Tag: cell as structural and functional unit

Cell theory is the idea that the cell is the fundamental structural and functional unit of all living organisms and that new cells are formed from other existing cells. This theory is one of the foundations of modern biology. First formulated in the early 1800s in landmark publications by Mathias Jacob Schleiden and Theodor Schwann, the foundations of this theory began in mid-1600s through advances in microscopy. Today, it is held that all organisms are composed of one or more cells, all vital functions of an organism occur within cells, and cells contain the hereditary information necessary for regulating cell functions and for transmitting information to the next generation of cells.

Rudolf Virchow modified the cell theory and gave the concept of 'Omnis cellule e cellulae'- which means new cells develop by the division of the pre-existing cells. This is called the theory of cell lineage or common ancestry.

Antonie Philips van Leeuwenhoek was first to observe the living cell. He is commonly known as "the Father of Microbiology", and considered to be the first microbiologist. He is best known for his work on the improvement of the microscope and for his contributions towards the establishment of microbiology.
The cell was first discovered by Robert Hooke in 1665, which can be found to be described in his book Micrographia. In this book, he gave 60 observations in detail of various objects under a coarse, compound microscope. One observation was from very thin slices of bottle cork. Hooke discovered a multitude of tiny pores that he named "cells". 
Cell theory was eventually formulated in 1838. This is usually credited to Matthias Schleiden and Theodor Schwann.  Cell theory has become the foundation of biology and is the most widely accepted explanation of the function of cells.
Virchow is credited with many important discoveries. His most widely known scientific contribution is his cell theory, which built on the work of Theodor Schwann. He was one of the first to accept the work of Robert Remak, who showed the origins of cells was the division of pre-existing cells.

• The first man to witness a live cell under a microscope was Anton Von Leeuwenhoek.
• Robert Brown was responsible for discovering the nucleus of a cell.
• Matthias Jakob Schleiden started that all parts of the plant organism are composed of different kinds of cell.
• Theodor Schwann studied that cells had a thin outer layer which is today known as plasma membrane. He also concluded that the plant shows the presence of a cell wall is a unique character of plant cells.
• So, the correct option is " A-(i), B-(iii), C-(iv), D-(ii).

In 1665 Robert Hooke published his book Micrographia which detailed his observations and included drawings. This book was the first important work on microscopy, the study of objects through a microscope. At the end of the book, there are observations of the stars and moon as seen through a telescope.

Leeuwenhoek, a Dutch naturalist was the first to observe and describe various unicellular microorganisms like bacteria, protozoa etc. along with animal cells like RBCs, muscles fibres, through a specialized lens designed by him.

Rudolf Virchow modified the cell theory and gave the concept of 'omnis cellula e cellulae' - means new cells develop by division of the pre-existing cells. This is called theory of cell lineage or common ancestry.

• The  cork cells seen by Robert Hooke were published in his book  'Micrographia'. It was published in January 1665. It was the first book which illustrate the microscopic view of plants and insects. 
  
• Origin of species is a work of scientific literature by Charles Darwin . It was published on 24 November 1859.
• Species Plantarum list every species of plant known at that time. This is a book by Carl Linnaeus , originally published in 1753. 
• Genera Plantarum is a fifth edition of book Species Plantarum .