Juhi Mishra is teaching live on Unacademy Plus
Diagram of Cell Cell membrane Lysosome Mitochondrion Endoplasmic reticulum Vacuolar membrane Nucleolus Vacuole Nuclear Plastid Centrioles Golgi body Cytoplasm membrane Nucleus Chromatin
A. The cell is the basic unit of structure & function B. The cell is the smallest unit that can still carry on all life processes C. Both unicellular (one celled) and multicellular (many celled) organisms are composed of cells
D. Before the 17th century, ndo one knew cells existed E. Most cells are too small to be seen with the unaided eye F. In the early 17th century microscopes were inventedt& cells were seen for the 1st time G. Anton Von Leeuwenhoek,;a Dutchman, made the 1st hand held microscope & viewed microscopic organisms in water & bacteria from his teeth
H. In 1665, an English scientist named Robert Hooke made an improved microscope and viewed thin slices of cork viewing plant cell walls I. Hooke named what he saw "cells"
J. In the 1830's, Matthias Schleiden (botanist studying plants) & Theodore Schwann (zoologist studying animals)
K. In 1855, Rudolf Virchow stated that cells only arise from pre- existing cells L. Virchow's idea contradicted the idea of spontaneous generation (idea that nonliving things could give rise to organisms) M. The combined work of Schleiden, Schwann, & Virchow is known as the Cell Theory Schwann Schleiden Virchow
II. Principles of the Cell Theory A. All living things are made of one or more cells B. Cells are the basic unit of structure & function in organisms C. Cells come only from the reproduction of existing cells