1. nervous systems are required by animals to respond to stimuli and have complex senses such as taste, touch, sight, smell, or sound. these are carried by nerves to and from the brain and spinal cord. of all major animal phyla, which does not have nerves?

a. annelids
b. porifera
c. chordata
d. cnidarians

The majority of sulfur dioxide produced by industry comes from a. oil refineries. b. dry cleaners. c. chemical plants. d. coal-burning power plants.

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.

Do you think the gene eef1 alpha1 supports cell theory? explain your response.