The current plight of the polar bear is an example of
-a generalist's ability to survive changing environmental conditions
-a case of overhunting endangered animals
-a specialized animal's inability to rapidly adapt to a changing environment
-a wild animal encroaching on human habitats

Liquid water turns into water vapor at which step in the water cycle

The phylogenetic tree illustrates the relationship between humans and our closest living relatives. the tree was based on biochemical comparisons, including dna and amino acid sequences. according to the biomolecular data, we could infer that a) the four organisms do not have a common ancestor. b) humans are more closely related to chimps than any other apes. c) chimps are more closely related to gorillas than they are to humans. eliminate d) there is no evidence if any relationship between the four branches on the tree.

Veins have a much lower blood pressure than arteries. which of these prevents backflow of blood in veins? a. pressure applied by the heart b. one–way valves in veins c. thin muscular walls of veins