Which statement is true for cephalochordates?
a. notochord is present only in the larval stage; it is absent in adults.

b. notochord is present in the larval stage; it transforms to vertebrae in adults.

c. notochord is present throughout their lives.

1. the energy lost to disorder metabolism     -entropy

2. related to or possessing motion potential     -kinetic

3. all of the chemical reactions in an organism required for maintenance of the processes of life entropy     -metabolism

4. possible; ability to go into action or perform work kinetic     -potential

5. the study of energy and its transformations thermodynamics     -thermodynamics

the solute can move "downhill," from regions of higher to lower concentration, relying on the specificity of the protein carrier to pass through the membrane. this process is called passive transport or facilitated diffusion, and does not require energy.