4. the maximum size of a cell is determined
by the ratio between the cell's
a. surface area and volume.
b. volume and organelles.
c. organelles and cytoplasm. ·
d. cytoplasm and nucleus.

The maximum size of cell is explained by the ratio between the cell's surface area and its volume.

Explanation:

Cells are surrounded by lipid bilayer known as plasma membrane which gives them unique shape and inside they are filled with cytoplasm in which many organelles are present including nucleus and other organic molecules. The size of the cell can be estimated by the ratio of its surface area to volume. Here, the surface area is the uppermost layer which is the the lipid bilayer of the cell. Suppose if the cell is spherical in shape then its surface area will be  and the volume of the sphere will be

After putting the values we will know that if the surface area is bigger than the volume of cell then the size of the cell will be smaller and if the surface area of a cell is smaller the volume of the same then the cell will be bigger. Here, the volume represents the amount of space present inside the cell and the surface area of cell represents the total covering of the cell.

i believe it is "they are not used up by reactions" as the answer to your question, text me back if this is correct because i just learned this.

several tissues working together form an organ, and several organs together make up an organisms.

the group of cell that carries out special jobs are tissue.