Plant Tissue Culture
Class 12 · Biotechnology
4 ideas in Class 12 Biotechnology, explained in plain words, with games and quizzes to practise.
Totipotency and Explants
Part of: The PTC System
Plant cells stay flexible: given the right food and signals, one living piece can rebuild roots, stems and leaves. Growers therefore start from small starter bits like leaf bits, bud tips, embryos or seed leaves, kept germ-free on synthetic food in controlled air, light and warmth.
Why it matters. This flexibility powers every later trick from rapid cloning to germ-free plants. Knowing which bits start best helps you predict what a culture can become.
Key words
- totipotency
- : The ability of one living cell to rebuild a whole plant.
- explant
- : The starter piece placed onto culture food.
- aseptic
- : Fully free of unwanted germs.
- in vitro
- : Grown in glass vessels under lab control.
- regeneration
- : Rebuilding of full organs from cultured cells.
Try it in two minutes
- State the superpower in one line: one living piece can rebuild all parts.
- Name starter bits: leaf bits, bud tips, embryos, seed leaves.
- Ask why germ-free food and steady air, light and warmth matter.
Try at home. List three starter bits and the plant each could rebuild.
Media and Hormones
Part of: The PTC System
Culture food mimics soil in a jar: mineral salts, sugar fuel, vitamins, a firming agent and growth signals. Two signal families steer shape: one pushes rooting, the other pushes new stems, and their ratio decides which organs form. Mild acidity also matters for firmness and salt uptake.
Why it matters. Wrong mixes stall or deform cultures, wasting weeks. Reading recipes and ratios lets you fix pale, rootless or stemless cultures fast.
Key words
- MS medium
- : A standard culture-food recipe with salts and vitamins.
- auxin
- : A signal family that pushes rooting.
- cytokinin
- : A signal family that pushes new stems.
- gelling agent
- : The firmer that sets liquid food into jelly.
- pH
- : A scale telling how acidic or basic the food is.
Try it in two minutes
- List food parts: salts, sugar, vitamins, firmer, signals.
- Ask which signal pushes roots and which pushes new stems.
- Ask what the ratio decides when both signals sit in one jar.
Try at home. Write one food recipe with a root-push and a stem-push ratio.
Culture Types
Part of: Cultures and Uses
One starter can travel many routes. Whole bits grow as organ cultures, wound tissue forms shapeless callus lumps, stirred cells float as suspensions, wall-free cells fuse as protoplasts, and embryo-like dots grow into plantlets that can be packed as synthetic seeds.
Why it matters. Each route serves a goal: lumps for bulk, floats for even dosing, wall-free cells for fusing distant parents, embryo dots for sowing. Matching route to goal saves failed attempts.
Key words
- callus
- : A shapeless lump of dividing wound-tissue cells.
- cell suspension
- : Free cells stirred evenly in liquid food.
- protoplast
- : A plant cell with its wall removed.
- somatic embryo
- : An embryo-like dot that grows a plantlet.
- synthetic seed
- : A packed embryo dot sown like a seed.
Try it in two minutes
- Order routes from whole bits down to wall-free cells.
- Ask which route floats for even dosing.
- Ask which route fuses two parents into one cell.
Try at home. Draw four routes from one starter and name each goal.
Uses of Tissue Culture
Part of: Cultures and Uses
Tissue culture pays off in fields and factories. Bud-tip regrowth clones elites fast, tip culture frees stocks from viruses, fused cells birth distant hybrids, haploid routes speed pure lines, and stirred cells brew extra medicines and flavours. Cultured lines also vary usefully for selecting tougher crops.
Why it matters. These uses turn lab skill into harvests and products. Knowing which use fits which need helps you advise growers and makers correctly.
Key words
- micropropagation
- : Rapid cloning of plantlets from small starters.
- somatic hybridisation
- : Fusing body cells of two parents into one line.
- cybrid
- : A fused cell mixing one nucleus with another's outer matter.
- haploid culture
- : Growing plants with a single chromosome set.
- secondary metabolite
- : A useful plant-made chemical beyond basic needs.
Try it in two minutes
- Match each need to its use: many copies, clean stocks, distant cross, pure lines, brews.
- Ask why clones beat seeds for elite copying.
- Ask why stirred cells can out-yield parent plants for brews.
Try at home. Advise one grower: name the use that fits their need.
What your child will practise
- Culture Types: Space Quick Fire (Quick Fire)
- Media and Hormones: Ocean Puzzle (Clue Puzzle)
- Media and Hormones: Ocean Quick Fire (Quick Fire)
- Totipotency and Explants: Jungle Quick Fire (Quick Fire)
- Uses of Tissue Culture: Candy Puzzle (Clue Puzzle)
- Quiz: Culture Types (8 questions)
- Quiz: Media and Hormones (8 questions)
- Quiz: Totipotency and Explants (8 questions)
- Quiz: Uses of Tissue Culture (8 questions)