Question

What is the “jelly-like” substance that fills the cell?

Answer 1

Hint: Cells are the fundamental unit that is membrane-bound. This “jelly-like” substance is the important constituent of the cell that makes the cell living and helps in holding the various cell organelles together. It is made up of some major organic molecules such as carbohydrates, proteins, nucleic acids, and lipids.

Complete answer
The cytoplasm of the cell contains the cell organelles and is called a “jelly-like” substance. The thick gel-like substance found inside the cells is called the cytoplasm that is found to be covered and protected from the outer environment by the cell membrane. The cytoplasm is made up of cytosol, a gel-like substance, and inside it are embedded the various cell organelles that include the mitochondria, endoplasmic reticulum, lysosome, vacuole, Golgi body, chloroplast (in plant cell), etc and all these are enclosed inside a cell membrane. It includes several cytoplasmic inclusions and is about $80\%$ of the water and is usually colorless. There are various cellular and metabolic processes that occur inside the cytoplasm that includes the process of cell division, glycolysis, etc. Endoplasm is the inner layer of the cell and the outer layer is the cell cortex or the ectoplasm of the cytoplasm. The movement of the calcium ions inside and outside of the cell cytoplasm will act as the signal for various metabolic processes resulting in the movement of the cell cytoplasm around the vacuoles in the case of the plants, this process is known as the cytoplasmic streaming.

Note:
The prokaryotes are the primitive organisms thus there is no differentiation in between their cytoplasm and other cell organelles found in the cell. They do not have a proper nucleus thus the cytoplasm itself contains the chromatin material and carries the genetic material of the organism. Their cytoplasm will act at the nucleoplasm of the eukaryotic cells. While the eukaryotes are the advanced organisms and consist of both the nucleus and the cytoplasm, so the cytoplasm will cover only the outer area of the cell while the inner area of the cell is occupied by the nucleus.