Andrew is describing the water cycle in three steps, as shown in this simple model. which statement belongs in the third region? a. water falls from the atmosphere as rain, ice, or snow. b. water turns to ice or snow and stays in the atmosphere. c. water in the clouds evaporates from the heat of the sun. d. water formed in the clouds causes the clouds to rise.

How does the molecular clock work? a. it analyzes the brain functionality of two different species. b. it examines and compares the physical characteristics of two different species. c. it illustrates relationships between two different species. d. it compares the number of mutations that exist in the dna of two different species.

Identify two examples of chemical reactions that you have encountered during the last week. identify an exothermic and endothermic reaction. explain.

Which of the following best describes the expensive tissue hypothesis? brains require more energy, so the gut had to be reduced, and larger brains and tool use led to higher quality diets. increasing body size means that homo neanderthalensis had to include more fat in its diet. brains require more energy, so the gut had to be reduced as brains got bigger. brains require more fat, so the gastrointestinal viscera (gut) had to expand, and hands were needed to acquire more food.