Day : Date :

Activity : 2.3 (The general structure of an onion cell) (textbook page 37)Aim : Apparatus and material : light microscope, glass slide, cover slip, razor blade, needle, dropper, forceps, filter paper, iodine solution, big onion.

Procedure :1. The inner epidermal layer of an onion scale leaf was peeled off carefully by using

a razor blade and a pair of forceps.2. It was placed on a glass slide. A drop of iodine solution was added to it. 3. A needle was used to carefully lowered the cover slip onto the inner epidermal

layer of the onion.4. Some filter paper was used to absorb any excess iodine.5. The onion cell was looked through the microscope.6. The structure of one onion cell was drawn.7. The following cell structures were identified and labelled:

Cell wall, cell membrane, cytoplasm, protoplasm, nucleus and cell vacuoles.

Observation :

Questions : ( Number 1 – 4) – textbook page 381. What is the shape and colour of onion cell?

Onion cell has a fixed shape and brown/yellow colouring.2. How are the cells arranged?

The cells are arranged in the same way as bricks in a brick wall.3. Which part of the onion cell is the cell wall?

Outer part.4. Which parts of the cell make up the protoplasm?

Cytoplasm and nucleus.

Conclusion :Plant cell (onion cell) has ___________, __________________, ________________, __________________, _________________ and _____________.

*** draw Figure 2.2- preparing a slide of an onion epidermal cell

ONION CELL

(textbook page 37)**

Day : Date :

Activity : 2.4 (The general structure of a human cheek cell) (textbook page 39)

Aim :

Apparatus and material : refer textbook

Procedure :1. A drop of methylene blue was put on a glass slide.2. The inside of cheek was scraped carefully with the blunt end of a toothpick.3. The scrapings were placed on the glass slide. A drop of water was added.4. The cover slip was lowered gently onto the glass slide.5. Any excess methylene blue was absorbed with some filter paper.6. The structure of a cheek cell that observe under the microscope was drawn.7. The following cell structures were labelled :

Cell membrane, nucleus, cytoplasm and protoplasm.

Observation :

Questions : ( Number 1 – 3) textbook page 391. What is the shape of the cheek cells that you see? How are they arranged?

Cheek cells do not have regular shapes. They are not uniform in size.2. Identify the cell membrane?

Cell membrane is thin layer surrounding the cell.3. Can you see the nucleus?

Yes.Conclusion :

Animal cell (cheek cell) has ___________, __________________ and _____________.

*** draw Figure 2.4(textbook page 39)***

CHEEK CELL