Why did a drop of water change its color. What does a tomato look like under a magnifying glass?

Task 1. Examination of onion skin.

4. Draw a conclusion.

Answer. The skin of an onion consists of cells that fit tightly together.

Task 2. Examination of tomato cells (watermelon, apple).

1. Prepare a microslide of the fruit pulp. To do this, use a dissecting needle to separate a small piece of pulp from a cut tomato (watermelon, apple) and place it in a drop of water on a glass slide. Spread the dissecting needle in a drop of water and cover with a coverslip.

Answer. What to do. Take the pulp of the fruit. Place it in a drop of water on a glass slide (2).

2. Examine the microslide under a microscope. Find individual cells. Look at the cells at low magnification and then at high magnification.

Mark the color of the cell. Explain why the drop of water changed its color and why did this happen?

Answer. The color of the flesh cells of a watermelon is red, and that of an apple is yellow. A drop of water changes its color because it receives the cell sap contained in the vacuoles.

3. Draw a conclusion.

Answer. A living plant organism consists of cells. The contents of the cell are represented by semi-liquid transparent cytoplasm, which contains a denser nucleus with a nucleolus. The cell membrane is transparent, dense, elastic, does not allow the cytoplasm to spread, and gives it a certain shape. Some areas of the shell are thinner - these are pores, through which communication between cells occurs.

Thus, the cell is the structural unit of the plant

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, vacuole, 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.)

Magnifier, microscope, telescope.

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. Also, the pulp of a tomato fruit under a magnifying glass consists of cells similar to rounded grains.

2.

Think

Tasks

6) Consider.

Cell activity:

3, 5, 1, 4, 2.

14. Complete the definition.

15. Fill out the diagram.

16. Fill out the table.

In this chapter you will learn

You will learn

Prepare microslides;

3. Using the textbook, study the structure of hand-held and tripod magnifiers. Label their main parts in the pictures.

4. Examine pieces of fruit pulp under a magnifying glass. Sketch what you see. Sign the drawings.

5. After completing the laboratory work “The design of a microscope and methods of working with it” (see pp. 16-17 of the textbook), label the main parts of the microscope in the figure.

6. In the drawing, the artist mixed up the sequence of actions when preparing a microslide. Indicate with numbers the correct sequence of actions and describe the progress of preparing the microslide.
1) Place 1-2 drops of water on the glass.
2) Remove a small piece of transparent scale.
3) Place a piece of onion on the glass.
4) Cover with a cover slip and examine.
5) Stain the preparation with iodine solution.
6) Consider.

7. Using the text and pictures of the textbook (p. 2), study the structure of a plant cell, and then complete the laboratory work “Preparation and examination of a preparation of onion scale skin under a microscope.”

8. After completing the laboratory work “Plastids in the cells of the Elodea leaf” (see p. 20 of the textbook), write captions for the drawing.

Conclusion: the cell has a complex structure: there is a nucleolus, cytoplasm, membrane, nucleus, vacuoles, pores, chloroplasts.

9. What color can plastids be? What other substances found in the cell give the plant organs different colors?
Green, yellow, orange, colorless.

10. Having studied paragraph 3 of the textbook, fill out the diagram “Cell life processes”.
Cell activity:
1) The movement of the cytoplasm - promotes the movement of nutrients in the cells.
2) Breathing – absorbs oxygen from the air.
3) Nutrition - from the intercellular spaces through the cell membrane they come in the form of nutrient solutions.
4) Reproduction - cells are capable of division, the number of cells increases.
5) Growth - cells increase in size.

11. Consider the division diagram of a plant cell. Use numbers to indicate the sequence of stages (stages) of cell division.

12. During life, changes occur in a cell.

Use numbers to indicate the sequence of changes from the youngest to the oldest cell.
3, 5, 1, 4, 2.

How does the youngest cell differ from the oldest cell?
The youngest cell has a nucleus, a nucleolus, and the oldest one does not.

