PLEASE HELP! 20PTS!!

Air pollution is only caused by human activity, select the best answer from the choices provided ot of true or false

What came first egg or chicken? and is tomato a vegetable or a fruit?

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.