Which statement is accurate about dominant alleles?(1 point)
Dominant alleles are always expressed over recessive alleles in a heterozygous individual.
To determine which statement is accurate about dominant alleles, we first need to understand what dominant alleles are.
Dominant alleles are versions of a gene that will always be expressed in an individual's phenotype, even if only one copy of the allele is present. In other words, if an individual has a dominant allele for a certain trait, that trait will be displayed in their physical appearance or other observable characteristics.
Now, let's consider the possible statements about dominant alleles:
1. Dominant alleles are always more common in a population than recessive alleles.
2. Dominant alleles always determine the physical appearance of an individual.
3. Dominant alleles always require two copies to be present for a trait to be expressed.
4. Dominant alleles mask the effects of recessive alleles when present together.
To determine which statement is accurate, we need to evaluate each statement.
Statement 1: This statement is not necessarily true. The frequency of dominant alleles in a population depends on various factors such as the nature of the trait, selection pressures, and genetic variation. Dominant alleles can be either common or rare.
Statement 2: This statement is not accurate. Dominant alleles may determine the physical appearance of an individual for some traits, but not for all traits. Some traits are influenced by multiple genes or have interactions between different alleles.
Statement 3: This statement is not true. Dominant alleles only require one copy to be present for a trait to be expressed. In contrast, recessive alleles require two copies (one from each parent) to be expressed.
Statement 4: This statement is accurate. Dominant alleles can mask the expression of recessive alleles when both are present in an individual. This is known as dominance and is a fundamental principle in genetics.
Therefore, the accurate statement about dominant alleles is that dominant alleles mask the effects of recessive alleles when present together.