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 key genetics vocabulary.

Use the words below to complete the sentences.

1. A specific characteristic that an organism can pass to its offspring is called a  .

2. An organism that has two identical alleles for a trait is said to be  .

3. The genetic makeup of an organism, including both dominant and recessive alleles, is its  .

4. An allele that is always expressed when it is present is called a   allele.

5. The observable physical characteristics of an organism are its  .

6. An organism that has two different alleles for a trait is said to be  .

7. A   allele is only expressed when two copies are present, and the dominant allele is absent.

8. Different forms of a gene are called  .

1. If an organism has one dominant and one recessive allele for a trait, the recessive trait will be expressed.

2. Homozygous dominant individuals have two different alleles for a specific trait.

3. The phenotype is the observable physical expression of a genotype.

1. Which of the following describes an organism with two dominant alleles for a trait?

2. If 'B' represents the dominant allele for brown eyes and 'b' represents the recessive allele for blue eyes, what is the phenotype of an individual with the genotype 'Bb'?

1. Explain the difference between a dominant allele and a recessive allele. Provide an example for each.

2. How does an organism's genotype determine its phenotype?

Observe the image of a DNA double helix below.

3. Briefly describe the main components of the DNA structure shown in the image.