English
A cell is a tiny factory: the nucleus is the manager with the rule book, mitochondria are the power generators, the membrane is the security gate, and in plants the cell wall is the strong outer fence.
Part of Karnataka State Board Class 9 Science on Lipi
This chapter is free. Every subject of Karnataka · KSEEB · Class 9 is one module: ₹499 + GST a month →The cell is the unit of life
English
Robert Hooke first saw cells in cork in 1665. The cell theory says all organisms are made of cells and every cell comes from an existing cell.
Prokaryotic vs eukaryotic
English
Bacteria are prokaryotic: their DNA floats free, with no membrane-bound organelles. Plant, animal and fungal cells are eukaryotic and far more organised.
Animal vs plant cell
English
Both share a nucleus, cytoplasm, membrane, mitochondria and ribosomes. Plants add a cellulose cell wall, chloroplasts for photosynthesis and a large central vacuole.
The membrane controls traffic
English
Small molecules like oxygen cross by diffusion and water by osmosis. The cell wall, by contrast, is fully permeable and only gives support.
Listen to this section
Uses your saved EN voice · Narration settings
Point 1
Point 2
Point 3
Point 4
Point 5
Point 6
Listen to this section
Uses your saved EN voice · Narration settings
Point 1
The cell is the basic unit of structure and function in all living things.
Point 2
Each organelle has a specific job, and the parts work together.
Point 3
Plant and animal cells share a common plan but differ in key features.
Listen to this section
Uses your saved EN voice · Narration settings
सामान्य भूल
✕ The cell wall and the cell membrane are the same thing.
✓ The membrane is selectively permeable and is in every cell; the cell wall is a rigid cellulose layer outside the membrane, found only in plant (and fungal/bacterial) cells.
सामान्य भूल
✕ Animal cells have a small vacuole, so vacuoles are a plant-only feature.
✓ Animal cells can have small, temporary vacuoles; the plant feature is a single large permanent vacuole.
सामान्य भूल
✕ All plant cells have chloroplasts.
✓ Only cells that photosynthesise have chloroplasts; root and onion-bulb cells have none because they are underground in the dark.
सामान्य भूल
✕ Mitochondria make energy.
✓ Mitochondria release energy already stored in glucose by aerobic respiration; energy cannot be created.
Listen to this section
Uses your saved EN voice · Narration settings