The experiment name verifies the absorption of roots.

The purpose of the experiment will be to design an observation experiment; Know that roots can be absorbed.

Experimental equipment: well-grown plants, glass and peanut oil.

experimental procedure

1. Add a proper amount of water to the glass.

2. Put the plants in the glass.

3. Drop peanut oil into the cup to prevent the water from evaporating.

4. Fix the plants with rubber plugs (drilling holes in the middle and cutting them in half is beneficial to fix the plants), and mark the cup wall.

5. Put the plant in a sunny place and observe the change of liquid level in the glass.

The experimental phenomenon is that the liquid level in the glass will gradually drop.

The experimental results show that roots can be absorbed. While absorbing water, it also absorbs nutrients dissolved in water.

Experimental explanation

1, glass can be replaced by flask, and the scale can be observed directly without scribing.

2. Peanut oil evaporates and can be replaced by cotton.

3. The rubber plug can be replaced by plasticine.

Lesson 3 Leaves of Plants

Experimental name: separation of chlorophyll

Experimental purposes The leaves of most plants are green because they contain chlorophyll.

Experimental equipment: conical flask, alcohol, beaker (containing water), tripod, asbestos net, alcohol lamp, matches, absorbent cotton (cotton).

experimental procedure

1, put some green leaves in the conical flask, and then add 95% alcohol until the leaves are submerged.

2. Put the conical flask into a big beaker filled with hot water.

3. Put the asbestos net on the tripod, then put the beaker on the water, and light the alcohol lamp to heat it.

After a while, you will see that the colorless alcohol in the conical bottle turns completely green, and these green substances are chlorophyll.

The conclusion of the experiment is that most leaves are green because they contain chlorophyll.

Experiments show that chlorophyll is insoluble in water and soluble in alcohol. When heated and boiled, chlorophyll will run into alcohol.

Improvement: If this experiment is done in groups, it is not safe. If you demonstrate, it is not conducive to students' observation. Students can do it at home. Methods: Put the white wine in a mineral water bottle, put the green leaves in the bottle, put them in a pot with water, heat them on the stove and observe them carefully. The effect is very good.

Lesson 4 Plant Stem