One interaction between the nervous system and the skeletal system involves the calcium stored in the bones. The nervous system requires calcium for the proper transmission of nerve impulses. In which other way do the skeletal and nervous systems interact?

A. Red blood cells are produced in bone marrow.

B. The brain controls the contraction of muscles.

C. Bones protect the brain and spinal cord from injury.

D. The brain helps mount a defense against foreign bodies.

Interpret the model. a three-part model with black right-arrows between the parts. left part: a large green apple-shaped component with a w-shaped indentation centered on top. a small blue apple-slice shape sits above the left indentation and an arrow points from the shape to the indentation. a small purple apple-slice shape and arrow sit above the right indentation and an arrow points from the shape to the indentation. middle part: a large green apple-shaped component with a square indentation centered on top. sitting in the left side of the indentation is a blue apple-slice shape with a flat bottom, fused to a purple apple-slice shape with a flat bottom on the right side of the indentation. right part: a large green apple-shaped component with a w-shaped indentation centered on top. an up-arrow is centered above the indentation pointing to a fused blue and purple apple-slice-shaped flat-bottom component sitting above the indentation. assigne "true" or "false" to the end of each statement. the model shows a shape change occurring in the enzyme after the substrate is bound in the active site. t/fthere are two products in this model. t? f there are three substrates in this model. t/f the model shows two different enzymes. t/f

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.

Anormal strand of dna is shown below, followed by the same strand of dna after mutations have occurred.