13. What is the significance of chromosomes? Why is their number in a cell constant?
1) They transmit hereditary characteristics from cell to cell.
2) As a result of cell division, each chromosome copies itself. Two identical parts are formed.

14. Complete the definition.
A tissue is a group of cells that are similar in structure and perform the same functions.

15. Fill out the diagram.

16. Fill out the table.

17. Label the main parts of a plant cell in the picture.

18. What was the significance of the invention of the microscope?
The invention of the microscope was of great importance. With the help of a microscope, it became possible to see and examine the structure of the cell.

19. Prove that a cell is a living part of a plant.
A cell can: eat, breathe, grow, reproduce. And these are signs of living things.

Magnifier, microscope, telescope.

Question 2. What are they used for?

They are used to enlarge the object in question several times.

Laboratory work No. 1. Construction of a magnifying glass and using it to examine the cellular structure of plants.

1. Examine a hand-held magnifying glass. What parts does it have? What is their purpose?

A hand magnifying glass consists of a handle and a magnifying glass, convex on both sides and inserted into a frame. When working, the magnifying glass is taken by the handle and brought closer to the object at a distance at which the image of the object through the magnifying glass is most clear.

2. Examine with the naked eye the pulp of a semi-ripe tomato, watermelon, or apple. What is characteristic of their structure?

The pulp of the fruit is loose and consists of tiny grains. These are cells.

It is clearly visible that the pulp of the tomato fruit has a granular structure. The apple's pulp is slightly juicy, and the cells are small and tightly packed together. The pulp of a watermelon consists of many cells filled with juice, which are located either closer or further away.

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. Also, the pulp of a tomato fruit under a magnifying glass consists of cells similar to rounded grains.

Laboratory work No. 2. The structure of a microscope and methods of working with it.

1. Examine the microscope. Find the tube, eyepiece, lens, tripod with stage, mirror, screws. Find out what each part means. Determine how many times the microscope magnifies the image of the object.

Tube is a tube that contains the eyepieces of a microscope. An eyepiece is an element of the optical system facing the eye of the observer, a part of the microscope designed to view the image formed by the mirror. The lens is designed to construct an enlarged image with accurate reproduction of the shape and color of the object of study. A tripod holds the tube with an eyepiece and objective at a certain distance from the stage on which the material being examined is placed. The mirror, which is located under the object stage, serves to supply a beam of light under the object in question, i.e., it improves the illumination of the object. Microscope screws are mechanisms for adjusting the most effective image on the eyepiece.

When working with a microscope, the following rules must be observed:

1. You should work with a microscope while sitting;

2. Inspect the microscope, wipe the lenses, eyepiece, mirror from dust with a soft cloth;

3. Place the microscope in front of you, slightly to the left, 2-3 cm from the edge of the table. Do not move it during operation;

4. Open the aperture completely;

5. Always start working with a microscope at low magnification;

6. Lower the lens to the working position, i.e. at a distance of 1 cm from the slide;

7. Set the illumination in the field of view of the microscope using a mirror. Looking into the eyepiece with one eye and using a mirror with a concave side, direct the light from the window into the lens, and then illuminate the field of view as much as possible and evenly;

8. Place the microspecimen on the stage so that the object being studied is under the lens. Looking from the side, lower the lens using the macroscrew until the distance between the lower lens of the lens and the microspecimen becomes 4-5 mm;

9. Look into the eyepiece with one eye and rotate the coarse aiming screw towards yourself, smoothly raising the lens to a position at which the image of the object can be clearly seen. You cannot look into the eyepiece and lower the lens. The front lens may crush the cover glass and cause scratches;

10. Moving the specimen by hand, find the desired location and place it in the center of the microscope’s field of view;

11. After finishing work with high magnification, set the magnification to low, raise the lens, remove the specimen from the work table, wipe all parts of the microscope with a clean napkin, cover it with a plastic bag and put it in a cabinet.

