Which is NOT correct according to the best known model for a DNA molecule?
..A. Adenine pairs with thymine, cytosine with guanine.
B. It is composed of two strands made up of nucleotides.
C. The strands are held together by strong chemical bonds between the sugars.
D. The strands are twisted into a helix.

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.