Benefits of regular exercise outweigh the risk of injury. a. true b. false

What is thought to have caused the mass extinction at the end of the cretaceous period?

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.

Select the correct answer from each drop-down menu proteins are