What organs are affected by heart disease?

Acid rain is the direct result of acid released by burning fossil fuels. select the best answer from the choices provided ot o f true or false

Is snow a type of precipitation? explain why or why not.

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