science Flashcards
cells (25 cards)
What is the cell theory?
The cell theory is a scientific theory that states all living organisms are composed of cells, the cell is the basic unit of life, and all cells arise from pre-existing cells.
True or False: The cell theory states that cells can spontaneously generate from non-living matter.
False
Who are the main scientists associated with the development of cell theory?
Matthias Schleiden, Theodor Schwann, and Rudolf Virchow.
Fill in the blank: According to cell theory, the __________ is the basic unit of life.
cell
What does the first principle of cell theory state?
All living organisms are made up of one or more cells.
What does the second principle of cell theory state?
The cell is the basic unit of structure and organization in organisms.
What does the third principle of cell theory state?
All cells arise from pre-existing cells.
Multiple Choice: Which of the following is NOT a part of the cell theory? A) All living things are made of cells B) Cells arise from non-cellular materials C) Cells are the basic unit of life D) All cells come from pre-existing cells
B) Cells arise from non-cellular materials
True or False: Viruses are considered cells according to cell theory.
False
What type of microscope was critical in the development of cell theory?
Light microscope
Fill in the blank: Cell theory was developed in the __________ century.
19th
What is the significance of Rudolf Virchow’s contribution to cell theory?
He proposed that all cells come from pre-existing cells (Omnis cellula e cellula).
Short answer: Explain why the cell is considered the basic unit of life.
Because all life processes occur within cells, and they are the smallest units that can carry out these processes.
Multiple Choice: Which of the following statements is true about cells? A) They can only arise from other cells B) They can spontaneously generate C) They are not necessary for life D) They are only found in multicellular organisms
A) They can only arise from other cells
True or False: All cells have a nucleus.
False
What are prokaryotic cells?
Cells that lack a membrane-bound nucleus and organelles, such as bacteria.
What are eukaryotic cells?
Cells that have a membrane-bound nucleus and organelles, such as plant and animal cells.
Fill in the blank: The cell theory applies to __________ organisms.
all living
Short answer: Describe one limitation of cell theory.
Cell theory does not apply to viruses, which are not considered living organisms.
What advancement in science helped confirm the principles of cell theory?
The invention of the microscope.
True or False: All cells are the same size and shape.
False
Fill in the blank: The cell theory was formally established in the year __________.
1855
Multiple Choice: Which of the following is a key feature of prokaryotic cells? A) Membrane-bound organelles B) Nucleus C) Circular DNA D) Multicellularity
C) Circular DNA
What role did Matthias Schleiden play in the development of cell theory?
He proposed that all plants are made of cells.
