1. TOPIC 3: Passing It On
Everywhere you look, there are examples of organisms that look just like their parents.
How does this happen???

2. Reproduction Is ONE of the characteristics of living things
Is ESSENTIAL to the survival of the SPECIES but NOT the INDIVIDUAL
Reproduction can be either sexual or asexual

3. How are traits passed on?
Traits are said to be inherited or heritable and are passed on in the genetic material (DNA)

4. Asexual Reproduction DEFINITION:
Asexual reproduction occurs when only one parent supplies the information to the offspring
A formation of a new individual from a SINGLE organism

5. Inherited traits are like the parents
OFFSPRING LOOKS LIKE:
Inherited traits are like the parents
Looks IDENTICAL to the parent
ORGANISM EXAMPLES:
Common among bacteria and fungi

6. ADVANTAGES:
No energy wasted in finding a mate
Does not require a specialized cell or way of getting the gametes together
Can occur rapidly (bacteria-20 min)
Large numbers
Good only in that type of environment

7. DISADVANTAGES:
Cannot survive if the environment changes
NO variation among species

8. Types of asexual reproduction
Binary Fission
Spore reproduction
Budding
Vegetative reproduction

9. Binary fission
Many one celled organisms such as the amoeba reproduce asexually by binary fission.
Binary fission: the first cell duplicates its organelles and then splits creating a second organism with a copy of the same genetic material

10. Asexual Spores
Some fungi and mushrooms can reproduce asexually using spores.
Spores are single celled, reproductive structures
Usually spores are produced in high numbers to ensure at least some survive
Some other algae produce zoospores which move with a tail-like structure

11. Budding
In budding, an organism will grow a new group of cells near its base (BUD) and then the ____bud_____________detaches as a new growth to start a new organism
b. Examples: Sea sponge

12. Asexual reproduction in Plants
Plants don’t produce spores, but they still reproduce asexually.
1. Meristem
Meristem cells are able to repair damage to the plants
Meristem cells are also used for ‘cuttings’ when planting new plants.
2. Runners and suckers
Runners are sent out by strawberry plants above ground
Suckers are sent out by poplar trees and lilacs above or below ground

13. 3. Tubers 4. Bulbs Potatoes and yams When they are put into the ground
they will grow a new plant
4. Bulbs
Onions and daffodils
When put into the ground they will grow a new plant
reproduction-vegetative-propagation-and-bulbs.html

14. Asexual plants – clones????
In asexual reproduction in plants, the offspring are clones (exact copies) of the parent.
You may recall Dolly the sheep. She was the first organism to be successfully cloned.
What do you think about cloning?

15. Sexual Reproduction Definition: Offspring Looks like?
Reproductive process involving two sexes or mating types and resulting in a combination of genes
Offspring Looks like?
Both parents supply genetic material so the offspring will display a combination of both parents

16. Organism Examples: Advantages: Disadvantages: Plants, Animals
Get a variety of living things
Disadvantages:
Takes a lot of energy
Needs to provide a way for gametes to meet
Protect and nurture young
Limited offspring

17. Sexual Reproduction in Plants
Pistil – female reproductive part of the plant
Consists of the ovary, style and stigma
Stamen – male reproductive part of the plant
Consists of the anther and filament
Ovule – contains the female gamete
Anther – contains the male gamete

18. Steps of Pollination 1. Pollen gets stuck to the stigma
2. Pollen tube grows to the ovule 3. Pollen grain (sperm)
Travels to the ovule to fertilize egg 4. Zygote is formed and it undergoes many cell divisions to form an embryo
5. Embryo is supplied with food by one or two cotyledons - seed

21. Sexual Reproduction in Plants
Plants have diverse reproductive strategies
35,000 spore bearing
700 species are gymnosperms (produce seeds in cones)
200,000 species of angiosperms (flowering plants)
Some are self pollinating and some are cross pollinating

22. DEFINITON
ADVANTAGES
DISADVANTAGES
Self Pollination - male and female gamete comes from the same plant
Ensures pollination and SURVIVAL
Obtain an “pure breed” or clone
-No variation to survive in an ever changing environment
Cross Pollination
- Male and female gametes come from different plants
Allows for variation and survival in the ever changing environment
- Less chance to get pollinated (needs insects)

23. Avoiding Self Pollination
Stamen and pistils mature at different times
Stamen is shorter than pistils
Wind-pollinated flowers usually bear the pistil and stamen in separate flowers
Some have pistil and stamens on different parts of the same plant (corn)

24. Sexual Reproduction in Animals
For sexual reproduction to be successful:
Male and female gametes must arrive at the same time at the same place
Zygote requires specific conditions to develop nutrients
Moisture
Warmth and Protection

25. Unite to form a ZYGOTE (a fertilized egg)
What happens? ).
Sexual reproduction combines:
TWO _________________________ (sex cells = sperm, egg) to form
ONE _________________________ (fertilized cell = a new individual
A male sex cell is called a
SPERM
A female sex cell is called an
EGG
Unite to form a
ZYGOTE
(a fertilized egg)

26. Bacterial Conjugation
Bacterial Conjugation is a PRIMITIVE form of sexual reproduction.
Two parents are still involved.
In bacterial conjugation,
a connection is formed between
two cells.
A one-way transfer of genetic
material from one cell to another
can then occur

27. EXTERNAL FERTILIZATION - Most worms, many fish, and amphibians
Sperm meets the egg outside of the body
Moisture is needed for the sperm to swim
Lots of energy is spent to produce large numbers of eggs and sperm
INTERNAL FERTILIZATION
-Insects, reptiles, birds, mammals and some fish and amphibians
- Sperm meets the egg inside the body - Reduces the harsh climate and predators
Provides a moist environment for the sperm to swim
Smaller number of sperm and eggs needed

28. Interesting Tid-Bits Monotremes are mammals that lay eggs.
Ie: Platapus and spinny anteater

29. Hermaphrodites can produce both egg and sperm
Individuals can change their sex over time
The female opossum gives birth to offspring that are smaller than a honeybee.