3. Practice the sequence of actions when working with a microscope.

1. Place the microscope with the tripod facing you at a distance of 5-10 cm from the edge of the table. Use a mirror to shine light into the opening of the stage.

3. Using the screw, smoothly lower the tube so that the lower edge of the lens is at a distance of 1-2 mm from the specimen.

4. Look into the eyepiece with one eye without closing or squinting the other. While looking through the eyepiece, use the screws to slowly lift the tube until a clear image of the object appears.

Question 1. What magnifying devices do you know?

Hand magnifier and tripod magnifier, microscope.

Question 2. What is a magnifying glass and what magnification does it provide?

A magnifying glass is the simplest magnifying device. A hand magnifying glass consists of a handle and a magnifying glass, convex on both sides and inserted into a frame. It magnifies objects 2-20 times.

A tripod magnifying glass magnifies objects 10-25 times. Two magnifying glasses are inserted into its frame, mounted on a stand - a tripod. A stage with a hole and a mirror is attached to the tripod.

Question 3. How does a microscope work?

Magnifying glasses (lenses) are inserted into the viewing tube, or tube, of this light microscope. At the upper end of the tube there is an eyepiece through which various objects are viewed. It consists of a frame and two magnifying glasses. At the lower end of the tube is placed a lens consisting of a frame and several magnifying glasses. The tube is attached to a tripod. An object table is also attached to the tripod, in the center of which there is a hole and a mirror under it. Using a light microscope, you can see an image of an object illuminated by this mirror.

Question 4. How to find out what magnification a microscope gives?

To find out how much the image is magnified when using a microscope, you need to multiply the number indicated on the eyepiece by the number indicated on the objective lens you are using. For example, if the eyepiece provides 10x magnification and the objective provides 20x magnification, then the total magnification is 10 x 20 = 200x.

Think

The main principle of operation of a light microscope is that light rays pass through a transparent or translucent object (object of study) placed on the stage and hit the lens system of the objective and eyepiece. And light does not pass through opaque objects, and therefore we will not see an image.

Tasks

Learn the rules of working with a microscope (see above).

Using additional sources of information, find out what details of the structure of living organisms can be seen with the most modern microscopes.

The light microscope made it possible to examine the structure of cells and tissues of living organisms. And now, it has been replaced by modern electron microscopes, which allow us to examine molecules and electrons. And an electron scanning microscope allows you to obtain images with a resolution measured in nanometers (10-9). It is possible to obtain data concerning the structure of the molecular and electronic composition of the surface layer of the surface under study.

Laboratory work No. 1

The device of magnifying devices

Target: study the structure of a magnifying glass and microscope and how to work with them.

Equipment: magnifying glass, microscope, tomato, watermelon, apple fruits .

Progress

1. Consider a hand-held magnifying glass. What parts does it have? What is their purpose?

2. Examine with the naked eye the pulp of a semi-ripe tomato, watermelon, or apple. What is characteristic of their structure?

3. Examine pieces of fruit pulp under a magnifying glass. Draw what you see in your notebook and sign the drawings. What shape do the fruit pulp cells have?

The device of a microscope and methods of working with it.

Examine the microscope. Find a tube, an eyepiece, screws, a lens, a tripod with a stage, a mirror. Find out what each part means. Determine how many times the microscope magnifies the image of the object.

Familiarize yourself with the rules for using a microscope.

Procedure for working with a microscope.

Place the microscope with the tripod facing you at a distance of 5–10 cm from the edge of the table. Use a mirror to direct light through the hole in the stage.

Place the prepared preparation on the stage and secure the slide with clamps.

Using the screws, smoothly lower the tube so that the lower edge of the lens is at a distance of 1 - 2 mm from the specimen.

After use, put the microscope in its case.

A microscope is a fragile and expensive device. You must work with it carefully, strictly following the rules.

Laboratory work No. 2

Target

Equipment

Progress

Stain the preparation with iodine solution. To do this, apply a drop of iodine solution to a glass slide. Use filter paper on the other side to pull off excess solution.

