What is Selective Breeding: Sexual and Asexual Reproduction

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This ppt provides us with information about selective breeding. Selective breeding is the process by which humans use animal breeding and plant breeding to selectively develop particular phenotypic traits by choosing which typically animal or plant males and females will sexually reproduce and have offspring together.
1. Sexual vs. Asexual
2. Compare the results of uniform or diverse
offspring from sexual or asexual reproduction
Uniform offspring
Diverse offspring
Sexual reproduction
Asexual reproduction
3. Sexual Reproduction
 A type of reproduction in which the genetic materials
from two different cells combine, producing an
 The cells that combine are called sex cells
Female – egg
Male – sperm
 Fertilization: an egg cell and a sperm cell join
A new cell is formed and is called a zygote
4. Advantages: Sexual
 Diverse offspring: genetic variation among
 Half of the DNA comes from mom
 Half of the DNA comes from dad
 Due to genetic variation, individuals within a
population have slight differences
 Plants – resist diseases
 Traits can develop to resist harsh environments
that allows an organism survive
5. Advantages: Sexual
Selective Breeding
Used to develop many types of
plants and animals that have
desirable traits
Agriculture/Farming: better
plants, larger animals
Desirable pets
6. Disadvantages: Sexual
Time and Energy
Organisms have to grow and develop until they are old enough
to produce sex cells
Search and find a mate
Searching can expose individuals to predators, diseases, or
harsh environmental conditions
Fertilization cannot take place during pregnancy, which can last
as long as 2 years for some mammals.
7. Examples: Sexual Reproduction
8. Asexual Reproduction
One parent: organism produces
offspring without fertilization
Uniform offspring:
Because offspring inherit all of
their DNA from one parent, they
are genetically identical to each
other and to their parent
9. Fission: Asexual
 Fission: Cell division in prokaryotes that forms two
genetically identical cells
 DNA is copied
 The cell begins to grow longer, pulling the two
copies apart
 The cell membrane pinches inward in the middle
of the cell
 Cell splits to form two new uniform, identical
 Examples: bacteria, Ecoli, pond critters
10. Budding: Asexual
 Budding: a new organism grows by mitosis and
cell division on the body of its parent
 The bud, or offspring is identical to the parent
 The bud, when large enough, can break off of
the parent and live on its own
 Offspring may remain attached and form a
 Examples: Yeast, Hydra, cactus
11. Regeneration: Asexual
 Regeneration: occurs when an offspring
grows from a piece of its parent.
 Producing new organisms: Sea Stars
Sea urchins, sea cucumber, sponges,
and planarians
 Producing new body parts: Gecko
Newts, tadpoles, crabs, hydra, and
zebra fish
12. Vegetative Propagation: Asexual
 Vegetative Propagation: uniform offspring
grow from a part of a parent plant
 Parent plants sends out runners
 Where the runner touches the ground, roots can
 A new plant is produced even if the runner is
broken apart
 Each new plant is uniform and identical to the
 Examples: strawberries, potatoes, ivy, crabgrass
13. Advantages: Asexual Reproduction
Enables organisms to reproduce
without a mate
No wasted time and energy
Enables some organisms to
rapidly reproduce a large number
of uniform offspring
14. Disadvantages: Asexual
Because their offspring are identical, there is no
genetic variation that can give an organism a
better chance for survival
Example: If a weed killer can kill the parent, it
will also kill the offspring
A whole species can be wiped out from a disease
Dangerous mutations in DNA – if the parent
has the mutation in their DNA, the offspring will
have it too.
15. Examples: Asexual Reproduction
16. Activity:
 Create a creature that reproduces asexually.
Draw the creature
Describe how the creature reproduces asexually
Describe 1 advantage of reproducing this way
Describe 1 disadvantage of reproducing this way
Name your creature
How the uniform offspring of your creature