Aquatic mammals, such as seals and dolphins, are able to stay submerged in water for long periods of time because of the mammalian diving reflex. when submerged in cold water, and while the mammal is holding its breath, receptors in the nasal cavity and other areas of the face relay a message to the brain that causes blood to only circulate between the heart and the brain. this allows oxygen to be conserved and increases the time aquatic mammals can stay underwater between breaths. the mammalian diving reflex is an example of what process?

Match each description to the appropriate biome. tropical savanna desert tropical rain forest taiga tundra has sparse vegetation and very cold temperatures located near the equator and contains trees that form dense canopy layers is very hot and dry, and has plants that need little water has cold winters, heavy snowfall and is dominated by conifers has warm temperatures and is dominated by grasses

Cladistics is a way of classifying organisms by examining the characteristics of their ancestors and descendants and depicting the relationships in a cladogram. which of the following best describes a challenge in classifying organisms this way? a. there are millions of species on earth, and a cladogram is not a practical means for classifying all of them. b. it is impossible to tell which organisms are most closely related to each other using a cladogram. c. cladograms are detail-oriented and do not provide a useful understanding of evolutionary relationships. d. there is a limited number of ways to organize the information, so most cladograms end up looking very similar.

An animal cell (left) and a plant cell (right) are shown. which organelle, labeled x in the diagram, is found in both plant and animal cells?