Transcript Cell Reproduction

Cell Reproduction
Chromosomes
Mitosis
Meiosis
Two Types of Cells
Prokaryotes
• No nucleus
• No Organelles
• Unicellular but can form
filaments and colonies
• Smaller—1-5 μm across
• Example: bacteria
• Binary fission is the
process prokaryotes
use to divide
Eukaryotes
• Has nucleus
• Has organelles
• Can be either
unicellular or
multicellular
• Larger—10-100 μm
across
• Examples: animals,
plants, fungi, yeast
• Mitosis ONLY occurs
in EUKARYOTES
Why do cells
need to divide
and reproduce in
eukaryotes?
1. Repair of tissue
(like a broken bone)
Why do cells
need to divide
and reproduce in
eukaryotes?
2. So the organism can grow
Like a baby….their body is
growing very, very fast
Tree Growth
CANCER
So….cells divide
and make new
cells
It’s called MITOSIS
Everybody say it….
MITOSIS
Cell Division
• Cell Division is the process by which
cells reproduce.
• information in the cell is contained in
genes → genes code for proteins →
proteins carry out cellular functions
• Each body cell that results from cell
division must have an exact copy of
the DNA in the original cell.
Chromosomes
Chromosome Structure
Chromosome
Structure
Chromosome Structure
Chromosome
Structure
Chromosome Number
Mitosis
• Mitosis: the division of the cell
nucleus in which the chromosomes
in the parent cell divide into two
identical sets
• In somatic cells (body cells), the
number of cells is increased
without changing the information
contained in the DNA or the
amount of DNA in those cells.
Cell Cycle
Overview
Important Structures
Equator
Polar
Fibers
Asters
Kinetechore
Centrioles
Kinetechore
Fibers
Mitosis in Plants
Cleavage Furrow & Cell Plate
Meiosis
Overview
Meiosis
Genetic Recombination
• Genetic Recombination: the process
that results in chromosomes being
arranged in many different ways
• crossing-over between homologues or
chromatids
• homologous pairs separate
independently in meiosis I
• sister chromatids separate
independently in meiosis II
CROSSING
V
E
R
CROSSING
V
E
R
Independent
Assortment
Karyotype
Diploid vs. Haploid
• Diploid (2n): a cell that
contains both chromosomes
of a homologous pair
• Humans = 46 (somatic cells:
body cells)
• Haploid (n): a cell that has
only one chromosome of
each homologous pair
• Humans = 23 (gametes:
egg and sperm)
Mitosis