Discover the beauty of life: vein bookmark making activity

Activity purpose

? Guide students to discover the beauty and wonder of life;

? Stimulate students' interest in biology.

Activity time, class

65438+February 65438+April 2020; Class 29, Senior One.

Activities to be prepared

1 induction cooker, 1 stainless steel pot, 1 water tray, 1 plastic gloves, 1 protective glasses, 1 glass rod, 3 beakers, 60 pairs of disposable gloves, 1 lab clothes, 2 Shuang Mu.

Teacher Zhang Wenqing, the head teacher of the laboratory, prepares the laboratory, lab clothes, chemicals, plastic gloves, water pans, glasses, beakers, etc. And bring your own induction cooker, stainless steel pot, goggles, wooden chopsticks, plastic gloves, old newspapers, a lot of leaves, various dyes, ribbons, etc. Students bring their own old toothbrushes.

Activity process

Select the blade. Choose thick veins, generally evergreen woody plants are better. Such as osmanthus leaves, heather leaves, papaya leaves, eucalyptus branches and leaves, tea and so on.

Boil the leaves with 10% sodium hydroxide solution. Boil the prepared lye in a stainless steel pot or an iron pot, then add a proper amount of washed leaves and boil. At this time, use ordinary wooden chopsticks to rotate gently to prevent the leaves from overlapping and being heated evenly. The windows should be blocked for ventilation, because there is a bad smell when the leaves are boiled.

? Cook for about 5 minutes. After the leaves turn black, take a leaf and put it in a water dish filled with clear water. Wash it carefully with clear water. (Note: In this operation, leaves should not be taken and placed directly by hand to prevent sodium hydroxide from corroding hands. Take and place with tweezers or clips. )

When the residual lye on the leaves is washed clean, take it out, put the leaves flat on the experimental platform, gently brush off the rotten mesophyll on both sides of the leaves along the vein direction with a small tube brush or a soft-haired old toothbrush, and rinse with small flow of tap water until only the veins are left.

Brush the pulse sheet, rinse it, and put it on the glass sheet to dry. Air-dried to a semi-dry and semi-wet state, coated with all kinds of dyes, and then sandwiched in old books and newspapers, and then taken out after absorbing moisture, it can be used as veins bookmarks. After drying, tie a colorful ribbon on the petiole to make a clear, colorful, beautiful and practical vein bookmark. If you want to preserve it better, you can take it to the photo studio for plastic molding, which will also make the bookmark more beautiful. It is also suitable as a bookmark and is more suitable for giving to friends and relatives. Although the gift is small, it is also very popular.

After the experiment, the sixth group packed up the experimental platform and laboratory hygiene.

Activity summary

This activity of making vein bookmarks is well prepared, simple to operate and high in success rate. Students have a strong interest and enjoy it, which has been widely praised by students and left them with good memories. Students also find that life is so beautiful and moving through the wonderful context, and guide students to cherish life opportunities. Vein bookmarks, who do activities, are to be sent to plastic photo studios and encourage students to give them as gifts to their families. I believe that the gifts I made will definitely bring surprises to their families and promote parent-child communication and gratitude education. The disadvantage of the activity is that the first pot of leaves is cooked for too short a time, so it is difficult to make a veins bookmarks, which wastes a lot of time. It is much easier and faster to make fully boiled leaves at the back. After learning the lesson, you don't have to worry about boiling the leaves. There are too many photos taken during the activity, but not enough videos, so we should learn a lesson.

High school study time is tight and stressful, and there is little time and opportunity for activities. I'm worried that the well-received research trip will be cancelled because of the epidemic. Senior one and senior two are the prime time for student activities, and there is no chance for senior three, so we should make good use of the last semester of senior one and senior two to organize some high-quality class activities. I hope that after graduating from high school for many years, students can still think of some people, activities or things that impress them, and I hope that these activities can leave some beautiful colors for their children's youth.