The Fundamental Unit Of Life Class 9 CBSE Notes - Chapter 5

Life, as we know it, took billions of years to evolve. From the very first precursor of life to the multitude of multicellular organisms that we see around us today, the most basic unit of all these is the cell.

What are Living Organisms Made Up of?

Cells are termed as the fundamental, structural unit of life. Every living organism is made up of billions of cells that have a variety of roles and functions to play. However, individual cells also contribute whole organisms like amoeba, paramecium etc.

These cells contain many structures called organelles that perform various roles which help the cell to sustain itself. The common cell organelles are:

  1. Nucleus
  2. Cell wall
  3. Cytoplasm
  4. Endoplasmic reticulum
  5. Golgi apparatus
  6. Lysosomes
  7. Mitochondria
  8. Plastids
  9. Vacuoles

However, certain cell organelles are specific to certain cells. For instance, cell walls and vacuoles are exclusive to plant cells. Lysosomes are seen only in animal cells, but they perform similar functions as vacuoles in plant cells.

Question from The Fundamental Unit Of Life Class 9 Notes

  1. How does a plant cell differ from an animal cell?
  2. Differentiate between a eukaryotic cell and a prokaryotic cell.
  3. What would be the outcome in a scenario where a rupture occurs in the plasma membrane?
  4. Define osmosis.
  5. How does an amoeba acquire food?
  6. Growth and repair require which type of cell division?

Further Reading:-

Practise This Question

Which of the following elements has an isotope that does not have a neutron in its nucleus?