II. Purpose                 : To identify the structure of potato cell which is stained by iodine.

  To identify  the osmosis of cell

III Hypothesis            :1.iodine could identify the glucose which is products of      photosynthesis,the polimeritation of glucose producing chloroplast and leucoplast.

2. Osmosis are examples of passive transport where by ions or molecules driven by thermal motion move down concentration gradients set up between solutions separated by biological membranes in living systems

Osmosis  is defined as the net movement of water or any small molecule across a partially permeable membrane from a region of low concentration to a region of higher concentration.

· Water will flow from the low concentration to the high

concentration.

· The potato cube in high concentration solution will gain and increase

in mass.

· The potato cube in low concentration solution will loose and decrease

in mass.    

1.Potato

2.Microscope

3.Water

4.Iodine solution

5.Cutter

1. Potato

2.10 % salt solution

3. Distillated water

4. two tubes

5. stopwatch (watch)

6. Cutter

1.Slice a  thin of potato

2.Put it on to glass slide

3.Add with water

4.Cover it with cover slip

5.Observe the slide under law and high power of microscope

6.Take the same way and change water with dropping of iodine solution

1.Obtain two label of test tubes

2,Place salt solution in one tube,and water solution in the other tube.

3.Place a slice of potato which has 1 cm length into both of tubes

4.Allow them to stay in the tubes for 30 minutes

5.Observe the differences between the two slices of potato.

That’s potato cell under medium power (100x). The little clear circles are actually the leucoplasts.These organel store starch in plant cells.After stained with iodine, it turns dark blue/black when in contact with starch.

The potato slice which is placed into a cup of pure water is bubbling because there also is some water already inside the cells .The water in the cup is more concentrated than the water in the cells.

The slice which is placed in a cup of very salty water is reducing because the water in the cup is a low concentration because the salt forces the water molecules apart from each other

the iodine solution reveals the presence of leucoplast,granules of coiled starch within the cells with the dark blue/black color.

Water molecules will move from an area of higher concentration to an area of lower concentration.The area of lower concentration is inside the cells so the water will move there.The cell membrane is semi-permeable so the water molecules can get through.The cell will expand as the water flows in.As all the cells expand, the potato slice will expand and become more rigid.

The salt makes the water in the cup a lower concentration than the water in the cells.The water molecules will move out of the cells to spread into the salty water in the cup.As water leaves the cells, they will shrink.As the cells shrink, the slice will shrink and become more flexible.

So, our hypothesis were correct that water flows from the less concentrated to the more concentrated solution, and therefore the mass increases in the more concentrated solution.This phenomenon is named Osmosis.

I.  Title                        : Diffusion

II. Purpose                : To identify how molecular size influences the rate of diffusion

III.Hypothesis            : Diffusion occurs in solutions consisting of particles air and  drinking water are both examples of solutions consisting of molecules/mixtures of different types of particles.Molecules are in constant random motion. If molecules of one type are concentrated in one area, they will move until they are evenly distributed throughout the container.

1.Petri dishes

2.agar

3.ink

4.Stop watch

            1. Obtain two Petri dishes, one empty and one with agar.

            2. Place water in the empty one so that it covers the bottom of the dish.

            3. Add a drop of ink to the center of each dish.

            4. Measure the size of each drop across the diameter, and record the time.

            5. Observe what happens.

6. When the ink nears the edge of the dish of water, measure and record the    diameter of the spot and record the time.           

 VI. Recording observation :

The ink sinks to the bottom of the Petri dish because it is more dense than water. Overtime, the ink at the bottom spreads upward. It moves from a region of high concentration to one of low concentration.The ink has been diluted with water to produce paler shade. Diffusion eventually stops when the concentration of water and ink is same.

The rate of diffusion is affected by properties of the cell, the diffusing molecule and the surrounding solution. The rate of diffusion increases as the concentration molecule. In contrast, if the concentration of the molecules are low, the rate of diffusion will be low. When differences in concentration no longer exist, diffusion stop

I.                   Title              : Structure of cell

II.                Purpose        : To Identify the structure of rhoe discolor,cassava,and protist

III.             Hypothesis   : The cell organel of plant:  a. cell wall

b. plastids

c. central vacuole

d. plasmodesmata

e. mitochondria

f. nucleus

g. golgi apparatus

h. etc.

 

1.Rhoediscolor

2.Cassava stem

3.Water pond

4.Cutter

5.Microscope

6.Aquades

1. Slice rhoediscolor into a small piece

            2. Place it onto glass slide

            3. Drop aquades.

            4. Cover with cover slip.

            5. Observe with microscope.

6. Do the same way with cassava stem and water pond.

Protists is used to refer to unicellular eukaryotes. Eukaryotes are a very diverse group, and their cell structures are equally diverse. Many have cell walls; many do not. Many have chloroplasts, derived from primary, secondary, or even tertiary endosymbiosis; and many do not. Some groups have unique structures, such as the cyanelles of the glaucophytes, the haptonema of the haptophytes, or the ejectisomes of the cryptomonads. Other structures, such as pseudopods, are found in various eukaryote groups in different forms, such as the lobose amoebozoans or the reticulose foraminiferans.

Reproduction

Plant cells are quite different from the cells of the other eukaryotic organisms. Their distinctive features are:

 * A large central vacuole (enclosed by a membrane, the tonoplast), which maintains the cell's turgor and controls movement of molecules between the cytosol and sap

    * A primary cell wall containing cellulose, hemicellulose and pectin, deposited by the protoplast on the outside of the cell membrane; this contrasts with the cell walls of fungi, which contain chitin, and the cell envelopes of prokaryotes, in which peptidoglycans are the main structural molecules

    * The plasmodesmata, linking pores in the cell wall that allow each plant cell to communicate with other adjacent cells; this is different from the functionally analogous system of gap junctions between animal cells.

    * Plastids, especially chloroplasts that contain chlorophyll, the pigment that gives plants their green color and allows them to perform photosynthesis

    * Higher plants, including conifers and flowering plants (Angiospermae) lack the flagellae and centrioles that are present in animal cells.