Class 9 Science — Chapter 5: The Fundamental Unit of Life

What you'll learn

• ▸Discovery of the Cell
• ▸The Cell Theory
• ▸Unicellular vs. Multicellular Organisms
• ▸Cell Diversity in Shape and Size
• ▸Structural Organization of a Cell
• ▸The Plasma Membrane and Selective Permeability
• ▸Diffusion and Gaseous Exchange
• ▸Osmosis and Water Movement
• ▸Cell Behavior in Different Solutions

Chapter Summary

--- PAGE 1 --- 0964CH05 Chapter 5 The Fundamental Unit of Life While examining a thin slice of cork, Robert Hooke saw that the cork resembled the structure of a honeycomb consisting of many little compartments. Cork is a substance which comes from the bark of a tree. This was in the year 1665 when Hooke made this chance observation through a self-designed microscope. Robert Hooke called these boxes cells. Cell is a Latin word for ‘a little room’. This may seem to be a very small and insignificant incident but it is very important in the history of science. This was the very first time that someone had observed that living things appear to consist of separate units. The use of the word ‘cell’ to describe these units is being used till this day in biology. Let us find out about cells. 5.1 What are Living Organisms Made Up of? Activity 5.1 • Let us take a small piece from an onion bulb. With the help of a pair of forceps, we can peel off the skin (called epidermis) from th…

Practice Questions from this Chapter

Tap "Get Solution" on any question to ask our AI tutor.

1. Describe how cells work. Get Solution →
2. Identify different cell types. Get Solution →
3. Compare plant and animal cells. Get Solution →
4. Who is credited with first discovering cells in 1665 while observing cork? Get Solution →
5. The term 'cell' originates from a Latin word meaning what? Get Solution →
6. Which scientist discovered the nucleus within the cell in 1831? Get Solution →
7. What is the outermost covering of an animal cell that separates its contents from the external environment? Get Solution →
8. What is the process called where substances move from a region of high concentration to a region of low concentration? Get Solution →

Did you know?

• 💡 The largest known single cell is an ostrich egg, measuring up to 6 inches long.
• 💡 Your body replaces almost all its cells every 7 to 10 years.
• 💡 There are more bacterial cells living in your body than human cells.
• 💡 Some human nerve cells can be over a meter long, stretching to your toes.
• 💡 A single drop of pond water can contain thousands of unicellular organisms.

Frequently Asked Questions

Related Chapters