GO 2_2 Asexual and Sexual Reproduction.ppt

A

1. 2.2 Asexual
and Sexual
Reproduction
G.O.2: As species reproduce. Characteristics are passed from parents to offspring.

3. Reproduction
Reproduction produces new individuals of a species.
The way a species reproduces determines how much
variation the new individuals will have.
Reproduction can produce new individuals that are identical
to or very different from one another
Asexual Reproduction –involves one individual, all of the
offspring are identical to that parent
Sexual Reproduction –usually involves two individuals, the
offspring will have a mix of characteristics from both parents

4. Asexual Reproduction
Type of reproduction with only one parent. Each offspring
is identical to the parent (how is this different than sexual
reproduction?)
Types of asexual reproduction:
Budding
Binary Fission
Spore reproduction
Vegetative reproduction

5. Asexual Reproduction
There are 4 ways that organism reproduce asexually:
1)Binary Fission
2)Budding
3)Spore Production
4)Vegetative Reproduction

6. Asexual Reproduction
Binary Fission: Cell splits in two and produces two identical
organisms.http://www.youtube.com/watch?v=3cD3U2pgb
5w
Budding: parent organism produces a smaller version of
itself (known as a bud). The bud eventually detaches from
the parent and becomes an independent organism which
is exactly the same as the
parent.http://www.youtube.com/watch?v=489CSop00sY

7. Budding sea sponges
Budding tube sponge
Budding barrel sponge

8. Asexual reproduction
Spore production –Spores are like seeds but are produced
by one parent (seeds require two parents). The spore is
identical to the parent.
Mould Spores

9. Spores forming on lichen
Spores forming on a fern
Spore forming bacteria

10. Types of Asexual Reproduction:
4) Vegetative Reproduction –reproduction that does not
involve the formation of a seed
-Many plants reproduce this way, but there is more than one
method of vegetative reproduction
-Each method involves taking a cutting of the parent plant,
which will eventually grow identical to the parent

11. Vegetative Reproduction
Grafting
Runners
Pg. 31
Aspen suckers

12. Sexual Reproduction
Reproduction with two individuals. Most plants and
animals reproduce sexually. The offspring has a mix
of characteristics of both parents.

13. Sexual Reproduction in Animals
Sexual reproduction in animals:
http://www.youtube.com/watch?v=POJAQX760VY&featu
re=fvsr

14. Sexual Reproduction in Animals
General process of animal reproduction is similar (from fungi
to protiststo dragonflies to bears; small details vary)
Involves gametes (sex cells)
Male gametes = Sperm Cell
Female gametes = egg Cell (Ova)
Union of the two gametes during mating is called fertilization
The fertilized cell created is known as the Zygote
The zygote undergoes continuous divisions (cleavage) to create
a multicellular life form called the embryo

15. Sexual Reproduction in Animals
The cell division will take place inside the female (most
mammals) or outisdein an egg (most other animals)
Remember: The embryo is not identical to either parent; it
will have a mix of characteristics from both parents

16. Sexual Reproduction in Animals
Only one of the many sperm cells
surrounding the egg will fertilize the egg.
InfoBit: Hermaphrodites
Common garden worms and slugs are
hermaphrodites. They can produce both
math and female gametes.
Although most slugs and worms usually
prefer to mate with other individuals of
their species, in times of environmental
stress, they can fertilize themselves.

17. Sexual Reproduction in Plants
Sexual reproduction in plants:
http://www.youtube.com/watch?v=FsBQQDg5GIw

18. Sexual Reproduction in Plants
As in animals, sexual reproduction requires the joining of a
male and female gametes to create a zygote, and with
continued division, an embryo
Most plants produce both male and female gametes; some
only produce one or the other
Pollen contains the male gametes (found in the stamen)
Ovulescontain the female gametes (found in the pistil)

19. Sexual Reproduction in Plants
You will need to know all of the structures involved in
plant reproduction.
Stamen
Filament
Anther
Pistil
Stigma
Style
Ovary
Ovule
Sepal
Petal
Receptacle
Pistil

20. Sexual Reproduction in Plants
Pollinationoccurs when pollen is transferred from the anther of
the stamen to the stigma of the pistil.
Fertilizationoccurs when the male and female gametes unite
Cross-Pollinationoccurs when the pollen of one plant is carried
to the stigma of another by wind, water, or animals, such as
bees or butterflies
Cross-fertilizationoccurs when a grain of this pollen produces a
long tube that eventually grows down the style into the ovary that
contains the ovules

21. Asexual Reproduction
Does not require specialized cells
or a way of uniting gametes
Can produce lots of offspring very
quickly
Bacteria: 1 10 million in 12 hr
If conditions become
unfavorable, the entire
population may be wiped out
(because they are identical)
So all 10 million bacteria
could be wiped out by the
same antibiotic
Provides lots of variation which
helps the species survive
environmental change
Takes a lot of energy and time;
means limited offspring can be
produced
Sexual Reproduction

22. Asexual or Sexual
Some species have the ability to reproduce both sexually
and asexually.
In plants, seeds can often be produced sexually and asexually.
If the seeds don’t have a contribution from a sperm cell they
will be genetically identical to the parent (i.e. _____________,
sunflowers, roses)
In animals, aphids, sponges,
__________ and moss can
alternate between asexual
and sexual reproduction