Tag: cell : the basis of life

Questions Related to cell : the basis of life

Who first propounded the cell theory stating that all living things are made up of cells or of material formed by cells?

  1. Asa Gray

  2. Matthias Jakob Schleiden

  3. Theodor Schwann

  4. Alfred Russel Wallace


Correct Option: B,C
Explanation:

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.

So the correct option is 'Mathias Jacob Schleiden and Theodor Schwann'.

Who proposed a modification in the cell theory?

  1. Schleiden and Schwann

  2. Rudolf Virchow

  3. Robert Hooke

  4. Marcello Malpighi


Correct Option: B
Explanation:

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.

The Latin phrase omnis cellula e cellula refers to a cellular principle. Which of the following statements is the best translation of this phrase?

  1. The cell is the basic unit of all structures.

  2. All cells arise only from pre-existing cells.

  3. Tissues are composed of similar cells.

  4. All organisms consists of one or more cells.


Correct Option: B
Explanation:
Cell theory was postulated by Theodor Schwann and Matthias Schleiden in 1838. It includes the following points-
All living organisms are composed of one or more cells.
The cell is the most basic unit of life. The third was added by Rudolf Virchow in 1855, which stated: "Omnis cellula e cellula" which means all cells arise only from pre-existing cells.

_________ was the first one to observe free living cells. The term cell was given by  ___________ . Cell theory was proposed by  _________ and ________ . All cells arise from pre-existing cells was suggested by ____________ .
Select the correct sequence of names to complete the above paragraph.

  1. Robert Hooke, Virchow, Anton von Leeuwenhoek, Schleiden, Schwann

  2. Anton von Leeuwenhoek, Robert Hooke, Schleiden, Schwann, Virchow

  3. Robert Hooke, Virchow, Schleiden, Schewann, Anton von Leeuwenhoek

  4. Anton von Leeuwenhoek, Virchow, Schleiden, Schewann, Robert Hooke


Correct Option: B
Explanation:

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.