Which structural characteristic is found in both plant and animal cells?
a. mitochondria
b. chloroplast
c. lysosome
d. cell wall

The best answer is A.

Mitochondria are small organelles found floating  free in the cytoplasm of both animal and plant cells. They consist of two membranes, an outer and inner membrane which has numerous folds creating layered structures called cristae.Inside the mitochondria, there is found  fluid called the matrix

 Mitochondria are the powerhouse of cells. Many of the reactions in cellular respiration that take place in the cell occur in mitochondria and thus these organelles are key in the production of energy .

when you breathe in, or inhale, your diaphragm contracts (tightens) and moves downward. this increases the space in your chest cavity, into which your lungs expand. the intercostal muscles between your ribs also enlarge the chest cavity. they contract to pull your rib cage both upward and outward when you inhale.

the answer is c. it will give up it's valence electron to the other atom.