Cell growth is the process by which cells accumulate mass and increase in physical size. In some cells, size is proportional to DNA content. For instance, continued DNA replication in the absence of cell division (called endoreplication) results in increased cell size.

Cells are limited in size because the outside (the cell membrane) must transport the food and oxygen to the parts inside. As a cell gets bigger, the outside is unable to keep up with the inside, because the inside grows a faster rate than the outside.

Body tissues grow by increasing the number of cells that make them up. But some cells, such as skin cells or blood cells are dividing all the time. When cells become damaged or die the body makes new cells to replace them. This process is called cell division.

For most cells, this passage of all materials in and out of the cell must occur through the plasma membrane (see diagram above). Each internal region of the cell has to be served by part of the cell surface. As a cell grows bigger, its internal volume enlarges and the cell membrane expands.

The size of the cells of an organism has no relation with the sizeof its body. Cell – Structure and Functions.

Animal cells have centrosomes (or a pair of centrioles), and lysosomes, whereas plant cells do not.

Answer. chloroplasts are not present in animal cell as they are in plant cells for doing photosynthesis. cell wall are also not present in animal cell.

The nucleus is considered to be one of the most important structures of eukaryotic cells as it serves the function of information storage, retrieval and duplication of genetic information. Thus, nucleus provides functional compartmentalisation inside the cell allowing higher levels of gene regulation.

Ribosomes are found ‘free’ in the cytoplasm or bound to the endoplasmic reticulum (ER) to form rough ER. In a mammalian cell there can be as many as 10 million ribosomes. Several ribosomes can be attached to the same mRNA strand, this structure is called a polysome.

nucleus