Question

A trait is a characteristic shown by an organism. For example aTtplant would show the 'tallness' trait. In same way sickle cell anemia carriers should show a 'normal' trait, but I found on varioussitesthat SCA carrier have the sickle cell trait because they are a carrier and could pass it to their children. But it doesn't seem to make sense at all because showing a trait and passing it tot the next generation are different things. We do not sayTtplant have dwarfness trait just because it can pass it to the next generation. What does the term 'trait' really mean?

Answer 1

A trait is a physically expressed heritable characteristic, influenced by alleles. Dominant traits appear in the phenotype with just one dominant allele, while recessive traits, like sickle cell anemia, can be carried without physical expression but can be passed to offspring.

Step-by-step explanation:

A trait is defined as a variation in the physical appearance of a heritable characteristic. Traits are determined by alleles, which are the different forms of a gene. When Gregor Mendel conducted his experiments, he identified that there were dominant and recessive traits. Dominant traits are observed in the phenotype even if only one dominant allele is present alongside a recessive allele. For example, a plant with one allele for tallness (dominant) and one for dwarfness (recessive) will show the trait of tallness. However, carriers of a recessive trait, like sickle cell anemia, do not typically express the disease symptoms but can pass the allele to their offspring, where it can be expressed if paired with another recessive allele.

In population genetics, this phenomenon helps in the persistence of certain alleles within the gene pool. Therefore, when we talk about a 'sickle cell trait', it refers to the genetic potential to express or pass on the sickle cell characteristic, which should not be confused with the physical expression of the trait, as in the case of a plant showing tallness.