A Closer Look at Variation
Variation is described as a different or distinct version of something.
Scientists, in an effort to understand variation, look at the characteristics that are passed on from generation to generation. Genetics are not the only factor that plays a role; the environment in which a species lives can impact it's variation as well.
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Heritable Traits are traits that are passed on from one generation to the next. This means that you have a particular trait because someone in your biological family has had that trait.
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Acquired Traits are traits that are learned over time or are a result of the environment. For example, you can learn to "live long and prosper" Spock style, and you can get a tan by sitting out in the sun for extended periods of time.
Discrete variation is a trait that is distinct; you either have or do not have the trait. For example, you are either albino or not. Continuous variation is something that can change in varying degrees within a species. For example, height is slightly different in individuals most of the time. What exception is there to this "rule"?
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Reproduction
There are 2 types of reproduction that occur naturally in our world:
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Asexual Reproduction
Sexual Reproduction: Plants
Sexual Reproduction of Plants requires 2 parent cells: a male and a female. The plant that is "born" will be a slight variation of it's parent plant.
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Sexual Reproduction: Animals
Section Review (test Wednesday, Oct. 21):
- What is asexual reproduction? What are 4 "types" of asexual reproduction? Explain how a poplar tree would reproduce, using scientific terms, if it uses shoots.
- Label a flow chart demonstrating the process of sexual production, beginning with gametes and ending at offspring. Note the name of processes within your diagram (i.e. What is it called when cells begin to separate). What is this process called?
- Using images, represent how plants sexually reproduce. Where does the zygote of a plant form?
- What is the difference between discrete and continuous variation. Provide an example of the different ranges of continuous variation as well as examples of discrete variation
- Describe the difference between heritable and acquired (or non-heritable) traits. Consider examples.
- In your opinion, what are some advantages and disadvantages of sexual and asexual reproduction (fill in the chart on the back page of your reproduction notes - find info to support your opinion in the Ppt on CampbellCorner as well as the text).
- In your opinion, is it important to pass on characteristics from one generation to the next?