CYTOLOGY PART-2

Difference between DNA and RNA

DNA RNA
  • Deoxyribose sugar is found in DNA.
  • In DNA base Adenine, Guanine, thiamine, and cytosine are found.
  • Almost all DNA is to be found in the Nucleons of the cell.
  • Ribase sugar is found in RNA.
  • In RNA on the behalf of thiamine base of uracil comes into existence.
  • TNA is mainly to found in Cytoplasm.

Cytoplasm: – This is the part of the cell other than nucleons which have various components like endoplasmic reticulum, Golgi apparatus, lysosome, mitochondria, ribosome, centrosome, plastid, leucoplast chromoplast, vacuoles etc.

Endoplasmic reticulum: –  E R was firstly invented by porter in 1945 and it is spread between cell membrane and nuclear membrane in the cytoplasm which is of two types

  • Smooth walled ER: – at it, no ribosome is to be found and it is the respondent for the lipid secretion.
  • Rough walled ER: – at it, the ribosome is to be found which helps in protein synthesis.

Golgi apparatus or  Golgi body: –  it was invented by Camille Golgi and it is basically composed of a group of tubules and vesicles thus Golgi apparatus is called a traffic control of the cellular molecules. Golgi apparatus also forms the cell wall and lysosomes.

Lysosomes: –  It was invented by De-Duve. It is composed of the membrane in the form of a packet which is found abundantly in every cell. This lysosome helps in cellular digestive activities and that is why it is also called digestive vesicle and whose main functions are,

  • Lysosome destroys every foreign substance like bacteria etc. inside the cell.
  • Lysosome replaces old and weak cellular organelles, so that new cellular organelles originate inside the cell.
  • It is also called suicide vesicle(bag) of the cell.

Mitochondria: – it was invented by Altman and Benda. Altman called it bioplast and Bandra called it Mitochondria. It was firstly seen by fleming in 1882. Through this electrons are transferred andy “adenosine triphosphate”(ATP is formed it is also called the powerhouse of the cell.

Ribosome: – It was invented by G.E. Palade in 1955 by the help of an electron microscope. Nearly 80% of r-RNA is formed by ribosome and diameter of it varies from 150 A0-250A0. It is also called the factory of protein. Until all invented cell organelles ribosome is the smallest among all and I was firstly seen by cale de in 1941 and called microsome, later in 1955 it was called ribosome by the palate.

Centrosome: – It was first invented by T.Boveri in 1888. This cell organelle is only found in animal cells and it composed two scenarios which are mutually confined along the transverse axes. Sometimes centrosome is called as diplosome. It also helps in cell division and it forms spindle fiber.

Plastid: – Found in plant cells and its shape is like mitochondria.

It was divided into two categories.

Lencoplast: – Found in the cell of these parts of the parts of the plant which are derived from sunlight like roots, underground stem etc.

Chromoplast: – This is a colored plastid which has usually red, yellow or orange color found in colored parts of the plant like flowers, the interior of fruits, seeds etc.

Chloroplast: – These are green colored substance called chlorophsp used for photosynthesis, provides starch for leafs

Types of cell: –  It is of two types

  • Prokaryotic cell: – In this type of cell all around the nucleus there is a lack of nuclear membrane in prokaryotic cells many organelles like chloroplast, lysosome, Golgi body, Mitochondria etc are absent such prokaryotic cells are found frequently in the virus, bacteria, blue-green algae.
  • Eukaryotic cell: – In this type of cell all around the nucleons a completely developed nuclear membrane is found and all the cell organelles like chloroplast, lysosome, Golgi body, mitochondria etc are present in eukaryotic cells cell wall is completely developed and which is composed of cellulose.
Prokaryotic cell Eukaryotic cell
  • Size about from 1-10 micron.
  • A nucleus is not surrounded by the nuclear membrane.
  • In it only one chromosome is found.
  • Cell organelles, nucleolus are absent.
  • Size about 5-100 micron.
  • Nucleons are surrounded by the nuclear membrane.
  • In it, more than one chromosomes are found.
  • Cell organelles, nucleolus are present

 

 

Difference between plant cell and animal cell

Plant cell Animal cell
  • In plant cell tri-layered cell wall is found which is made from cellulose.
  • In almost all plans cell except some like Fungi, Bacteria etc chlorophyll is found.
  • Centrosome doesn’t occur in a plant cell.
  • Lysosome usually doesn’t occur in the plant cell.
  • The vacuole is to be found in almost all plant cell.
  • In almost all plant cells centrioles do not exist.
  • There is on a cell wall in the animal cell but the cell is covered by a Plasma membrane.
  • No chlorophyll is found in the animal cell.
  • In animal cell near the nucleus, the centrosome is to be found which takes part in the cell division.
  • Lysosome occurs in the animal cell.
  • The vacuole is not to be found in the animal cell.
  • In almost all animal cells centrioles exist.

 

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