Anthropology 101, 6th Period
Daniel's looking very pleased with himself today. Unless he screws up in the slow play later. But I'm sure he won't
"First off, well done to Han for the interesting presentation yesterday," he said. "Did you enjoy it, Blair?"
"Now. We're moving away from evolution, and onto genetics and inheritance.
Theories of heredity are attributed to Gregor Mendel.
While Mendel's research was with plants, the basic underlying principles of heredity that he discovered also apply to people and other animals because the mechanisms of heredity are essentially the same for all complex life forms.
Through the selective cross-breeding of common pea plants (Pisum sativum) over many generations, Mendel discovered that certain traits show up in offspring without any blending of parent characteristics. For instance, the pea flowers are either purple or white--intermediate colors do not appear in the offspring of cross-pollinated pea plants. Mendel observed seven traits that are easily recognized and apparently only occur in one of two forms:
1. flower color is purple or white
2. flower position is axil or terminal
3. stem length is long or short
4. seed shape is round or wrinkled
5. seed color is yellow or green
6. pod shape is inflated or constricted
7. pod color is yellow or green
This observation that these traits do not show up in offspring plants with intermediate forms was critically important because the leading theory in biology at the time was that inherited traits blend from generation to generation.
Since Mendel's time, our knowledge of the mechanisms of genetic inheritance has grown immensely. For instance, it is now understood that inheriting one allele can, at times, increase the chance of inheriting another or can affect how and when a trait is expressed in an individual's phenotype. Likewise, there are degrees of dominance and recessiveness with some traits.
We'll be working on examples in the next lesson, but for now... any questions? What do you think you've inherited from your parents?
For homework, I want you to learn these two lists of genetic vocabulary. I'll be testing you on a few of them at the start of the lesson on Monday. That's all, thank you guys."
"First off, well done to Han for the interesting presentation yesterday," he said. "Did you enjoy it, Blair?"
"Now. We're moving away from evolution, and onto genetics and inheritance.
Theories of heredity are attributed to Gregor Mendel.
While Mendel's research was with plants, the basic underlying principles of heredity that he discovered also apply to people and other animals because the mechanisms of heredity are essentially the same for all complex life forms.
Through the selective cross-breeding of common pea plants (Pisum sativum) over many generations, Mendel discovered that certain traits show up in offspring without any blending of parent characteristics. For instance, the pea flowers are either purple or white--intermediate colors do not appear in the offspring of cross-pollinated pea plants. Mendel observed seven traits that are easily recognized and apparently only occur in one of two forms:
1. flower color is purple or white
2. flower position is axil or terminal
3. stem length is long or short
4. seed shape is round or wrinkled
5. seed color is yellow or green
6. pod shape is inflated or constricted
7. pod color is yellow or green
This observation that these traits do not show up in offspring plants with intermediate forms was critically important because the leading theory in biology at the time was that inherited traits blend from generation to generation.
Since Mendel's time, our knowledge of the mechanisms of genetic inheritance has grown immensely. For instance, it is now understood that inheriting one allele can, at times, increase the chance of inheriting another or can affect how and when a trait is expressed in an individual's phenotype. Likewise, there are degrees of dominance and recessiveness with some traits.
We'll be working on examples in the next lesson, but for now... any questions? What do you think you've inherited from your parents?
For homework, I want you to learn these two lists of genetic vocabulary. I'll be testing you on a few of them at the start of the lesson on Monday. That's all, thank you guys."