Laboratory work No. 3

Preparation of microslides and examination of plastids under a microscope in the cells of elodea leaves, tomato fruits, and rose hips.

Target: prepare a microslide and examine the plastids in the cells of an elodea, tomato and rose hip leaf under a microscope.

Equipment: microscope, elodea leaf, tomato and rose hips

Progress

Draw the structure of an Elodea leaf cell.

Prepare cell preparations of tomato, rowan, and rose hips. To do this, transfer a particle of pulp into a drop of water on a glass slide with a needle. Use the tip of a needle to separate the pulp into cells and cover with a coverslip. Compare the cells of the fruit pulp with the skin cells of the onion scales. Note the color of the plastids.

Laboratory work No. 2

(structure of onion skin cells)

Target: study the structure of onion skin cells on a freshly prepared microslide.

Equipment: microscope, water, pipette, slide and cover glass, needle, iodine, bulb, gauze.

Progress

Look at Fig. 18 sequence of preparation of onion scale skin preparation.

Use a pipette to place 1 – 2 drops of water onto a glass slide.

Examine the prepared preparation at low magnification. Note which parts you see.

Examine the specimen at high magnification. Find a dark stripe surrounding the cell - the membrane, underneath it is a golden substance - the cytoplasm (it can occupy the entire cell or be located near the walls). The nucleus is clearly visible in the cytoplasm. Find the vacuole with cell sap (it differs from the cytoplasm in color).

Sketch 2 - 3 cells of onion skin. Label the membrane, cytoplasm, nucleus, vacuole with cell sap.

Laboratory work No. 4

Preparation of the preparation and examination under a microscope of the movement of the cytoplasm in the cells of the elodea leaf

Target: prepare a microscopic specimen of an elodea leaf and examine the movement of the cytoplasm in it under a microscope.

Equipment: freshly cut elodea leaf, microscope, dissecting needle, water, slide and cover glass.

Progress

State your conclusion.

Laboratory work No. 5

Examination under a microscope of finished micropreparations of various plant tissues

Target: examine prepared micropreparations of various plant tissues under a microscope.

Equipment: micropreparations of various plant tissues, microscope.

Progress

Set up the microscope.

Under a microscope, examine ready-made micropreparations of various plant tissues.

Note the structural features of their cells.

Read P. 10.

Based on the results of studying the micropreparations and the text of the paragraph, fill out the table.

Laboratory work No. 6.

Structural features of mucor and yeast

Target: grow mucor mold and yeast, study their structure.

Equipment: bread, plate, microscope, warm water, pipette, slide, cover slip, wet sand.

Conditions for the experiment: heat, humidity.

Progress

Mucor mold

Grow white mold on bread. To do this, place a piece of bread on a layer of damp sand poured into a plate, cover it with another plate and place it in a warm place. After a few days, a fluff consisting of small threads of mucor will appear on the bread. Examine the mold with a magnifying glass at the beginning of its development and later, when black heads with spores form.

Prepare a microspecimen of the mold fungus mucor.

Examine the microscopic specimen at low and high magnification. Find mycelium, sporangia and spores.

Draw the structure of the mucor mushroom and label the names of its main parts.

Yeast structure

Dissolve a small piece of yeast in warm water. Pipette and place 1 – 2 drops of water with yeast cells on a glass slide.

Cover with a cover slip and examine the preparation using a microscope at low and high magnification. Compare what you see with Fig. 50. Find individual yeast cells, look at the outgrowths on their surface - buds.

Draw a yeast cell and label the names of its main parts.

Based on the research conducted, formulate conclusions.

Formulate a conclusion about the structural features of the mucor fungus and yeast.

Laboratory work No. 7

The structure of green algae

Target: study the structure of green algae

Equipment: microscope, slide, unicellular algae (Chlamydomonas, Chlorella), water.

Progress

Place a drop of “blooming” water on a microscope slide and cover with a coverslip.

Examine unicellular algae at low magnification. Look for Chlamydomonas (a pear-shaped body with a pointed front end) or Chlorella (a spherical body).

