Can someone help me with these questions?>.

Which statement best describes the relationship between an allele and a gene? question 1 options: an allele is a variation of a gene that can be expressed as a phenotype. an allele is the part of a gene that attaches to messenger rna molecules. an allele is a segment of a dna molecule that controls replication of a gene.

Why are scientists concerned about the depletion of the ozone levels in the stratosphere?

If jane has the blood type ab and marries john who has type o blood what are the possible phenotypes of their first kid?