The physical appearance of an organism is described as its

1. Analyze the question The question asks for the term used for the physical appearance of an organism, meaning the traits you can see or measure, such as height, skin colour, or flower colour.

2. Explain the concept

• Phenotype: the observable characteristics of an organism. It results from the genotype interacting with the environment.
• Genotype: the genetic makeup of an organism, meaning the combination of alleles it carries (e.g., TT, Tt, tt). You cannot see it just by looking.
• Allele: one of the alternative forms of a gene (e.g., T for tall, t for dwarf).
• Chromosome: a thread-like structure in the nucleus that carries genes.

3. Work through the options

• A. Phenotype: describes physical appearance. ✔
• B. Genotype: describes genetic composition, not appearance. ✘
• C. Allele: a form of a gene, not an appearance. ✘
• D. Chromosome: a structure carrying genes. ✘

4. Answer The physical appearance of an organism is its phenotype.

5. Tip Link the words: Phenotype = Physical appearance. Genotype = Genes. Also remember the formula: Genotype + Environment → Phenotype.