Totipotency & Tissue Culture

Question 1

Equipment required (12)

Answer 1

• Seeds of white mustard
• agar
• distilled water
• damp sponge
• cling film
• McCartney bottles
• weighing scales
• plastic tray
• 250ml beaker
• glass rod
• scissors
• sunny window sill

Question 2

Outline the method

Answer 2

sprinkle seeds on damp sponge and allow to germinate. Use when just starting to unfold their cotyledons (seed leaves). Make up Agar gel and pour 2cm height of gel into McCartney bottles and allow to set. With sharp scissors, cut the tops off just below the shoot apex (including the cotyledons). This is called an explants. Push the stem of the explant into the gel (making sure cotyledons don’t touch agar) cover with cling film and place on sunny windowsill. Observe over 10 days.

Question 3

Possible evaluation issues (2)

Answer 3

• Unwanted pathogens growing in the gel as it is a good source of water and nutrients
• Wrong part of the plant cut and inserted into gel.