Eukaryotic Cell : Characteristic in brief

-

Eukaryotic is a Greek word, made up by two words that is Eu means true and karyon means nucleus, that means which cell possess true nucleus , called Eukaryotic Cells. These cells are irregular, translucent masses of cytoplasm containing a nucleus. Structurally cell consists of mainly protoplasm which is made of two parts – 1. Cell wall  & 2. Cytosome.

read more : World Heritage Sites of India - Part 2

Characteristic of Eukaryotic Cells

1. Cell  Wall

  • Cell wall is absent in animal cells but present in plant cells which is hard, rigid non-elastic and quite porous.
  • This is the outermost bounding membrane.
  • It consists of an external thin primary wall and a thick inner secondary wall.
    • The primary walls of the two adjacent cells are often separated by the middle lamella.
    • The middle lamella is formed first by the secretion of cell.
    • The middle lamella is composed of viscous, gelatinous material, the pectin.
    • The primary wall is secreted against the middle lamella and is composed of cellulose fibers, pectin & other substances.
    • The secondary cell wall is secreted inside the primary wall which is composed of pectin, other noncellulose polysaccharides and lignin.
    • Lignin enriched the plant wood with its hardness and mechanical rigidity.
    • The cell wall provides supports and protection to the plasma membrane and cytoplasm.
  • In animal cells, the external covering is known as plasmalemma, cell membrane or plasma membrane.
    • It is living, ultra thin, elastic, porous and semipermeable.
    • It provides mechanical supportand external shape pf the protoplasm.
    • It controls the entry and exit of substances into the cell. The entrance of water and large molecules by the process of endocytosis and the exit of the products by exocytosis.
    • It is composed of lipid, protein and in some instances carbohydrates.
    • It consists of three layers – outer & inner layer are made of proteins and the middle layer is made of lipids.
    • In animal cells, the plasma membrane is covered and reinforced by the cell coat which is composed of glycoproteins, glycolipids and polysaccharides.
    • It also contains enzymes and antigens.

Eukaryotic Cell
2. Cytosome

Inner matrix of the cell is called as cytosome. It consists two parts – 
                i.    Cytoplasm &   
                ii.   Nucleus

i. Cytoplasm

  • Cytoplasm is amorphous, transluscent, homogeneous colloid fluid.
  • The peripheral layer of cytoplasm is called as ectoplasm also known as cortex. It is more rigid and devoid of granules.
  • The inner cytoplasm is called as endoplasm, is less viscous and contains different granules.
  • The ground cytoplasm is also known as ground matrix or hyloplasm, which behaves as a reversible sol-gel colloid system.
  • Hyloplasm bears many cell organelles such as ER, Golgi Complex, Lysosomes, Peroxysomes, Mitochondria, Ribosomes, Plastids, Metaplasm, centrosome, microtubules, celia & flagella and basal granules.
  • The cytoplasm consists of various inorganic compounds as water, salts of Na, K etc. and other metals.
  • It also consists various organic compounds like carbohydrates, lipids, proteins, nucleoproteins, nucleic acids and enzymes.

ii. Nucleus

  • Nucleus is present in the center of the cell, is rounded or ovoid body.
  • Nucleus is covered with extremely thin membrane which is called karyotheca or nuclear membrane which seperates nucleus from cytoplasm.
  • Nuclear membrane composed of two membrane – outer and inner, having nuclear pores. Both layers merges at the pores.
  • Inner nuclear membrane is in contact with the chromatin fibre, while outer nuclear membrane is continuous with the membrane of endoplasmic reticulum and plasma membrane.
  • These two nuclear membrane of the nucleus are separated by a space, known as perinuclear space.
  • Beneth the nuclear membrane nucleoplasm or karyolymph or nuclear sap is found, which fills the nuclear space.
  • The pores of the nuclear envelope are filled with electron dense proteinaceous substance called the annular material.
  • Chromatin, nucleolus, endosomes etc. are embedded in the matrix of nucleus or nucleoplasm.
  • Nucleus controls the all vital activities of the cytoplasm and carries the hereditary materials DNA.
  • Nucleoplasm or nuclear sap contains dissolved phosphate, ribose sugers, proteins, nucleotides and nucleic acids. It also possess chromosomes which is formed of ultra thin threads like structures called chromatin.
  • In the nucleoplasm also occurs a spherical conspicuous body called nucleolus or nucleoli. It is composed of ribosomal RNA and Ribosomal proteins.
  • The nucleoli is either single or multiple and usually acidophilic in nature.
Location: V469+46 Bigga NSW, Australia

Comments

Post a Comment

Popular posts from this blog

Indian Martial Art - Part 4

-
Image
Indian Martial Art The  literal meaning of 'martial art' is - 'art related to waging war'.  As we all know,  India is a country of traditions and cultures . Indian martial arts or martial arts are also one of the many variations of India. In ancient times, these martial arts played an important role in defeating the opposing side and establishing their supremacy over the dynasties and primitive tribes, but in the present context, if we look at these martial arts, they are  used generally in Physical health benefits, for self-defense, for religious rites and in the film world. These martial arts are mainly related to dance, yoga and performance arts. Different Branches and Sub-Branches of Science and Their Fields of Study Different Types of Indian Martial Arts Different types of martial arts are prevalent in different states and regions of India, some of which we will see in this article. We will see the details of the remaining others in the next article under differ...
Read more

Evolution of the Indian Constitution : Historical Background (Part - 2)

-
Image
Evolution of the Indian Constitution : Historical Background (Part - 2) We will understand the material related to the development of the Indian Constitution in the following four parts, whose links are as follows – Evolution of the Indian Constitution : Historical Background (Part - 1) Evolution of the Indian Constitution : Historical Background (Part - 2) Evolution of the Indian Constitution : Historical Background (Part - 3) Evolution of the Indian Constitution : Historical Background (Part - 4) We can divide the development of the Indian Constitution mainly into two categories – Acts passed under the British East India Company (1773 – 1853) Regulating Act 1773 Act of Settlement 1781 Act of 1786 Pitt's India Act 1784 Charter Act, 1793 Charter Act, 1813 Charter Act, 1833 Charter Act, 1853 Acts passed under the British Crown (1857 – 1947 ) Government of India Act, 1858 Indian Councils Act, 1861 Act of 1873  Imperial Titles Act, 1876 Indian Councils Act, 1892 Indian Councils Act, 1...
Read more

Major Facts Related to Lakes of India And The World

-
Image
Major Facts Related to Lakes The major facts related to lakes are as follows , which can be categeorise into Lakes of the World and The lakes of the India. These are as follows -  Albinism : Genetic Mendelian Abnormality Lakes of the World Deepest lake – Lake Baikal (1750 m.) The lowest depth lake – Lake Chad of Africa (3 m.). Largest lake – Caspian Sea, followed by Lake Tanganyika. Longest lake – Lake Tanganyika (660 km), Fresh water lake. Largest fresh water lake – Lake Superior (US) | Highest navigable lake – Titicaca (located on the border of Peru and Bolivia) Highest lake – Tisso Sikru (located in the plateau of Tibet). Largest caldera lake – Tobajil (Indonesia) | Most salinity lakes – Turkey's Van Lake (330%), Jordan's Dead Sea (238%), America's Great Salt Lake (220%). Edicts and Architecture of Mauryan Lakes of India The lakes located in the deltaic regions of the river Ganges are called Bhils. The lagoon lake located on the west coast of India is called Kayal. Bemba...
Read more