Question

Write a short note: cytoplasm & nucleus?

Answer 1

A typical cell is composed of three elements: cell membrane , cytoplasm and nuclear material. There are two types of cells: prokaryotic and eukaryotic. This classification is based on three main features (i) organization of biomembranes (ii) variety of cytoplasmic organelles and (iii) complexity of nuclear material.

Complete step by step answer:
CYTOPLASM:-
-It is a watery solution containing controlled concentrations of inorganic and organic compounds.
-It functions as the seat of metabolism to provide energy and materials for growth and reproduction.
-Cell organelles such as mitochondria, ribosomes, golgi apparatus etc are suspended in the cytoplasm
-Most of the important activities occur in the cytoplasm.
-Without cytoplasm the cell would be deflated and material would not pass easily from one organelle to another.
-The cytoplasm is the main arena of the activities in the plant and animal cell.

NUCLEUS:
Nucleus is the master of the cell.
It is generally located in the center of the cell.
Nucleus as cell organelle is first described by Robert Brown in 1831.
Perinuclear space forms a barrier between cytoplasm and nucleus.
Nucleus consists essentially of DNA.
It serves to store and transmit the information to direct the synthetic activities of the entire cell.
The mechanism of storing, transmitting and utilizing the genetic information are similar in both the eukaryotic and prokaryotic cell.

Additional information:
Prokaryotic cell - It is a single membrane system. Cell wall surrounds the plasma membrane in most cases. It is composed of peptidoglycans comprising polysaccharides linked to amino acids. Strengthening material is murein. Cell membranes bear respiratory enzymes.
Eukaryotic cell : It is a double membrane system. Cell wall surrounds the plasma membrane in some protists, most fungi and all plants. It is composed of polysaccharides. Many strengthening materials are chitin in most fungi and cellulose in others. Animal cells lack cell walls.

Note:
The prokaryotic cells are morphologically the most primitive cells. The eukaryotic cells have a more elaborate internal organisation than prokaryotic cells.