A particular single-celled organism uses radiant energy to fix carbon as sugars. This organism generates ATP by breaking down sugars through a process that uses oxygen. Based on this information, how should this organism be classified? A. aerobic heterotroph
B. aerobic autotroph
C. anaerobic autotroph
D. anaerobic heterotroph

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.