1. Asexual reproduction verses sexual Reproduction
Two types of Reproduction

2. Asexual Reproduction
a type of reproduction by which an offspring forms from a single organism and inherits its DNA from only one parent
organism produces offspring without fertilization
Offspring are genetically identical to each other and to their parent

3. Fission
Fission: Cell division of prokaryotes (no nucleus) 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 identical offspring
Examples: bacteria, Ecoli, pond critters

4. Budding
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 colony
Examples: Hydra, Cactus,Yeast
HYDRA

5. Budding- Examples
Hydra Budding
offspring
Cactus Budding

6. Budding example
In yeasts the cell does not divide equally in two halves; instead, there is a large mother cell and a smaller daughter cell.
Yeast budding

7. Regeneration/Fragmentation
Regeneration: occurs when an offspring grows from a piece of its parent through mitosis.
Producing new organisms: Sea Stars
Sea urchins, sea cucumber, sponges, and planarians
Producing new body parts: Gecko
Newts, tadpoles, crabs, hydra, and zebra fish

8. Fragmentation
In this form, the body of the parent breaks into distinct pieces, each of which can produce an offspring.
Pieces of coral broken off in storms
can grow into new colonies.
A new starfish can grow from
one detached arm.

9. Fragmentation- plant cuttings
Some plants can grow from cutting them up and replanting them.

10. Vegetative Propagation: Asexual
Vegetative Propagation: uniform offspring grow from a part of a parent plant through mitosis
Parent plants sends out runners
Where the runner touches the ground, roots can grow
A new plant is produced even if the runner is broken apart
Each new plant is uniform and identical to the parent.
Examples: strawberries, potatoes, ivy, crabgrass

11. Asexual Reproduction Review Video
Instructional Approach(s): The teacher should show the video to reinforce the concepts of reproduction.

12. How does sexual reproduction cause offspring from the same parents to be genetically different? L.8.2A.4
Performance Objectives:
Engage in discussion using models and evidence to explain that sexual reproduction produces offspring that have a new combination of genetic information different from either parent. .
This objective will be developed further in L.8.2.C.1 The purpose here

13. Sexual Reproduction
New organisms is produced from the combined DNA of TWO different cells called sex cells or gametes.
Sex cells are formed by the process of Meiosis
Male is called sperm & Female is called egg
Examples
Humans, some plants, mammals, fish, reptiles, etc.

14. Embryo

15. Examples: Sexual Reproduction

16. Fertilization
Fertilization occurs when an egg and sperm unite to form a new organism with half of each parent’s DNA
The fusion of a sperm and egg form a zygote

17. Fertilization

18. What are advantages & disadvantages of sexual & asexual reproduction? L.8.2A.5
This objective will be developed further in L.8.2.C.1 The purpose here
Performance Objectives:
Compare and contrast advantages and disadvantages of asexual and sexual reproduction.

19. Advantages: Sexual Reproduction
Diverse offspring: genetic variation among offspring
Half of the DNA comes from mom
Half of the DNA comes from dad

20. Due to genetic variation, individuals within a population have slight differences due to genetic recombination during MEIOSIS
Plants – resist diseases
Traits can develop to resist harsh environments that allows an organism survive
Able to ADAPT to changes in the environment

21. Advantages: Sexual Reproduction
Selective Breeding
Used to develop many types of plants and animals that have desirable traits
Agriculture/Farming: better plants, larger animals
Desirable pets

22. Disadvantages: Sexual Reproduction
SLOWER: 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

23. Fertilization cannot take place during pregnancy, which can last as long as 2 years for some mammals.
LESS offspring produced at one time

24. Advantages: Asexual Reproduction
Does NOT require special cells
Enables organisms to reproduce without a mate
FASTER: No wasted time and energy
Enables some organisms to rapidly reproduce a large number of uniform offspring

25. Disadvantages: Asexual Reproduction
Because their offspring are identical, there is very little to 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

26. High risk of EXTINCTION if environment changes
Dangerous mutations in DNA – if the parent has the mutation in their DNA, the offspring will have it too.