The heart is made up of the left and right and the left and right . atria, ventricles

t-sacs, v-tubes

lungs, kidneys

none of the above

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.

Several billion years ago which gas was the least prevailant in the atmosphere

Each nephron is made up of capillaries that form the __ sweat glands bladder glomerulus ureter