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
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
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 protists to 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 outisde in 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)
Ovules contain 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
Pollination occurs when pollen is transferred from the anther of
the stamen to the stigma of the pistil.
Fertilization occurs when the male and female gametes unite
Cross-Pollination occurs when the pollen of one plant is carried
to the stigma of another by wind, water, or animals, such as
bees or butterflies
Cross-fertilization occurs 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