ANSWER KEY- THE FUNDAMENTAL UNIT OF LIFE

The Fundamental Unit of Life
The Cell Theory: “All plants and animals are composed of
cells”
 A cell is the basic unit of life




Microscopy

,  Cells were first discovered by Robert Hooke in 1665
 He observed the cells in a cork slice with a primitive
microscope
 Leeuwenhoek in 1674 used an improved microscope to
discover living cells
 In 1831 Robert Brown observed the nucleus in the cell
 Purkinje in 1839 called the fluid inside the cell-
‘Protoplasm’
 In 1855 Virchow said all cells arise from pre- existing
cells
 The electron microscope was discovered in 1940 and ever
since, we can observe complex cell organelles.

Check up on Microscopy
Circle the correct answer
1. All plants and animals are composed of:
A. tissues
B. organs
C. cells
D. molecules
2. Who first discovered cells in cork?
A. Robert Brown
B. Robert Hooke
C. Leeuwenhoek
D. Virchow
3. Which scientist first observed living cells?
A. Robert Hooke
B. Robert Brown
C. Leeuwenhoek
D. Virchow

, 4. The scientist who discovered the nucleus was:
A. Robert Hooke
B. Brown
C. Leeuwenhoek
D. Virchow
5. The statement “All cells arise from pre-existing cells” was said
by:
A. Robert Hooke
B. Robert Brown
C. Virchow
D. Leeuwenhoek

Answer the following questions
1. Why is safranin solution added to the onion peel slide?




2. What is a cell?




3. Explain why staining is important when observing cells.




4. Create a timeline of cell discoveries and write one sentence
about what they discovered