Aim
How and why do
organisms
reproduce?
Why do organisms Reproduce?
• Reproduction
is necessary for
continuation of
the species.
Types of Animal Reproduction
• Asexual
( 1- parent)
• Sexual
(2-parents)
Asexual Reproduction
• Binary Fission
• Budding
• Fragmentation
(Mitosis)
Binary Fission
Parent has 4
chromosomes
4
4
4
Each offspring also
has 4 chromosomes
• The separation
of one parent
into two or
more
individuals of
approximately
the same size
(Mitosis)
Binary Fission in amoeba
Budding
• Process in which
an offspring is
produced by the
outgrowth of an
existing parent
Yeast
(Mitosis-identical
replication)
Budding in yeast
Fragmentation
• Is the breaking
of a body piece
which develops
into a exact
complete adult
Starfish
Cloning
• From one parent
• Creates identical
genetic copies
• Mitosis
• Cloning has been
accomplished with
sheep and pigs
Sexual Reproduction
• It involves two
parents that
produces offspring
that are not
identical to parent
• DNA comes from
Mom and Dad
Sperm and Egg
• Sexual
reproduction
involves the fusion
of sperm and egg
• Sperm or egg is
also referred to as
gametes
Fertilization
Gametes
• Male gameteSperm
• Female gameteEgg
Asexual reproduction of organisms normally
results in new organisms that contain cells with
1.more chromosomes than are found in the cells
of the parent
2.half the number of chromosomes
3.the same number of chromosomes
4.fewer chromosomes that are found in the cells
of the parent
The diagrams represent a cell process. If the cell in
Diagram 1 contains 4 chromosomes, what is the
total number of chromosomes in each cell in
Diagram 3?
1.8
2.2
3.16
4.4
Which phrases best identify characteristics of asexual
reproduction?
1.one parent, union of gametes, offspring similar to
but not genetically identical to the parent
2.one parent, no union of gametes, offspring
genetically identical to parents
3.two parents, union of gametes, offspring similar to
but not genetically identical to parents
4.two parents, no union of gametes, offspring
genetically identical to parents
One way to produce large numbers of
genetically identical offspring is by
1.cloning
2.fertilization
3.changing genes by agents such as
radiation or chemicals
4.inserting a DNA segment into a
different DNA molecule