1. Unit A – Biological Diversity
How do species become varied?
Do animals and plants reproduce the same ways?
Are there other ways that a species can be varied?

2. Asexual and Sexual Reproduction
Reproduction produces new individual species. The way a species reproduces determines how much variation the new individual will have.

3. Outcomes
5. distinguish between sexual and asexual reproduction, and identify and interpret examples of asexual and sexual reproduction in different species, by looking at examples found in the environment
11. compare sexual and asexual reproduction, in terms of the advantages and disadvantages 

4. Asexual Reproduction
Asexual reproduction involves only one parent. It is literally without sex.
All offspring are identical to the parent because there is no change in DNA.
There are 4 different types that we will look at
Binary Fission
Budding
Spore Production
Vegetative Reproduction

5. 1) Binary Fission
What? The cell splits into two cells and each one is identical
Who? Single-celled organisms such as bacteria, amoeba, and algae
What is the benefit of this?

6. 2) Budding
What? A parent produces a bud or a small version of itself. The bud will break off or remain attached as a self-sufficient individual—identical to the parent.
Who? Hydra, yeast, and coral
What is the benefit of this?

7. 3) Spore Production
What? Spores are created similar to seeds but only have the DNA of one parent so there is no variation. One parent can produce many spores, each of which will grow into a new individual identical to the parent.
Who? Fungi, green algae, molds, ferns
What is the benefit of this?

8. 4) Vegetative Reproduction
What? It is the reproduction of a plant not involving a seed..
What is the benefit of this?
Runners
What? Long slender stems that grow above the surface
Who? Strawberries, Spider Plants
Cutting
What? Roots grow from the base of the stem into the soil while the shoot continues to grow and produce leaves.
Who? Carnations, geraniums and chrysanthemums

9. 4) Vegetative Reproduction
What? It is the reproduction of a plant not involving a seed..
What is the benefit of this?
Tubers
What? Buds that produce new plants
Who? Potatoes, Sweet Potatoes
Suckers
What? Roots of plants that produce sprouts that create new plants
Who? Cherries, Apples, Blackberries, Dandilions

10. Sexual Reproduction
Sexual reproduction occurs when two individual’s gametes (reproductive cells) combine
The offspring that are produced from this union will have a mix of characteristics (DNA) from the two parents.
What is the benefit of sexual reproduction?
Why are siblings not exactly the same?

11. Sexual Reproduction in Animals
The male gametes are called sperm cells and the female gametes are called egg cells (ova)
When these two gametes unite, it is called fertilization
This combination of the two gametes is called a zygote.
The zygote splits through a process called cleavage and more cells are made
Continued cell division creates a multi-cellular life form called an embryo
This embryo develops inside the female (in most mammals) or outside (like an egg) in others.

12. Sexual Reproduction in Plants
Most plants produce both male and female gametes
Pollen- is the male gamete of a plant
Stamen- male part of the plant where the pollen is found
Ovules- contain the female gametes of the plant
Pistil- the female part of the plant where the ovules are found

13. Continued The gametes unite to produce a zygote
The zygote develops into an embryo
Most embryos in plants are in the form of a seed
Unlike animal embryo’s, plant embryos can remain dormant for a long period of time

14. Continued
Pollination occurs when the pollen is transferred from the anther of the stamen to the stigma of the pistil.
Cross-pollination occurs when the pollen from one plant is carried to the stigma of another plant.
Cross-fertilization occurs when a grain of the pollen forms a long tube which grows down the style into the ovary.
How can this transfer occur?

16. Sexual Reproduction
Sexual reproduction occurs when two individual’s gametes (reproductive cells) combine
The offspring that are produced from this union will have a mix of characteristics (DNA) from the two parents.
What is the benefit of sexual reproduction?
Why are siblings not exactly the same?

17. Advantages and Disadvantages of Asexual Reproduction
Doesn’t need specialized cells or a way of bringing gametes together.
Can produce lots of individuals very quickly
Main disadvantage is that when environments change, all of the organisms will die, because they are not able to adapt to change

18. Advantage and Disadvantages of Sexual Reproduction
Provides lots of variation which helps survive environmental change
Main disadvantage is that this process takes a lot of energy
Some organisms can produce sexually and asexually. How can this be beneficial?
Examples of organisms that can do both
Strawberries – seeds and runners; Carnations seeds and cuttings, and apply trees – suckers and seeds (what is inside your apple?)
Sponges (Yes, they are animals), Jellyfish and starfish (lose a leg, make a new creature!)