Heredity

2. variation helps the species as a whole to _____ to the environment.
3. a source of variation
8. chemical substances or physical processes which can bring about process in clue 3.
10. in continuous variation, there is a _____ of traits.
11. defective trait resulting from variation involving haemoglobin molecule.
12. the parts of the chromosome responsible for determining traits.
13. discontinous variation is controlled by one or ___ gene.

1. reason for variation in clue 9:______ assortment
2. where the process is aided by man
4. where natural selection takes place
5. defective syndrome caused by an extra chromosome 21.
6. where process in clue 3 must take place for variation to be transmitted to the next generation.
7. selection always results in a ___ of genetic material
9. another source of variation that involves the fusion of two gametes.