Transcript Chapter 5 Section 4

5.4 Asexual Reproduction
KEY CONCEPT
Many organisms reproduce by cell division.
5.4 Asexual Reproduction
Objectives
• Compare and contrast binary fission and mitosis.
• Describe how some eukaryotes reproduce through
mitosis.
5.4 Asexual Reproduction
Vocabulary
• Asexual Reproduction
– Process by which offspring are produced from a single
parent; does not involve the joining of gametes.
• Binary Fission
– Asexual reproduction in which a cell divides into two
equal parts.
5.4 Asexual Reproduction
Binary fission is similar in function to mitosis.
• Asexual reproduction is the creation of offspring from a
single parent.
– Binary fission produces two daughter cells genetically
identical to the parent cell.
parent cell
– Binary fission occurs in
prokaryotes.
DNA
duplicates
cell begins
to divide
daughter
cells
5.4 Asexual Reproduction
• Environment determines what form of reproduction is most
advantageous.
– Asexual reproduction is
an advantage in
consistently favorable
conditions.
– Sexual reproduction is
an advantage in
changing conditions.
5.4 Asexual Reproduction
Some eukaryotes reproduce through mitosis.
• Budding forms a new organism from a small projection
growing on the surface of the parent.
Hydra
bud
Yeast
5.4 Asexual Reproduction
• Fragmentation is the splitting
of the parent into pieces that
each grow into a new
organism.
• Vegetative reproduction
forms a new plant from the
modification of a stem or
underground structure on
the parent plant.
5.4 Asexual Reproduction
Question/Answer
• How is asexual reproduction an advantage in some
conditions?
– Asexual reproduction produces genetically identical
offspring that are well suited to their environment.
• How might the asexual reproduction of genetically
identical plants be useful to humans? How could it prove
harmful to our food supply?
– Since asexually reproduced plants are clones, we can
theoretically grow a particular plant in abundance
under certain conditions. However, if conditions
change, a significant portion of our food supply could
be adversely affected.