Questions and Answers
Robert Hooke observed tiny packets called ______ in cork.
cells
Cells are generally smaller than ______ mm.
1
The exchange of nutrients and metabolic wastes occurs through the cell's ______.
surface
Small cells have a larger surface area relative to their ______.
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The first use of a simple microscope to study cells was attributed to ______.
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The invention of simple and practical ______ made it possible for the cell to be discovered.
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Anton Van Leeuwenhoek observed moving unicellular ______ under the microscope.
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Francesco Redi’s experiment proved that life cannot spontaneously arise from an ______ object.
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A ______ can easily manipulate various cellular activities once it has invaded the host cell.
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Cell theory states that the cell is the ______ unit of life.
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Study Notes
Cell Discovery and Microscopy
- Simple and practical microscopes facilitated the discovery of cells.
- Robert Hooke first observed cells using a microscope on cork from oak tree bark.
Cell Theory Principles
- Cells are the smallest unit capable of sustaining life and performing necessary functions: metabolism, homeostasis, and reproduction.
- Each cell is a system that enables nutrient exchange and waste elimination through its surface.
- Cells need a sufficient surface area relative to volume for effective material exchange.
Importance of Cell Size
- Most cells are less than 1 mm, with some as small as 1 µm; smaller structures measured in nanometers.
- The small size of cells allows for visibility under microscopes for study.
- Small cells generally have a higher surface area-to-volume ratio, facilitating nutrient entry and waste removal.
Historical Contributions to Cell Theory
- Hans and Zacharias Janssen invented the first primitive microscope in the late 16th century, leading to microscopic studies.
- Antonio Van Leeuwenhoek observed moving unicellular microorganisms under a microscope and contributed to understanding life beyond visible organisms.
- Francesco Redi's experiments demonstrated that life does not arise spontaneously from inanimate matter, specifically in experiments with rotten meat.
Virus and Cellular Life
- A virus's ability to manipulate cellular activities upon invading a host cell raises questions about its status as a living organism; viruses cannot reproduce independently outside a host.
Real-Life Application of Cell Theory
- Acne (e.g., pimples) reflects the principle that all cells arise from pre-existing cells, as the body produces new skin cells that can become clogged and lead to acne development.
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Description
Test your understanding of cell theory and the role of microscopes in biology. This quiz challenges you with questions related to observations made through microscopes and the fundamentals of cell theory. Answer carefully and enhance your knowledge of cellular structures and functions.
