Transcript REPRODUCTION

The continuity of life…
 Reproduction
is the process by which
organisms produce more of their own
kind…can be sexually or asexually
 Think
about it…Without it…all life on
earth would cease to exist
ASEXUAL REPRODUCTION
SEXUAL REPRODUCTION
ASEXUAL
Characteristic
Requires ONE
parent.
NO sex cells,
NO fertilization
Advantage/Disad Do NOT have to
vantage
find mate
Offspring have
NO variation
Offspring are
genetically
identical to
parent cell
SEXUAL
Characteristics
Requires TWO
parents
Involves TWO
sex cells
Requires
fertilization
Advantages/Disa Requires mate
dvantages
Offspring have
variation
Offspring are
NOT genetically
the same
Offspring are
combination of
BOTH parents
 Binary
Fission…
 Budding…
 Spore production
 Regeneration
 Propagation
• Vegetative
• Artificial
 Parthenogenesis


The nucleus divides
by mitosis and the
cytoplasm divides,
forming 2 new
daughter cells of
equal size.
Occurs in single
celled organisms
…bacteria,
protists…amoeba,
paramecium

The division of cytoplasm is unequal so one of
the daughter cells is larger than the other.
The daughter cells can separate or remain
attached.
New Organisms Arise
as an Outgrowth from
the Parent Organism
 Seen Mostly in Marine
Animals

• Examples Include;
Sponges, Corals and
Jellyfish…

Also seen in yeast and
Hydra
Coral Polyp Photo courtesy Jeffrey N. Jeffords
http://oceanworld.tamu.edu/students/coral/coral1.htm
Spores are produced in
large numbers by
mitosis.
 Spores are surrounded
by a tough coat to help
them survive harsh
environmental
conditions.
 Seen in mosses,
fungi…mushrooms,
molds

This refers to the
ability of some
animals to re-grow
severed parts.
 Some of these animals
can also grow new
organisms from the
severed pieces
 Segmented Worms
and Sea Stars

VEGETATIVE
 New plants
develop from the
roots, stems, or
leaves of the
parent plant.
 Three Types
• Tubers
• Bulbs
• runners
Tubers are underground
food stores which stores
food over the winter and
provides a new plant with
food until it can make its
own.
Examples: potato,
artichoke, yam, water
chestnut, arrowroot
TaroJapanese
potato
Food made by the new plant
is sent to make new tubers.
Thereby reproducing itself.
 E.g.
daffodils, lilies
Runners are side shoots
which grow out from the
parent plant.
Buds form at points along
the runner and eventually
these buds form roots and
grow into new plants.
Examples: spider plant
(Anthericum), strawberry
(Fragaria x ananassa)
Artificial
 With plants, but
with human
intervention
 Two main types
• Cuttings
• Grafting
Cuttings are small pieces of stem with some
leaves attached, the new plant grows from this.
They can be placed in moist
soil or water (and sometimes
dipped in rooting
powder).
A cut stem of one plant (with good flower or
fruit growth) (the graft) is taken and firmly
attached to the rootstock of another plant
(which has a strong, established root system)
(the stock).
Examples- roses, fruit trees
Offspring can arise
from unfertilized eggs.
 Includes some Fish,
Reptiles, Amphibians
and Aphids.
 Most of these species
can switch between
Sexual and Asexual
Reproduction.

http://aolsearch.aol.com/aol/imageDetails
?invocationType=imageResults&query=ph
otos+of+parthenogenic+species&img
http://www.duke.edu/%7Ejsr
6/Hawaiipics/Rhampho.jpg
(depending on conditions)
http://spot.colorado.edu/~noyesr/TEACHIN
G/4800%20Fall%202002.%20Biology%20an
d%20Evolution%20of%20Sex/Gynogenesis.
Poecilia.pdf
www.ag.ndsu.nodak.edu