2. Genetics

3.  The members of this family tree are related and so they share certain similar characteristics. So why don’t all family members look exactly alike?

4.  People are similar, but not identical, to their parents or each other. The differences in a species are called variation.  Variation can come about for two reasons. What are they?

5.  People inherit characteristics from both of their parents These are called inherited variations.  Other characteristics are affected a person’ surroundings. These are called environmental variations.

7.  Can you think of other environmental and inherited variations? EnvironmentalInherited

8.  How does a builder know what kind of building to build?  How does grandma know how to work the DVD player?

9.  How do our eyes know to be blue?  How do our heart cells know to keep beating?

10.  Genetic material (DNA) contains the instructions used by living things.  Genetic material is found in the nucleus of cells.

11.  If we look closer into the nucleus we can actually see the genetic material as chromosomes.  Although chromosomes appear short and fat, they are actually very long strands that are tightly coiled.

13.  When we look closer still, we find that chromosomes are complex structures made of molecules of deoxyribonucleic acid (DNA ).

14.  DNA contains all the information required to build a living organism.  Each chromosome is made up of two long DNA molecules.  The two molecules are twisted around each other forming a double helix.

15.  Within the long strands of DNA we find genes.  A gene is a section of the DNA that contains the code for a specific inherited trait.  Every person is unique because they have different combinations of genes.

16.  An allele is an alternative form of a gene.  Person #1 may have the Brown allele of the eye colour gene.  Person #2 may have the Blue allele of the eye colour gene.

17.  Karl’s DNA  Holly’s DNA Eye Colour Gene

20. TraitMEMumDad Class Total Tongue Roller Non Tongue Roller Attached Ear Lobe Free Ear Lobe Cleft Chin Flat Chin Hitchhikers Thumb Straight Thumb Widows Peak Straight Hairline Right Handed Left Handed