Transcript Asexual Reproduction - School District 67

Asexual
Reproduction
Pg 364-367
Introduction
 Mitosis is the basis for reproduction by
one parent  asexual reproduction
 Common in microorganisms, plants,
fungi, and some animals
 All offspring identical to parents
(including DNA) and each other called
clones
Budding and Binary Fission
 Budding: offspring begins as growth
(bud) on parent
 When it can survive on its own, the bud
detaches
 Unequal division of parent organism
 Eg: yeast, hydra
 Yeast
Hydra 
Binary Fission
 Organism divides into two equal cells
 Parent is lost in the process
 DNA copied, cells divide
 What process is this similar to?
 Eg: bacteria and protists
Asexual reproduction by binary fission
New individuals
(Paramecium)
Amoeba binary fission
•A single bacteria cell can reproduce every 20 minutes
•Over a 12 hour period a single bacterium can produce
10 million copies of itself
Which of the following is Budding?
Which of the following is Binary Fission?
DRAW THE
ANSWERS !!
Fragmentation
 Fragments of the parent break off and
grow into new individuals
 Can occur by accident or purposely
 Eg: planaria
Regeneration
 Re-growing a lost body part or limb
 Usually occurs only if central part of body
is intact
 Eg: salamanders, starfish, crabs
Spore formation
 Parent produces spores, which often
have protective covering
 When conditions are good, they develop
into new organism
 Eg: plants, algae
Asexual reproduction
in plants
Grafting
 Used to propagate a desired variety of
shrub or tree
 Take a scion (twig) and insert into stock
(cut stump)
 Eg: all apple trees
Vegetative reproduction
 Runners: plant sends out aboveground
stems
 New plant grows at end of runner
 Eg: strawberry plants
Vegetative reproduction
 Other plants produce thickened
underground stems
 Rhizomes, bulbs, tubers (storage)
 Eg: asparagus, tulips, ginger
Vegetative reproduction
 Leaves can also form new plants
 Eg: jade plant
 Some plants use roots for asexual repro
 Eg: aspen trees, dandelions
Outcomes of asexual repro
 Genetically identical offspring = clones
 When is asexual reproduction beneficial?
 -when a organism must reproduce
quickly
 -when the environment is unchanging
 -when a mate is hard to find
 What happens when the environment is
not predictable?
Homework
 Review 16.2 #1-7
 Read pages 367-372…tomorrow’s topic