What force is stopping the movement of a photon at a sunspot

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.

Which of the following cell structures is significantly different between gram- positive and gram-negative bacteria?

What does the number 18.9984 represent in the image?