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. Outcomes
4. identify the role of variation in species survival under changing environmental conditions 
6. describe examples of variation of characteristics within a species
10. distinguish between, and identify examples of, natural and artificial selection and the technology involved

3. Outcomes
identify the role of variation in species survival under changing environmental conditions 
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
describe examples of variation of characteristics within a species
investigate the movement of characteristics from parents to offspring, and identify examples of characteristics in offspring that are:
the same as the characteristics of both parents
the same as the characteristics of one parent
intermediate between parent characteristics
different from both parents
distinguish those characteristics that are heritable from those that are not heritable, and identify characteristics for which heredity and environment may both play a role
identify examples of dominant and recessive characteristics
describe, in general terms, the relationship of chromosomes, genes and DNA; and interpret their role as repositories of genetic information 
distinguish between cell division that leads to identical daughter cells, as in binary fission and mitosis, and cell division that leads to formation of sex cells, as in meiosis
compare sexual and asexual reproduction, in terms of the advantages and disadvantages 
distinguish between, and identify examples of, natural and artificial selection and the technology involved

4. VARIABILITY AND SURVIVAL
Variability is important if the environment of a species changes.
Environmental change can be from humans, adding a predator in, change in climate or the introduction of a new disease.
Example: Peppered Moth

5. VARIABILITY AND RESISTANCE
Variability is good for species to survive environmental changes but it can also be negative for humans when they want to eliminate something.
Certain strains of bacteria have become resistant to antibiotics and if the trend continues antibiotics may no longer be effective.
Can you think of other examples of variability being a negative or positive thing?

6. NATURAL SELECTION
Natural selection occurs when the environment “selects” which individuals within a species will be able to survive long enough to reproduce.
Read page 24
Where else do we see natural selection occur?
Answer question 5 under extend your learning and understanding.

7. Outcomes Describe examples of variation
Identify examples of both discrete and continuous variation

8. Class Exploration
Working in groups, complete the table and test the following features of your group members
Characteristic
Option 1
Option 2
dimples
dimples present
no dimples
eye colour
brown/green
blue/grey
earlobe
detached
attached
hair colour
brown/black
blond/red
second digit finger
short
long
skin pigment
freckles
no freckles
thumb
bends back
does not bend back
tongue
can roll
cannot roll

9. Heritable and Non-Heritable Characteristics
Heritable characteristics are passed down from generation to generation.
These include: structural and distinguishing traits such as eye colour, hair type, skin colour and ear lobes.
Non-Heritable characteristics are acquired by each individual separately and not necessarily passed on from generation to generation.
These can include athleticism, artistic ability, having big muscles, dyed hair

10. Discrete vs. Continuous Variation
Discrete variation are characteristics that only has a few choices, either/or
Example: being able to roll your tongue or not; albino or not
Continuous variation are differences that have a range of forms
Example: height, weight, hair, eye colour

11. Variations and the Environment
Some variations may be influenced by interactions with the environment. These variations are NOT inherited
Example: Height and weight. How is this influenced by the environment?
Example: Changes in pigmentation of skin colour throughout different seasons

12. Review What is a heritable trait? What is a non-heritable trait?
What is continuous variation?
What is discrete variation?

13. Post- It Question
#5 pg 29
A scientist wants to study continuous variation in a mouse population. What mouse characteristics would she/he investigate?

14. 2.2 Asexual and Sexual Reproduction
Reproduction produces new individual species. The way a species reproduces determines how much variation the new individual will have.

15. I Can… Distinguish between asexual and sexual reproduction
Describe organisms that show both sexual and asexual reproduction
Describe the main type of sexual reproduction
Describe the main types of asexual reproduction

16. 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

17. 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?

18. 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?

19. 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?

20. 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

21. 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

22. 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?

23. 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.

24. 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

25. 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

26. 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?

28. 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

29. 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!)

30. To do:
Work through A3B with a partner