Cell: The Unit of Life – Introduction | CHEMASH Biology

The Cell is the most basic structural, functional, and biological unit of all living organisms. The chapter “Cell: The Unit of Life” forms the foundation of Biology and is extremely important for Class 9, Class 11, NEET, Olympiads, and all competitive exams (2026).

Table of Contents

• What is a Cell?
• Discovery of Cell
• Cell Theory
• Importance of Cells
• Exam-Oriented Notes (2026)
• MCQs with Answers
• Frequently Asked Questions
• Why Choose CHEMASH?

What is a Cell?

A cell is the smallest unit of life capable of carrying out all vital functions such as metabolism, growth, respiration, and reproduction. All living organisms—plants, animals, and microorganisms— are made up of one or more cells.

Cells may exist independently as in unicellular organisms (Amoeba, Bacteria), or collectively as multicellular organisms (humans, plants).

Discovery of Cell

The discovery of the cell marked a major milestone in biological sciences.

• 1665 – Robert Hooke observed dead cork cells using a compound microscope.
• 1674 – Anton van Leeuwenhoek observed living cells.
• 1838–1839 – Schleiden and Schwann proposed the Cell Theory.

Cell Theory

Cell Theory explains the fundamental principles of cell biology:

1. All living organisms are composed of cells.
2. The cell is the basic structural and functional unit of life.
3. All cells arise from pre-existing cells.

Importance of Cells

• Cells control all metabolic activities.
• They store genetic material (DNA).
• They enable growth, repair, and reproduction.
• Understanding cells helps in medical science and biotechnology.

Exam-Oriented Notes (2026)

• Cell = smallest living unit ✔
• Hooke observed dead cells ✔
• Living cells observed by Leeuwenhoek ✔
• Cell Theory is frequently asked (1–3 marks) ✔

MCQs

Q1. Who discovered the cell?
a) Darwin
b) Robert Hooke
c) Mendel
d) Watson

Answer: b) Robert Hooke

Q2. The smallest unit of life is:
a) Tissue
b) Organ
c) Cell
d) Atom

Answer: c) Cell

Q3. Which organism is unicellular?
a) Human
b) Frog
c) Amoeba
d) Tree

Answer: c) Amoeba

Frequently Asked Questions

Q. Why is the cell called the unit of life?
A. Because all life processes occur inside cells.

Q. Is this chapter important for NEET?
A. Yes, it is a foundation chapter for Biology.

Why Choose CHEMASH?

CHEMASH is a trusted and student-friendly education platform providing Biology, Chemistry, and Physics tuition for all classes.

• Low-budget tuition
• Experienced & friendly teachers
• Problem-solving focused approach
• Exam-oriented teaching (2026 ready)
• Trusted by students & parents

CHEMASH – Learn Smart. Score High.

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