Which characterization accurately describes both conduction and convection

Both conduction and convection need matter to transfer thermal energy.

Both only occur when currents are created by different densities.

Conduction involves collision of particles, while convection involves the movement of a liquid or gas.

or both only occur when currents are created by different densities.  

(I tried my best to find the answer, let me know if this was helpful, goodluck!)

it's the cell cycle, but cytokines is when the cell divides.

theres 3 stages interphase,mitosis,and cytokines.

interphase prepares the cell for division.

mitosis is the process of dividing the cell,it has 4 parts interphase,anaphase,metaphase,and telophase.

lastly there's cytokines,that's when the cell divides into 2 daughter cells

lizards have adapted to life in the desert. some desert lizards have toes with spiny scales to them run across the sand without sinking. some use the sand to hide from predators, or to search for small animals that they prey upon.