Unit a biologicaldiversitynotes(heritability)

1. z Heritability

2. z
Heritable Characteristic:
Passed on from generation to generation.
Non-heritable Characteristic:
Acquired or learned. Not passed on from previous
generations.

3. z
Heritable Characteristic:
Examples:
• eye color
• hair color/type
• skin color
• blood type
• height
Non-heritable Characteristic:
Examples:
• dyed hair color
• sun tan
• ability to play piano
• ability to swim
• language

4. z
Close your eyes
Clasp your hands together above your head, interlocking your fingers.
Clasp your hands together above your head, interlocking your fingers.
Open your eyes. Which thumb is on top?
Try clasping the other thumb on top. Which feels more natural?
Is this discrete variation or continuous?

5. zPTC Paper!

6. zPTC Paper!

7. zPTC Paper!

8. z
The PTC gene, TAS2R38, was discovered in 2003.
There are two common forms (or alleles) of the PTC gene, and at least five rare forms. One of
the common forms is a tasting allele, and the other is a non-tasting allele. Each allele codes
for a bitter taste receptor protein with a slightly different shape. The shape of the receptor
protein determines how strongly it can bind to PTC. Since all people have two copies of every
gene, combinations of the bitter taste gene variants determine whether someone finds PTC
intensely bitter, somewhat bitter, or without taste at all.
PTC Paper!