Which of the following best describes a wild type in genetics?

• A. An organism that has a mutation causing a rare phenotype
• B. An organism that is genetically engineered in the laboratory
• C. An organism that is homozygous for a recessive allele
• D. An organism that possesses the most common phenotype or genotype found in natural populations

Answer: (D)

Verified step by step guidance

1. Understand the term 'wild type' in genetics: it refers to the phenotype or genotype that is most commonly found in natural populations of a species.
2. Recognize that a wild type is considered the 'standard' or 'normal' form against which mutations or variations are compared.
3. Identify that organisms with mutations causing rare phenotypes are not wild type because they differ from the common form.
4. Note that genetically engineered organisms are artificially modified and thus do not represent the natural wild type.
5. Understand that being homozygous for a recessive allele may produce a rare phenotype, so this does not define the wild type either.