Reproduction
Asexual
Reproduction
Asexual Reproduction
 New
organisms develop from cells of
the parent – identical to parent
Asexual Reproduction
 All
cells arise from other cells by cell
division
Mitosis
 The
exact duplication of the complete
set of chromosomes
 Separation of these chromosomes into
two complete sets
 Chromosome – contains hereditary
information of an organism
Chromatids
Centromere
 Chromatid
– one strand
of a double-stranded
chromosome
 Centromere – structure
which joins the two
chromatids together
Mitosis
 Cytoplasmic
division results in formation
of two daughter cells
 Each daughter cell contains exact
number & type of chromosomes as
parent cell
Mitosis – The Process
1) INTERPHASE
 Replication of each single-stranded
chromosome during the non-dividing
period
 Results in a double-stranded
chromosome
Mitosis – The Process
2) PROPHASE
 Disintegration of the nuclear membrane
 Synthesis of a spindle apparatus to help
the division
Mitosis – The Process
3) METAPHASE
 Attachment of double-stranded
chromosomes to spindle apparatus at
centromere
Mitosis – The Process
4) ANAPHASE
 Replication of each centromere
 Results in formation of two singlestranded chromosomes
 Chromosomes move along spindle
apparatus to opposite ends of the cell
Mitosis – The Process
5) TELOPHASE
 Nuclear membrane forms around each
set of chromosomes
 Cell pinches in
Plant Mitosis vs Animal Mitosis
 Similar
process
 In animal cells:
– Centrioles form the spindle apparatus
– Cytoplasmic division is a “pinching in”
of cell membrane
 In plant cell, a cell plate is synthesized
Cancer
 Group
of diseases often characterized
by uncontrolled cell division of certain
abnormal cells
Asexual Reproduction
1) Binary fission
 Equal division of cell of an ameba,
paramecium, bacterium
 Result: Two equally sized organisms
Asexual Reproduction
2) Budding
 Unicellular organisms (yeast) – similar
to binary fission except cytoplasm
division is unequal
 New cells stay together (colony) or may
detach
Asexual Reproduction
 Multicellular organisms
(hydra) –
Production of multicellular outgrowth
from parent
 Detach or form colony
Obelia
colony
Asexual Reproduction
3) Sporulation
 Spores – single, specialized cells
 Survive very well – withstand tough
conditions
 Released from parent &
develop into new individuals
 Ex- bread mold
Asexual Reproduction
4) Regeneration
 Develop of entire new organisms from
part of parent
 Ex – starfish – develop from single arm
 Also refers to replacement of lost
structures
 Ex – lobster regenerates a lost claw
Asexual Reproduction
 Invertebrate
animals possess more
undifferentiated cells than vertebrates
 Means that invertebrates can
regenerate easier than vertebrates
Asexual Reproduction
5) Vegetative propagation
 New plants develop from roots, stems,
leaves of parent plant
Asexual Reproduction
 Cuttings
– Geranium
 Bulbs – Onion
 Tubers – Potato
 Runners – Strawberries
 Grafting – Seedless Orange