts as a Template for the

NEW strand.• Enzymes lay down the complementarycomplementary

base pairs.– Thymine pairs with Adenine– Cytosine pairs with Guanine– In RNA Adenine pairs with Uracil

In DNA:

•Adenine bonds with Thymine

•Guanine bonds with Cytosine

In RNA:

•Adenine bonds with Uracil

•Guanine bonds with Cytosine

Original “Template”

Strand = RED

New Strand = BLUE

END RESULT…….. TWO EXACT COPIES OF DNA!!!

RNA vs DNA

Physical Differences:DNA: Double Helix RNA: Single Strand

Chemical Differences:

DNA: Deoxyribose sugar and Thymine RNA: Ribose sugar and Uracil

DNA Replication Animationhttp://www.ncc.gmu.edu/dna/repanim.htm