Ace the Australian Year 10 Biology Test 2026 – Unleash Your Inner Science Dynamo!

The term that refers to the observable characteristics of an organism is phenotype. This encompasses all the traits that can be physically seen or measured, such as height, eye color, and leaf shape in plants. The phenotype results from the interaction between an organism's genetic makeup (genotype) and its environment.

In contrast, genotype describes the specific genetic makeup of an organism, including all the alleles present, whether they are expressed or not. Alleles are variants of a gene that can influence the phenotype but are not observable traits themselves. Chromosomes are structures that organize and carry genetic information but do not directly refer to the characteristics of an organism. Understanding this distinction helps clarify how traits are expressed and the role of genetics in development.