The correct answers are:
Tissue level- similar cells work together to accomplish a goal.
Examples of tissue are muscles, skin, bone, and brain (nervous tissue).
A sponge is an example of an organism that is only organized to the cellular level.
Answer:
The answer is: Clonal selection produces memory cells that are long-lived and can recognize the antigen in the future.
Explanation:
The blood flows through the vessels of the heart to keep it going
There are more potassium ions inside the neuron than outside.
