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The Differences Between Asexual and Sexual Reproduction

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									    The Differences Between Asexual and Sexual Reproduction

As you read over the material, use the provided words and phrases to compare and contrast
                             asexual and sexual reproduction.


      Organisms need to make more organisms like themselves through
reproduction. Reproduction is the production of offspring or new individuals
through a sexual or asexual process. In a nutshell, reproduction is the
creation of new individuals from previously existing organisms. Most
organisms reproduce sexually which includes fertilization of an egg and
sperm, but a few do reproduce asexually without fertilization of an egg and
sperm.

      Asexual reproduction is the simplest form of reproduction, occurring
in many simple plants, animals, bacteria, protest, fungi, and micro-organism.
In asexual reproduction there is only one parent. The result of asexual
reproduction is an offspring that is identical to the parent. It can be
considered a clone of the parent because it has the exact same genetic
information as the single parent.

        Example of asexual reproduction is binary
fission in bacteria as seen to the right. In binary
fission one cell divides to form two identical cells. A
cell first duplicates its genetic material and then
divides into two separate cells. Each new cell has its
own complete copy of the parent’s genetic information. An advantage of
asexual reproduction is that an organism can reproduce by itself and it can
occur rapidly. Asexual reproduction can lead to rapid population growth of a
species.

                          Another example of an organism that reproduces
                   asexually is the hydra as seen to the left. The hydra uses
                   a form of asexual reproduction called budding. In budding
                   part of the parent develops into a new organism. The new
                   organism then pinches off from the parent and lives
                   independently. The new organism is genetically identical
                   to its parent. A disadvantage to asexual reproduction is
that only clones are reproduced – there is no genetic variation. An organism
would not be able to adapt and evolve to a changing environment.
      The flatworm Planaria can also reproduce asexually
by fragmentation. In this form the body of the parent
breaks into two distinct pieces, each which can produce
and offspring.




       Majority of animals such as humans reproduce by sexual reproduction.
In sexual reproduction, two parents combine their genetic material to
produce offspring that are genetically different from both parents. Genetic
material from the parents is transferred in a special cell called a sperm for
the male and an egg for the female.
When the egg and the sperm join
together it is called fertilization. During
fertilization, the egg and sperm combine
their single sets of chromosomes to
form a zygote containing two sets, or
the diploid number, of chromosomes for
a species (half from each parent).

       With sexual reproduction the
offspring receives half of its genetic
material from its father and half of its genetic material from its mother.
However, the mitochondrion DNA is received solely from the mother. An
advantage of sexual reproduction is genetic variation. With genetic variation
an organism has a higher chance of adapting and evolving with a changing
environment. A disadvantage of sexual reproduction is that two organisms
are involved.

								
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