Question

Which of the following shows recessive traits?

• A. Inflated pod shape.
• B. Purple flower.
• C. Axile placentation.
• D. Length of stem.

Hint:

Recessive traits are expressed only when both alleles for that trait are recessive. In Mendelian genetics, dominant traits mask the expression of recessive traits.

Answer 1

The Correct Option is A

In genetics, traits are classified as either dominant or recessive. Dominant traits manifest if at least one dominant allele is present. Recessive traits, conversely, require the presence of two recessive alleles for expression. Considering these definitions, we will now identify the recessive trait from the given choices:

• Inflated pod shape: This is a recessive trait. For pea plants, pod shape can be either inflated or constricted. The inflated pod shape is expressed only when two recessive alleles are present.
• Purple flower: This is a dominant trait. Purple flower color is generally more prevalent as it is expressed with the presence of a single dominant allele.
• Axile placentation: This describes the arrangement of ovules within the ovary. In botanical contexts, this trait is not typically categorized by dominance or recessiveness in the same manner as pod shape or flower color.
• Length of stem: Stem length exhibits variability. However, without specific details regarding traits such as tall or short in established models like Mendel's pea plants, it cannot be definitively classified as a recessive trait in this context.

Conclusion: Among the listed options, "Inflated pod shape" is the trait that demonstrates recessiveness.