1. 7th Science Cells and Heredity
U2L3 – Sexual and Asexual Reproduction

2. Types of Reproduction:
Asexual Reproduction
* new organisms from one parent
* DNA of offspring is identical to DNA of
parent.
Sexual Reproduction
* sex cells from two parents combine
* DNA of offspring is different from either

3. Examples of Asexual Reproduction
Vegetative Reproduction
* grow off of parent plant
or sprout to form new plant
*runner – above ground stem
(strawberry)
*tubers – underground stem
(potato)
*plantlets – tiny plants that grow
along edges of plant leaves
Strawberry runners -
Vegetative reproduction of a potato – you can try this at home! -

4. *Division of parent organism into 2 parts
Binary Fission
*Division of parent organism into 2 parts
* ex. Bacteria, Paramecium (Protist)
*Type of reproduction of prokaryotes
Binary fission -

5. * small, exact copy of adult grows from body of parent
Budding
* small, exact copy of adult grows from body of parent
* ex. Hydra, yeast
Budding yeast -
Buding hydra -
OPTIONAL – SciShow – Hydras: Our Immortal, Tentacled Friends -

6. * whole new organism grows from each piece of parent
Regeneration
* whole new organism grows from each piece of parent
* ex. Sponge, sea stars, planaria (flatworm)
* regrowing damaged or lost body parts
Sea Star regenerating -

7. * specialized cell that can survive harsh conditions
Spore
* specialized cell that can survive harsh conditions
* light; carried by wind
* ex: fungus, fern
Exploding puffball -

8. Sexual Reproduction
Two sex cells (egg and sperm) come together – process called fertilization.
Sperm – formed in male reproductive organs
Egg – formed in female reproductive organs
-- much larger & contains food material
New cell formed by
fertilization is called
a zygote
Read and do pg. 116

10. Advantages of asexual reproduction
Organism can reproduce quickly
Offspring are identical to parent, to any favorable traits are passed on
Parent does not need to find a partner
All offspring can make more offspring (not just females)

11. Advantages of sexual reproduction
Increases genetic variation
Offspring have different traits than their parents
Especially important if the environment changes
Advantages of using both!
SciShow “Why Sex?” – STOP AT 4:25
Answer the question – “Why do MOST organisms use sexual reproduction and not asexual?”
Read page 119

12. Write this question in your notebook:
“Why do MOST organisms use sexual reproduction and not asexual reproduction?”