Question

Write the procedure to grow Rhizopus in the lab. Write the observation and precautions, materials required.

Answer 1

Hint: Rhizopus is a cosmopolitan filamentous fungus found in soil, decaying fruit and vegetables, animal feces and old bread.

Complete answer:
The procedure to grow Rhizopus in the lab is:
- Take the cotton swabs and run them over areas that have dust.
- Then rub the dust from the cotton swab over the first bread slice and repeat the same with the other bread slices.
- Then, seal the three bread slices inside three transparent sealable bags and put a sticker on the three bags, and write down using a marker on them.
- On the first sticker write "Sample #1 - Dark Closet"; on the second write "Sample #2 - Refrigerator", and on the third write "Sample #3 - Under Light" and keep the first sample in a dark closet, second in a corner of the refrigerator where it doesn't get disturbed, and the third one in an area of the house which is most of the time brightly lit.
- Now, take the remaining two samples. Before we seal them in the bags we add either lemon juice/ water/ apple juice/ salt/ sugar. Keep these two samples in a place where they don't get disturbed.

The materials required are:
1. slices of bread
2. 5 transparent sealable bags
3. Gloves
4. Mask
5. Sticky labels
6. Marker
7. Magnifying glass
8. 5 - 7 cotton swabs
9. Lemon juice/ water/ apple juice/ salt/ sugar (at least two of these items are required)

The observations are as follows:
It is observed that the five bread samples every alternate day at a fixed time of the day (say 2 pm). It is important that we observe them every alternate day without fail, and note down the observations in a table. The observations can be their physical appearance like colour, shape, amount of growth per day, texture, etc. We can also observe the mold under the magnifying glass (usually thread-like structures are seen on top of which there is a circular shape).

Precautions: We should use masks and gloves for safety. We should properly dispose of the bags (without opening) after the experiment is over.

Note: It is to be noted that Rhizopus are characterized by a body of branching mycelium composed of three types of hyphae: stolons, rhizoids and usually unbranching sporangiophores.