Skip to main content

An overview of cell

  •  A typical plant cell, has a distinct cell wall as its outer boundary and just within it is the cell membrane .
  • Cells that have membrane bound nuclei are called eukaryotic whereas cells that lack a membrane bound nucleus are prokaryotic .
  • in both prokaryotic and eukaryotic cells,  a semi- fluid matrix called cytoplasm occupies the volume of the cell.
  • The cytoplasm is the main arena of cellular activities in both the plant and animal cells. various chemical reactions occurs in it to keep the cell in the living state.,
  • Besides the nucleus, the eukaryotic cells have other membrane bound distinct structures called organelles like the endoplasmic reticulum (ER), the golgi complex, lysosomes, microbodies . the prokaryotic cells lack such membrane bound organelles.
  • Ribosomes are non-membrane bound organelles found in all cells - both eukaryotic as well as prokaryotic cells. Within the cell, ribosomes  are found not only in the cytoplasm but also within the two organelles chloroplast (in plants ) and mitocondria and on rough ER .

Animal cells contain another non-membrane bound organelle called centriole which helps in cells division.

SIZE :-

  • Cells differ greatly in size , shape and activities .
  •  Mycoplasma (smallest cells) ; only 0.3µm in length [PPLO (pleuro pneumonia like organism) ] is a type of mycoplasma having the size about 0.1µm .
  • Largest isolated single cell = egg of an ostrich .
  • Human red blood cell = 7.0µm in diameter .
  • Nerve cell = longest cell
Shape:-
       

Comments

Post a Comment

Popular posts from this blog

Digestion and Absorbtion

Digestion is the complex process by which your body breaks down the food you eat into nutrients that can be absorbed and used for energy, growth, and repair. It begins in the mouth and continues in the stomach, small intestine, and large intestine. Here's a simplified overview of the digestive process: Ingestion: The process starts when you eat food. Chewing in the mouth breaks down the food into smaller particles and mixes it with saliva. Mechanical and Chemical Digestion in the Mouth: Saliva contains enzymes like amylase that begin breaking down carbohydrates in the food. Chewing also helps break down the food mechanically. Swallowing: The tongue pushes the partially digested food (called bolus) to the back of the throat, and then it's swallowed, moving it into the esophagus. Esophagus: The esophagus is a muscular tube that carries the bolus of food from the mouth to the stomach through a coordinated process called peristalsis. Stomach: The stomach is a J-shaped organ that co...
Post a Comment
Read more

What is cell

  NCERT  ask this question to you and give some difficult answer of it . let us simplify :-                             A cell is the structural and functional unit of life.                          A cell is defined as the smallest basic unit of life that is responsible for all of the life`s processes.
Post a Comment
Read more