Aprotein channel is a transport protein that a. always moves substances against a concentration gradient. b. pumps ions out of a cell. c. serves as a tunnel for specific substances. d. always requires energy from the cell.

Which of the following is not a classification of marine organisms? a. benthos c. neritic b. nekton d. plankton select the best answer from the choices provided a b c d

Imagine that certain laws of physics could be ignored and you were able to travel vast distances in moments. now imagine that you traveled to an earth-like planet located light-years away that is known to support life. think about what you’ve learned in this unit and make an argument for what you think would be the dominant type of life form on this planet. consider whether a notochord is required for an organism to manipulate its environment and become a dominant creature.

According to cell theory; which structures carry out the basic function of living things? a. atoms b. organs c. cells b. nuclei