Dominant and Recessive Traits

What You'll Learn

Dominant alleles are expressed when present, while recessive alleles are only expressed when two copies are present. A person with one dominant and one recessive allele shows the dominant trait.

Key Words

recessive
life cycle

Steps

Step 1 — Read

Read and learn: Dominant alleles are expressed when present, while recessive alleles are only expressed when two copies are present. A person with one dominant and one recessive allele shows the dominant trait.

Step 2 — Do

Repeat the experiment two more times for accuracy.

Step 3 — Observe

Note any unexpected results.

Step 4 — Record

Share your findings with the class or a partner.

Check Your Understanding

Question 1

1 of 3

What is a dominant trait?