Sameer wants to observe Rhizopus under microscope. For this 1) What are preparatory activities he has to do ? ii) What procedure does he follow ? And What precautions should he take ?
A. I) To observe Rhizopus he has to do following preparatory activities:
- He has to grow Rhizopus or common mould on his own in a controlled environment.
- Take a bread slice, leave in open air for about an hour, place the bread in plastic bag.
- Sprinkle water over it to have dampness then seal the bag, leaving some air
inside, place it in a dark warm place. *
- After 2-3 days, you will find black patches (Or) thread like growth with masses of black, grey and green fine dotted structures on it.
if) Materials required : Mould sample, plain glass slide, coverslip, water, disposable gloves, microscope, tooth pick.
- Place a drop of water in the centre of the slide.
- Using a toothpick, scrape very little of the mould and place it on the drop of water.
- Take the cover slip and set it at an angle to the slide, so that one edge of it, touches the water drop, then carefully lower it over the drop so that the cover slip covers the specimen without trapping air bubbles underneath.
- Use the corner of a tissue paper or blotting paper to blot up any excess water at the edges of the cover slip.
- View the slide with a compound microscope first observe under low power. Observation:
a) The common bread mould consists of fine thread like projections called hyphae and thin stems having knob like structures called Sporangia.
b) Each sporangium contains hundreds of minute spores.
c) When the sporangium bursts, the tiny spores are dispersed in air.
i) Keep away from mould who is suffering from allergies and asthma.
ii) Do not touch mould with bear hands. If you touch it be sure to thoroughly wash your hands afterwards.