an organism's genotype is
an observable trait
a trait that is expressed in a homozygous individual
the set of alleles an organism's has for a trait
an allele that is expressed whenever it is present
The correct answer is: the set of alleles an organism has for a trait.
The correct option is: the set of alleles an organism has for a trait.
An organism's genotype refers to the specific combination of alleles it possesses for a particular trait. It encompasses both the dominant and recessive alleles that an organism carries for that trait. Genotype determines the potential traits that an organism can exhibit, although the physical expression of these traits is influenced by other factors such as the environment.
The correct answer is: the set of alleles an organism has for a trait.
To understand why, let's break down the other options:
- "An observable trait" refers to the phenotype, which is the physical or observable expression of the genotype. This is not what the genotype itself is.
- "A trait that is expressed in a homozygous individual" refers to a homozygous phenotype, where the individual has two identical alleles for a particular trait. This is also description of the phenotype, not the genotype.
- "An allele that is expressed whenever it is present" is an incorrect definition. All alleles can potentially be expressed, but whether or not they are expressed depends on various factors, such as dominance relationships and gene interactions.
Therefore, the genotype is best defined as the set of alleles an organism has for a particular trait. It represents the genetic makeup of an individual, including both the dominant and recessive alleles present. Knowing an organism's genotype is crucial for understanding inherited traits and genetic variation.