Genetics Vocabulary: Dominant and Recessive

Genetics Vocabulary: Dominant and Recessive

Read each question carefully and answer to the best of your ability. This worksheet will test your understanding of dominant and recessive traits, as well as other key genetics vocabulary.

Use the words below to complete the sentences.

1. A   is a unit of heredity that is transferred from a parent to offspring.

2. An   is one of two or more alternative forms of a gene that arise by mutation and are found at the same place on a chromosome.

3. A   trait is one that will always be expressed if the allele is present.

4. A   trait is only expressed when two copies of the allele are present.

5. The genetic makeup of an organism, represented by letters, is its  .

6. The observable physical characteristics of an organism, such as eye color or height, is its  .

7. Which of the following represents a homozygous dominant genotype?

8. If an individual has one dominant allele and one recessive allele for a trait, what will their phenotype be?

9. A recessive allele will always be expressed if it is present in the genotype.

10. The phenotype describes the physical appearance of an organism.

11. Explain the difference between a dominant allele and a recessive allele. You may use a diagram to help your explanation.

12. Describe what a 'heterozygous' genotype means.