Question

in the abo series of human blood types, people have only one kind of blood type, either a, b, ab, or o. this illustrates what kind of variation?
○ continuous
○ contingent
○ discontinuous
○ genetic

Explanation:

1. First, recall the definitions of each term:

• Continuous variation: Shows a range of values (e.g., height, weight), with no distinct categories.
• Contingent: Relates to dependence on conditions, not a type of biological variation here.
• Discontinuous variation: Involves distinct, non - overlapping categories (e.g., blood types: A, B, AB, O are distinct and you can only be one of them).
• Genetic: While blood type is genetic, the question is about the type of variation (discontinuous vs continuous), and blood type's distinct categories fit discontinuous. But wait, the original selected option was wrong. Wait, no, let's re - evaluate. Wait, the options: the correct type of variation for blood types (A, B, AB, O, each person has one) is discontinuous because there are distinct, separate categories with no intermediate forms. But the original selected "Genetic" is about the cause, not the type of variation. Wait, no, maybe I misread. Wait, the question is "what kind of variation". Discontinuous variation is when traits fall into distinct categories (like blood types: you are either A, B, AB, or O, no in - between). Continuous is like height where there's a spectrum. Contingent is not a standard biological variation term here. Genetic is the cause, not the type of variation. So the correct answer should be Discontinuous. But let's check again. The options are Continuous, Contingent, Discontinuous, Genetic. The key is that blood types are distinct categories, so discontinuous variation. So the correct option is Discontinuous.

Answer:

C. Discontinuous