Even with the naked eye, or even better under a magnifying glass, you can see that the pulp of a ripe watermelon, tomato, or apple consists of very small grains or grains. These are cells - the smallest “building blocks” that make up the bodies of all living organisms.
What are we doing? Let's make a temporary microslide of a tomato fruit.
Wipe the slide and cover glass with a napkin. Use a pipette to place a drop of water on the glass slide (1).
What to do. Using a dissecting needle, take a small piece of fruit pulp and place it in a drop of water on a glass slide. Mash the pulp with a dissecting needle until you obtain a paste (2).
Cover with a cover glass and remove excess water with filter paper (3).
What to do. Examine the temporary microslide with a magnifying glass.
What we are seeing. It is clearly visible that the pulp of the tomato fruit has a granular structure (4).
These are the cells of the pulp of the tomato fruit.
What we do: Examine the microslide under a microscope. Find individual cells and examine them at low magnification (10x6), and then (5) at high magnification (10x30).
What we are seeing. The color of the tomato fruit cell has changed.
A drop of water also changed its color.
Conclusion: The main parts of a plant cell are the cell membrane, the cytoplasm with plastids, the nucleus, and vacuoles. The presence of plastids in the cell is a characteristic feature of all representatives of the plant kingdom.
Please write a conclusion about a piece of fruit pulp under a magnifying glass
- Even with the naked eye, or even better under a magnifying glass, you can see that the flesh of a ripe watermelon consists of very small grains, or grains. These are cells - the smallest “building blocks” that make up the bodies of all living organisms.
If you examine the pulp of a tomato or watermelon with a microscope magnifying approximately 56 times, round transparent cells are visible. In apples they are colorless, in watermelons and tomatoes they are pale pink. The cells in the “mush” lie loosely, separated from each other, and therefore it is clearly visible that each cell has its own membrane, or wall.
Conclusion: A living plant cell has:
1. Living contents of the cell. (cytoplasm, vacuoles, nucleus)
2. Various inclusions in the living contents of the cell. (deposits of reserve nutrients: protein grains, drops of oil, starch grains.)
3. Cell membrane, or wall. (It is transparent, dense, elastic, does not allow the cytoplasm to spread, and gives the cell a certain shape.) - Even with the naked eye, or even better under a magnifying glass, you can see that the flesh of a ripe watermelon consists of very small grains, or grains. These are cells - the smallest “building blocks” that make up the bodies of all living organisms.
If you examine the pulp of a tomato or watermelon with a microscope magnifying approximately 56 times, round transparent cells are visible. In apples they are colorless, in watermelons and tomatoes they are pale pink. The cells in the “mush” lie loosely, separated from each other, and therefore it is clearly visible that each cell has its own membrane, or wall.
Conclusion: A living plant cell has:
1. Living contents of the cell. (cytoplasm, vacuoles, nucleus)
2. Various inclusions in the living contents of the cell. (deposits of reserve nutrients: protein grains, drops of oil, starch grains.)
3. Cell membrane, or wall. (It is transparent, dense, elastic, does not allow the cytoplasm to spread, and gives the cell a certain shape.) - the cells are very large
- Cells are seen better when viewed under a magnifying instrument.
1. Answer the question.
Why do I use magnifying devices?
- Answer: To study small objects.
Hand magnifier
2. Consider a hand-held magnifying glass. Write the names of its parts and the functions they perform.
3. Take pieces of tomato pulp (watermelon, apple). Examine them with the naked eye. What do you get out?
- Answer: Soft thin peel and seeds.
4. Examine the pieces with a magnifying glass. What do you see?
- Answer: Pulp cells.
5. Conclusion
- Answer: The magnifying glass is so strong that you can see cells that are not visible to the naked eye.
Light microscope
1) Examine the microscope. Find the main parts of the microscope. Using the textbook text and drawing, find out what their meaning is.
2) Familiarize yourself with the rules of working with a microscope. Learn to set the light, achieve good illumination of the field of view.
3) Check each other’s knowledge of the rules for using a microscope.
4) Determine how many times the microscope magnifies the image of the object. (300 times. Depends on the microscope)
5) Practice the sequence of actions when working with a microscope.
Students of general education institutions study the cellular structure of plant organisms in the sixth grade. Biological laboratories equipped with observational equipment use an optical magnifying glass or microscopy. Cells of tomato pulp microscope are studied in practical classes and arouse genuine interest among schoolchildren, because it becomes possible, not in the pictures of a textbook, but to see with one’s own eyes the features of the microworld that are not visible to the naked eye with optics. The branch of biology that systematizes knowledge about the totality of flora is called botany. The subject of the description are also tomatoes, which are described in this article.
Tomato, according to modern classification, belongs to the dicotyledonous pynopetalous family of Solanaceae. A perennial herbaceous cultivated plant, widely used and grown in agriculture. They have a juicy fruit that is consumed by humans due to its high nutritional and taste qualities. From a botanical point of view, these are polyspermous berries, but in non-scientific activities, in everyday life, people often classify them as vegetables, which is considered erroneous by scientists. It is distinguished by a developed root system, a straight branching stem, and a multi-locular generative organ weighing from 50 to 800 grams or more. They are quite high in calories and healthy, increase the effectiveness of the immune system and promote the formation of hemoglobin. They contain proteins, starch, minerals, glucose and fructose, fatty and organic acids.
Preparation of a microslide for examination under a microscope.
The preparation must be microscoped using the bright field method in transmitted light. Fixation with alcohol or formaldehyde is not done; living cells are observed. The sample is prepared using the following method:
- Using metal tweezers, carefully remove the skin;
- Place a sheet of paper on the table, and on it a clean rectangular glass slide, in the center of which drop one drop of water with a pipette;
- Using a scalpel, cut off a small piece of flesh, spread it over the glass with a dissecting needle, and cover the top with a square cover slip. Due to the presence of liquid, glass surfaces will stick together.
- In some cases, tinting with a solution of iodine or brilliant green can be used to increase contrast;
- Viewing starts at the lowest magnification - a 4x objective and a 10x eyepiece are used, i.e. it turns out 40 times. This will ensure the maximum viewing angle, allow you to correctly center the microsample on the stage and quickly focus;
- Then increase the magnification to 100x and 400x. At larger zooms, use the fine focusing screw in 0.002 millimeter increments. This will eliminate image shake and improve clarity.
What organelles can be seen in tomato pulp cells under a microscope:
- Granular cytoplasm - internal semi-liquid environment;
- Limiting plasma membrane;
- The nucleus, which contains genes, and the nucleolus;
- Thin connecting threads - strands;
- Single-membrane organelle vacuole responsible for secretion functions;
- Crystallized chromoplasts of bright color. Their color is influenced by pigments - it ranges from reddish or orange to yellow;
Recommendations: educational models are suitable for examining tomatoes - for example, Biomed-1, Levenhuk Rainbow 2L, Micromed R-1-LED. At the same time, use the lower LED, mirror or halogen backlight.