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4/2025 1 Dr. KRIM M. Chapter N?1 Overview of cell biology 1.It is the smallest structurally and functionally viable entity that possesses distinctive characteristics such as assimilation and self-reproduction.Cell definition Cell as the morphological and physiological unit of life serves as the fundamental building block shared among all living organisms.The study of cell biology originated in the 17th century largely propelled by advancements in microscopy.Consequently, the cell constitutes the fundamental unit for biological and biochemical activities.

4/2025
1 Dr. KRIM M.
Chapter N°1
Overview of cell biology

1. Cell definition
   Cell as the morphological and physiological unit of life serves as the fundamental building block
   shared among all living organisms. It is the smallest structurally and functionally viable entity
   that possesses distinctive characteristics such as assimilation and self-reproduction.
   Consequently, the cell constitutes the fundamental unit for biological and biochemical activities.
   The study of cell biology originated in the 17th century largely propelled by advancements in
   microscopy. In 1665, Robert Hooke made a significant discovery when he observed the cell
   walls of cork and coined the term "cell" to describe their appearance. Around the same time the
   Dutch naturalist Antonie van Leeuwenhoek constructed his own microscopes and utilized them
   to document various microscopic structures including spermatozoa numerous protists and blood
   cells.


2. Living beings classification
   Living beings can be classified into different categories based on their characteristics and
   evolutionary relationships. One common classification system is the five-kingdom classification
   which categorizes living organisms into five main groups: Kingdom Monera Kingdom Protista
   Kingdom Fungi Kingdom Plantae and Kingdom Animalia.
    Kingdom Monera consists of unicellular prokaryotic organisms specifically bacteria and
   archaea. These organisms lack a true nucleus and membrane-bound organelles.
    Kingdom Protista includes unicellular and some multicellular eukaryotic organisms.
   This diverse group encompasses a wide range of organisms such as algae protozoa and
   slime molds.
    Kingdom Fungi consists of multicellular eukaryotic organisms that obtain nutrients
   through absorption. Fungi include mushrooms molds and yeasts.
    Kingdom Plantae is composed of multicellular photosynthetic organisms including
   plants trees shrubs and mosses. They have specialized tissues for conducting water
   nutrients and photosynthesis.
    Kingdom Animalia encompasses multicellular eukaryotic organisms which are
   heterotrophic and have the ability to move. This kingdom includes animals ranging fro