Mitochondria is the powerhouse of a cell
Active transport requires energy when moving molecules against a concentration agent. It requires for specific membrane transport proteins. Only a certain type of protein can move a certain type of substance.
The three main types of Active Transport are:
1) Sodium-Potassium Pump
2) Endocytosis
<span>3) Exocytosis </span>
15. B.
16. G. schlerenchyma cells
17. D. ATP
The correct answer is (a.) Its spindle-shaped cells allow it to do smooth muscles. The structure of the cardiac muscles which is spindle-shaped is very important for the heart to withstand the stretching of the muscles during the contractions. Also for its smooth surface which is very important to prevent any possible blood clot during circulation.