Biology 7.2 Types of variation

Variation due to genetic factors

• Organism fits into a few distinct forms, no intermediate types e.g. blood groups.
• This type usually caused by single gene.
• Environmental factors have little influence.

Variation due to environmental influence

• Some characteristics grade into one another e.g. height, continuous data.
• Controlled by many genes (polygenes).
• Environmentla factors play major roles.
• …