Question

What is the difference between dominance and recessiveness? .

Hint:

In genetics, dominant traits are always expressed when present, while recessive traits need two copies to be visible.

Answer 1

Step 1: Understanding Dominance and Recessiveness.
Dominance is a genetic phenomenon where the dominant allele expresses its trait in a heterozygous pair, while the recessive allele only expresses its trait when two recessive alleles are present.
Step 2: Explanation.
For example, in pea plants, the allele for tall plants (T) is dominant, and the allele for short plants (t) is recessive. A plant with genotype Tt (heterozygous) will be tall because the dominant T allele masks the effect of the recessive t allele.
Step 3: Conclusion.
Thus, the correct answer is ((A).
Final Answer: \[ \boxed{\text{Dominance refers to the allele that expresses its effect even in the presence of a different allele; recessiveness requires two copies to express its trait.}} \]