If an isotope's half life is 2 months, and it starts with 240 grams. How many half life's does it take to only have 15 grams left? A. 2
B. 4
C. 6

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 ?

The image below shows a weather service map. which details best describe this map? check all that apply

Which is an example of a vestigial structure? a. tail of a monkey b. fin of a fish c. flower of a plant d. tailbone of a human