Mitochondria is the 'factory' or the 'powerhouse' of the cell! I've just been learning about them too!
Answer:
d . different population of the same species physically separated from each other forming new species.
A chemical change has occurred because the wood has turned into a substance that can't be changed back to it's original form. The wood has turned to ash, chemical changes are non reversible.
Answer:
Parietal cells in the gastric glands in the stomach.
Explanation:
The main constituent of gastric acid is hydrochloric acid produced and that is roduced by parietal cells in the gastric glands in the stomach.