Chromosome and DNA Replication

							Chromosome and DNA
     Replication
        Prokaryotes
Genetic material is a single
loop of DNA
Located in the cytoplasm
        Eukaryotes
Genetic material in the form
of a chromosome
Located in the nucleus
Eukaryotes
       Chromosomes
The number of
chromosomes vary among
species
Humans have 46
chromosomes (23 prs)
Chromosomes
       Human
       Karyotype
  Chromosome Structure
Chromatin – DNA tightly
wrapped around proteins
(histones)
Chromatin supercoils to form
chromosome
Chromosome visible during
mitosis
Chromosome Structure
       DNA Replication
The  copying of DNA prior to
the cell undergoing division
It occurs at multiple sites
along the DNA strand
simultaneously
     DNA Replication (steps)
1.   Chromosome uncoils (gyrase)
2.   DNA helix unzips into 2
     strands (helicase)
3.   Two new complimentary
     strands are constructed
     following base pairing rules
     (DNA Polymerase)
DNA Replication (steps)
        DNA Replication
A   Semi-Conservative Process
 The   original strand serves as a
 template for the new strand
 The resulting DNA molecules
 are made up of one parent
 (original) strand and one
 daughter (new) strand
DNA Replication
DNA Replication