TNPSC Free Notes Biology -Cell Theory

இந்தக் கட்டுரையில், TNPSC குரூப் 1, குரூப் 2, குரூப் 2A, குரூப் 4 மாநிலப் போட்டித் தேர்வுகளான TNUSRB, TRB, TET, TNEB போன்றவற்றுக்கான  முறைகள் இலவசக் குறிப்புகளைப் பெறுவீர்கள்.தேர்வுக்கு தயாராவோர் இங்குள்ள பாடக்குறிப்புகளை படித்து பயன்பெற வாழ்த்துகிறோம்.

Cell Theory:

In 1833, German botanist Matthias Schleiden and German zoologist
Theodor Schwann proposed that all plants and animals are composed of cells
and that cells were the basic building blocks of life

Types of cells:
On the basis of the cellular organization and the nuclear characteristics, the
cell can be divided into
1. Prokaryotes
2. Mesokaryotes and

3. Eukaryotes

Prokaryotes:
Those organisms with primitive nucleus are called as prokaryotes (pro –
primitive; karyon – nucleus). The DNA lies in the
‘nucleoid’ which is not bound by the nuclear membrane and therefore it is not
a true nucleus

Mesokaryotes:
 In the year 1966, scientist Dodge and his coworkers proposed another
kind of organisms called mesokaryotes. These organisms which shares
some of the characters of both prokaryotes and eukaryotes.
 Example: Protozoa of Noctulia

Eukaryotes:
 Those organisms which have true nucleus are called Eukaryotes (Eu –
True; karyon – nucleus).
 The DNA is associated with protein bound histones forming the
chromosomes.
Difference between plant cell and animal cell:

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