Cells – Class 11 | Chapter – 8 | Short Notes Series PDF

Cell biology is defined as the branch of biology which deals with the study of cells. This branch comprises the study regarding shape, size, types, composition, division, and growth of the cells. A cell is the basic and fundamental unit of life, which acts as a building block of the organisms, hence it is crucial to study all the concepts related to cell biology thoroughly.

Discovery of cells

  • In 1665, cell discovered by Robert Hooke
  • He actually observed only cell walls
  • Hooke coined the term cell
  • He wrote his findings in a book Micrographia
  • In 1672, Anton Von Leuwenhoek first saw and described live cell
  • Robert Brown later discovered the nucleus

All the organisms are composed of micrometre-sized blocks. These building blocks are termed as cells. Cells are the living building blocks that differentiate living organisms from non-living things. An organism can be made up of a single cell (a Unicellular organism) or many cells (Multicellular organisms). Cells are the fundamental and structural units of life.

Anton Von Leeuwenhoek was the first scientist who noticed and termed the unit as cell. The discovery of microscopes and other instruments then further helped to determine the structural components of the cell. Robert Hook later coined the term ‘nucleus’.

Cells combine together to form a tissue, tissues combine together to form an organ, organs together form an organ system, organ systems and rest of the components then form an organism. Hence, a cell is the basic unit of life.

Characteristics of Cells

Following are the various essential characteristics of cells:

  • Cells provide structure and support to the body of an organism.
  • The cell interior is organised into different individual organelles surrounded by a separate membrane.
  • The nucleus (major organelle) holds genetic information necessary for reproduction and cell growth.
  • Every cell has one nucleus and membrane-bound organelles in the cytoplasm.
  • Mitochondria, a double membrane-bound organelle is mainly responsible for the energy transactions vital for the survival of the cell.
  • Lysosomes digest unwanted materials in the cell.
  • Endoplasmic reticulum plays a significant role in the internal organisation of the cell by synthesising selective molecules and processing, directing and sorting them to their appropriate locations.

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By Team Learning Mantras