R
Rishtaara
Science · Class 8

Cell Structure and Functions

Prokaryotic vs eukaryotic cell; organelles and their functions.

4 sections15–25 min read6 MCQs · 2 examples

Chapter Overview

Plant cells have cell wall and chloroplasts; animal cells do not.

The cell is the basic unit of life. This chapter covers cell structure — cell membrane, cytoplasm, nucleus, organelles — and differences between plant and animal cells.

Cell Structure

  • Cell membrane: selective boundary
  • Cytoplasm: jelly-like; organelles suspended
  • Nucleus: control centre; contains chromosomes (DNA)
  • Vacuole: large in plant cells; stores sap

Organelles

  • Mitochondria: powerhouse — respiration
  • Chloroplast: photosynthesis (plant only)
  • Cell wall: rigid outer layer (plant only)
  • ER, Golgi, ribosomes: protein synthesis and transport

Plant vs Animal Cell

  • Plant: cell wall, chloroplasts, large central vacuole
  • Animal: centrioles; no cell wall or chloroplasts
  • Both have nucleus, mitochondria, membrane

Solved Examples

Step-by-step solutions — read each step before checking the final answer.

Cell discovery

Who discovered cells and how?

  1. 1Robert Hooke saw cork cells in microscope (1665)
  2. 2Coined term 'cell' from small rooms
  3. 3Later Leeuwenhoek saw living cells

Answer

Robert Hooke — cork slice

Organelle function

Why are mitochondria called powerhouse?

  1. 1Site of cellular respiration
  2. 2ATP energy produced here
  3. 3Present in both plant and animal cells

Answer

Energy release from glucose

Key Points to Remember

  • Unicellular: Amoeba, bacteria; multicellular: humans
  • Tissue: group of similar cells
  • Organ: group of tissues

Exam Tips

  • Draw and label plant and animal cells
  • Compare plant and animal cell in table
  • State functions of nucleus and chloroplast

Practice MCQs — Cell Structure and Functions

Test your understanding with topic-wise multiple choice questions. Explanations appear after each answer.

Question 1 of 6Score: 0/0

Cell is the ___ unit of life.