Which of these is not a part of the circulatory system? heart blood arteries femur

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 ?

Hemoglobin is a proton that carries oxygen around the body what is hemoglobin made from

When fossil fuels are burned, carbon dioxide is released. how does this gas impact the environment?