Transcript Asexual Reproduction and Types

Types of Asexual
Reproduction
Reminder:
Meiosis
Mitosis
Forms sex cells (sperm
and eggs)
Responsible for growth,
differentiation, and
asexual reproduction
½ the number of
chromosomes compared to
the parent cell
Genetically
identical to parent
cell
One replication and
two divisions
One replication and one
division
4 daughter cells
formed
2 daughter cells
formed
Asexual Reproduction
• A reproduction method that only needs one
individual
• Involves the process of mitosis.
• Offspring are genetically identical to parent
•Different methods used by different species
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Binary Fission
Fragmentation
Budding
Mitosis
Spore
Regeneration
Binary Fission
• Parent divides into 2 equal halves after
the nucleus replicates
• No parent remains - 2 daughter cells grow
to normal size
• Occurs in bacteria, protozoa, and algae
Budding
• Parent organism divides into 2 unequal
halves
• Daughter cell forms from bud or outgrowth
off parent
• Buds may break off or remain attached
and form a colony
• Occurs in hydra and yeast
Sporulation (spore forming)
• Production of many spores in a special
spore producing structure(spore case)
• Spores are microscopic, specialized
cells, containing nucleus and cytoplasm
within a hard case
• Occurs in molds and ferns
Regeneration
• Ability to grow back missing parts
• The more complex the organism, the
harder it is to regenerate
• Occurs in simple organisms such as
starfish and flat worm
Humans?
Fragmentation
• A piece (hyphae) of the parent breaks
off and is moved to another location
• A new individual develops from this
fragment
• Occurs in fungi (mushrooms)
Vegetative Propagation
• A piece of a body of a multicellular
organism gives rise to a new organism
• Common in plants - using stems, leaves,
or roots
• Can occur naturally or artificially
Natural Vegetative Propagation
• Bulb- Short underground stem with stored food &
fleshy leaves Ex. Onion, tulip
• Corm- Short underground stem with stored food
Ex. Water chestnut
• Tuber- Enlarged underground stem Ex. potato
• Runner- (stolon) horizontal stem with buds along
ground’s surface Ex. strawberry
• Rhizome- Underground horizontal stem Ex.
ginger
Tuber
Runner
Bulb
Rhizome
Corm
Artificial Vegetative Propagation
Cutting- use part of plant to reproduce
(Ex.Spider plant)
Layering- stem is bent over and covered with soil
will root and form new plant (Ex. raspberry)
Grafting- stem or bud of one plant is joined to
another plant permanently (Ex. Seedless fruit tree)
scion
stock
Layering
Grafting
1 Tree 40 Fruits