Download Cell Division Mitosis and Meiosis

CELL DIVISION
MITOSIS AND
MEIOSIS
DNA
• deoxyribonucleic acid
• DNA contains the genetic instructions for our cells.
deoxyribonucleic acid
CHROMOSOMES
• Chromosomes are made of strands of DNA
• Most human cells have 46 chromosomes.
• A cell with all of the chromosomes present is called diploid
CHROMATIN
• Chromatin is chromosomes paired with proteins
CELL DIVISION IN PROKARYOTES
CELL DIVISION IN EUKARYOTES- THE
CELL CYCLE
G1 PHASE: CELL GROWTH
– This is when cells grow
– Increase in size
– Make new proteins and organelles
S-PHASE- DNA REPLICATION
– DNA is synthesized when chromosomes are copied
G2-PHASE: PREPARING FOR CELL
DIVISION
• Organelles are made
• Molecules are produced
M PHASE: CELL DIVISION
• Mitosis – this is when the cell actually divides!
• Steps in Mitosis:
• Prophase – Metaphase – Anaphase - Telophase
PROPHASE
• The chromosomes condense and
become visible
• The centrioles form and move toward
opposite ends of the cell ("the poles")
• The nuclear membrane dissolves
• The mitotic spindle forms
METAPHASE
• The Centrioles complete their
migration to the poles
• The chromosomes line up in
the middle of the cell ("the
equator")
ANAPHASE
• Mitotic spindles begin to shorten, pulling
chromatids apart
TELOPHASE
• The chromosomes decondense
• The nuclear envelope forms
CYTOKINESIS
• Cell membrane pinches in to form two cells
• These cells are now in interphase