Transcript Reproduction: Asexual vs. Sexual

Reproduction:
Asexual vs. Sexual
Reproduction is
important for the
survival of all living
species.
Without a
way to
reproduce,
life would
come to an
end.
Two types of
reproduction:
Asexual
reproduction
involves only one
parent & results
in an exact
duplicate of an
organism.
There are many types of
asexual reproduction.
(budding, binary fission,
fragmentation,
regeneration, spores,
cloning, etc…)
Sexual
reproduction
involves the
joining of male
& female sex
cells, called
gametes.
The male’s sperm &
female’s egg are joined
in a process called
fertilization & results in
the production of a
zygote.
Advantages &
disadvantages
of each type
of
reproduction:
Asexual
Reproduction
1. Asexual
reproduction is
common among
plants, single-celled
organisms & simple
animals.
2. Asexual
reproduction
requires only
one parent.
3. Asexual
reproduction has
the advantage of
producing large
numbers of
offspring very
quickly.
4. The offspring produced
by asexual reproduction,
from the same parent, are
identical to one another &
they are identical to the
parent (clones) which
prevents adaptations from
occurring.
5. If a species
of organism
shows no
variation &
cannot adapt it
may become
extinct.
Sexual
reproduction
1. Sexual
reproduction is
common among higher
animals & flowering
plants.
2. Sexual
reproduction requires
sex cells produced by
two parents. (sperm
from males & eggs
from females)
3. Sexual
reproduction is
more complex &
slower than asexual
reproduction.
4. The offspring produced
by sexual reproduction
have genetic variation.
They may look like their
parents, but they are not
identical.
5. Amongst populations of
wild animals & plants,
individuals show variation
as a result of sexual
reproduction. This variation
allows them to adapt to
the environment.
Sexual
Asexual
Sexual
reproduction
Asexual
always
reproduction
requires
does not require
Definition
fertilization
fertilization so
so it requires
only one parent
the sex cells
is involved.
of two
parents.
Sexual
Advantages
Asexual
The offspring will be
different from its
parents. This variation Asexual reproduction
allows the species to
is usually faster and
adapt to its
easier, so a new plant
surroundings.
or animal can colonize
an area more quickly.
“Good” traits are
passed on and
A mate does not have
strengthen the species to be found so no travel
which increases their is involved which saves
survival rate.
energy.
The fertilized egg
Less complex and
more reliable.
(zygote) can sometimes
survive in adverse
conditions (drought).
Sexual
Disadvantages
Asexual
The new organisms
are genetically
identical to their
Often slower than
parents. (they will all
asexual
look exactly the
reproduction, more
same as each other).
complex, and less
Organisms with no
reliable.
variation that cannot
adapt it may become
extinct.
Sexual
Examples
Asexual
Plants that make spores
(moss, ferns).
Fungi make spores (mold,
mushrooms).
Most animals reproduce
sexually (fly, human, snake,
Single cells, which
frog).
reproduce by binary fission
All flowering plants and
or splitting in two (amoeba,
bacteria).
those that make seeds
reproduce sexually.
Budding (spider plant,
hydra).
(daffodil, grass, rose, oak
tree).
Runners (grass,
strawberries).
Fragmentation (planarians).
Regeneration (starfish).
Examples of
Asexual
Reproduction:
Spores: Ferns, mosses
molds & mushrooms
produce spores which
are dispersed, then
under favorable
conditions a single
spore develops into a
new individual.
Spores
Binary fission:
Amoebas, bacteria
and other singlecelled organisms divide
to form two identical
cells that become the
same size.
Binary fission
Budding: Some bacteria,
plants, fungi, yeast,
sponges, corals and hydras
form new organisms when
part of the parent breaks
off to form a daughter cell
that grows into a new
individual that is identical
to the parent.
Budding
Runners: Potatoes,
strawberries, some grasses
and other plants can form
horizontal stems that grow
on top of or just below the
ground which can produce
new plants horizontally at
nodes or tips along the
stem.
Runners
Fragmentation: Some
plants, planarian and
other worms can be
split into many
fragments that each
grow into new
identical individuals.
Fragmentation
Regeneration: Type
of fragmentation in
which starfish,
lizards & sponges
can grow back body
parts that are
damaged or lost.