Cell Biology and Structure

Companion cell is specialized parenchyma cell, located in the phloem of flowering plants.

A cytoplasmic organelle specialized for carrying out oxidative reactions. It does not contain DNA.

A monocyte nucleus is kidney or bean-shaped.

The longest cells are neurons (nerve cells ) with a length of 90cm-100cm linking the central nervous system (brain and spinal cord) to other parts of the body. For example, for every receptor cell in your feet, there is a sensory neuron extending from the foot to the base of the spine..

The meristematic cells are comparitively small in size than matured plant cells.

Every permanent tissues contain either one or two large and distinct vacuoles. In a particular specialised cell, the vacuole is exhibited by lumen.

It is defined as the inner most layer of cortex having barrel-shaped parenchyma cells mainly meant for storing the food.

Callus is a mass of undifferentiated cells.

This includes cancer of bones, cartilages, tendons, adipose and tissues, etc.

Mitochondia is not found in bacterial cell. It is a characteristic feature of eukaryotic cell.

Molecules such as Bcl-2 and Bcl-XL prevent the release of pro-apoptotic proteins from mitochondria. Note, however, that some members of the Bcl-2 family, such as bid, have pro-apoptotic functions.

A cell can survive independently but not its organelles.

Cytoplasm is the jelly-like substance filling the cell, NOT an organelle. Organelles (mitochondria, ribosomes, Golgi bodies) are specialized structures suspended within the cytoplasm.

Neurogloea cells are absent in areolar tissues. 

These are cartilage-forming cells.