Which option shows all allele combinations that can be used to represent a purebred animal?
A) tt
B) TT or tt
C) TT or Tt
D) Tt
A) tt
The correct answer is:
B) TT or tt
Purebred animals are homozygous for a particular trait, meaning they have two identical alleles for that trait. In this case, the options TT or tt represent a purebred animal.
The option that shows all allele combinations that can be used to represent a purebred animal is:
A) tt
To understand why this is the correct option, let's first clarify some key concepts. In genetics, alleles are variations of a gene that determine specific traits in an organism. A dominant allele is represented by an uppercase letter (e.g., T), while a recessive allele is represented by a lowercase letter (e.g., t).
A purebred animal is an organism that has two copies of the same allele for a particular trait. In this case, the trait is represented by the letter "t". So, for an animal to be purebred for this trait, it must have two copies of the recessive allele "t".
Among the answer options provided, only option A) tt represents a combination of two recessive alleles for the trait. This means that both alleles of the animal are lowercase "t", fulfilling the criteria for a purebred animal.