Ahuman head hair is best characterized by: a. the absence of a cortex. b. its scale pattern. c. a medulla that is more than 1/2 the overall diameter of the hair shaft. d. a medulla that is absent or is less than 1/3 the overall diameter of the hair shaft.

After reading the paragraph below, answer the questions that follow. researchers have created a robot that has a very thin leg that is moved by cardiac (heart) cells contracting in unison. the robot, made of a polymer similar to that used in making contact lenses, is bathed in heart cells with supporting cells, which then attach to the robot and provide movement as they contract. all of the cardiac cells working together can cause the robot leg to move in a way that individual cells could not. this is an example of a. emergent properties of cells. b. energy flow through an ecosystem. c. adaptation. d. internal environment regulation.

Amylase is an enzyme found in the human digestive system. why do you think it was important to keep the enzyme temperature above 37 degrees celsius (98.6 degrees f)? describe what might happen if the temperature decreased by 10 degrees celsius.

Johnny rode his bike to a friend's house 4 blocks down the street in his neighborhood. he immediately rode back home once he realized his friend was not able to play. what was his displacement for the total bike ride? how did you determine this? what could we use as a reference point to determine he was in motion during his bike ride? why can you use it as a reference point