1.1 and 1.2 Flashcards
What are the capabilities of unicellular organisms?
- Independent existence
- Performing essential functions of life
Who was the first person to see and describe a live cell?
Anton Von Leeuwenhoek
Who discovered the nucleus?
Robert Brown
How did the invention and improvement of the microscope contribute to our understanding of cells?
- Revealed all the structural details of the cell
- Electron microscope provided even higher resolution images
Who examined plants and discovered that all plants are composed of different kinds of cells?
Matthias Schleiden
What did Theodore Schwann discover about cells?
He discovered that cells have a thin outer layer called the plasma membrane.
Q: What did Schwann conclude about plant cells?
He concluded that plant cells have a unique characteristic: the presence of a cell wall.
Q: What hypothesis did Schwann propose based on his observations?
He proposed that the bodies of animals and plants are composed of cells and products of cells.
Q: Who formulated the cell theory?
Matthias Schleiden and Theodore Schwann together formulated the cell theory.
Q: Who explained how new cells are formed?
Rudolf Virchow explained that cells divide and new cells are formed from pre-existing cells.
Q: What are the two main principles of the modern cell theory?
- All living organisms are composed of cells and their products.
- Cells arise from pre-existing cells.
Q: What is the dense membrane-bound structure inside a cell that contains chromosomes?
Nucleus
What is the semi-fluid matrix occupying the volume of a cell called?
Cytoplasm
Q: What is the outer boundary of a plant cell called?
Cell wall
Q: What is the outer membrane of a human cheek cell called?
Cell membrane