Question

Give an activity to prepare temporary mount of leaf peels, tip of roots of onion or peels of onions of different sizes.

Answer 1

Aim of the experiment: To prepare a temporary mount on peels of onions of different sizes.

Materials required :

1. A small piece from an onion bulb, forceps, watch glass, glass slide, water, safranin solution, coverslip, mounting needle, compound microscope.

Procedure :

1. We can take a small piece from an onion bulb.
2. Now, we can peel off the skin which is known as the epidermis from the concave side of the onion by using forceps.
3. Now place the skin layer immediately in a watch glass containing water.
4. Now we can take a glass slide and put a drop of water on it. Then we can transfer a small piece of the peel from the watch glass to the slide.
5. Make sure that the peel is laying perfectly flat on the slide.
6. Now we put a drop of safranin solution on the peel and cover it with a coverslip with the help of a mounting needle.
7. Now we have prepared a temporary mount of onion peel.
8. We can observe this prepared slide under the low power and high power of a compound microscope.

Diagram :

Observation:

1. These small microscopic structures are the basic building units of the onion bulb. These structures are called cells.

Conclusion:

1. The epidermis layer of the onion is composed of cells.
2. Each cell contains a cell wall enclosing a vacuole, a nucleus that is found inside the cell.