After 3 half lives how much of a radioactive substance will remain
1/16
1/4
1/2
1/8

Select all the true statements about the cosmic microwave background radiation

What two fields of study provide the core information that is used to classify organisms?

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.