What is variation?
What does variation mean in biology?
Differences between individuals of the same species.
Is a person's ABO blood group inherited from their parents?
Yes. ABO blood group is determined by genes inherited from parents.
Is human height continuous or discontinuous variation?
Continuous variation.
What characteristic did we measure today?
Hand span on the right hand.
Give ONE example of variation between humans.
For example: height, hand span, natural hair colour or ABO blood group.
What environmental factor causes a suntan?
Sunlight / ultraviolet (UV) radiation.
ABO blood groups are A, B, AB and O. Is this continuous or discontinuous variation?
Discontinuous variation. There are separate categories.
What type of graph did we draw to show our grouped hand-span measurements?
A histogram.
A cat and a dog look different. Does this show variation WITHIN a species? Explain.
No. A cat and a dog are different species. Variation within a species means differences between individuals of the same species.
Height is affected by genes AND the environment. Name ONE environmental factor that can affect growth.
Nutrition / diet, or illness during childhood. Accept another valid environmental factor affecting growth.
Why is hand span an example of continuous variation?
Intermediate values are possible. For example, a hand span can be 17 cm, 17.5 cm or 18 cm.
Look at our class histogram. Which hand-span interval has the most students?
Use the actual class histogram: accept an interval with the highest frequency. If intervals tie, accept any interval with the highest frequency.