If a radioactive substance's half-life is 20 years, how much of a 40-gram sample will be left after 60 years? a. 5 grams b. 10 grams c. 20 grams d. 30 grams

Imagine that a mouse has white fur because of a mutation in its dna. which of the following conclusions can be drawn

Monomers are the building blocks of larger molecules, called polymers. for example, proteins are composed of chains of amino acids that are linked together. cellulose is a polymer that makes up plant cell walls. cellulose is made from a chain of c6h10o5 molecules. which monomers are most likely used to produce cellulose? why?

Zoo geographic regions are characterized by the presence of specific groups of animals these regions are determined by the taxonomic or phylogenetic relationships of animals. the map shows the zoogeographic regions proposed by the naturalist alfred russel wallace in 1876. the similarities of organisms in which two areas numbered above provide the best evidence for common ancestry between the organisms in both locations ?