If an organism has alleles BB, it means that it is homozygous dominant for that particular trait. Here's why:

* Alleles: Alleles are different versions of a gene. In this case, "B" represents one specific allele.

* Homozygous: Homozygous means having two identical alleles for a trait.

* Dominant: The "B" allele is dominant, meaning that it will be expressed even if only one copy is present.

What does this mean for the organism's phenotype?

The phenotype is the observable characteristic. Since the organism has two dominant alleles (BB), it will express the dominant trait associated with that gene. For example, if "B" represents brown eyes, the organism will have brown eyes.

Example:

Let's say eye color is determined by a single gene. If "B" represents the brown eye allele and "b" represents the blue eye allele:

* BB: Brown eyes (homozygous dominant)

* Bb: Brown eyes (heterozygous)

* bb: Blue eyes (homozygous recessive)