Pull off some of the water from under the cover glass with a strip of filter paper and examine the algae cell at high magnification.

Find the membrane, cytoplasm, nucleus, and chromatophore in the algae cell. Pay attention to the shape and color of the chromatophore.

Draw a cell and write the names of its parts. Check the correctness of the drawing using the drawings in the textbook.

State your conclusion.

Laboratory work No. 8.

The structure of moss, fern, horsetail.

Target: study the structure of moss, fern, horsetail.

Equipment: herbarium specimens of moss, fern, horsetail, microscope, magnifying glass.

Progress

STRUCTURE OF MOSS.

Consider a moss plant. Determine the features of its external structure, find the stem and leaves.

Determine the shape, location. Size and color of leaves. Examine the leaf under a microscope and sketch it.

Determine whether the plant has a branched or unbranched stem.

Examine the tops of the stem to find male and female plants.

Examine the spore box. What is the importance of spores in the life of mosses?

Compare the structure of moss with the structure of algae. What are the similarities and differences?

Write down your answers to the questions.

STRUCTURE OF THE SPORING TAIL

Using a magnifying glass, examine the summer and spring shoots of horsetail from the herbarium.

Find the spore-bearing spikelet. What is the significance of spores in the life of horsetail?

Sketch the horsetail shoots.

STRUCTURE OF A SPORING FERN

Study the external structure of the fern. Consider the shape and color of the rhizome: the shape, size and color of the fronds.

Examine the brown tubercles on the underside of the frond with a magnifying glass. What are they called? What develops in them? What is the importance of spores in the life of a fern?

Compare ferns with mosses. Look for similarities and differences.

Justify that fern belongs to higher spore plants.

What are the similarities between moss, fern, horsetail?

Laboratory work No. 9.

The structure of needles and conifer cones

Target: study the structure of conifer needles and cones.

Equipment: needles of spruce, fir, larch, cones of these gymnosperms.

Progress

Consider the shape of the needles and their location on the stem. Measure the length and pay attention to the color.

Using the description of the characteristics of coniferous trees presented below, determine which tree the branch you are considering belongs to.

The needles are long (up to 5 - 7 cm), sharp, convex on one side and rounded on the other, sitting in twos together...... Scots pine

The needles are short, hard, sharp, tetrahedral, sit singly, cover the entire branch...... ……………….Spruce

The needles are flat, soft, blunt, have two white stripes on the other side……………………………… Fir

The needles are light green, soft, sit in bunches, like tassels, fall off for the winter…………………………………….. Larch

Consider the shape, size, and color of the cones. Fill the table.

Separate one scale. Familiarize yourself with the location and external structure of the seeds. Why is the studied plant called gymnosperm?

Laboratory work No. 10.

Structure of flowering plants

Target: study the structure of flowering plants

Equipment: flowering plants (herbarium specimens), hand magnifying glass, pencils, dissecting needle.

The sizes of the cells are so small that it is impossible to examine them without special devices. Therefore, magnifying devices are used to study the structure of cells.

Magnifier- the simplest magnifying device. A magnifying glass consists of a magnifying glass, which is inserted into a frame with a handle for ease of use. Magnifiers come in handheld and tripod types.

A hand-held magnifying glass (Fig. 3, a) can magnify the object in question from 2 to 20 times.

Rice. 3. Hand-held (a) and tripod (b) magnifiers

A tripod magnifying glass (Fig. 3, b) magnifies the object 10-20 times. The rules for working with a magnifying glass are very simple: the magnifying glass must be brought to the object of study at a distance at which the image of this object becomes clear.

Using a magnifying glass, you can see the shape of fairly large cells, but it is impossible to study their structure.

(from the Greek micros - small and skopeo - I look) - an optical device for viewing in an enlarged form small objects that are not visible to the naked eye. With its help, they study, for example, the structure of cells.

A light microscope consists of a tube, or tube (from the Latin tube - tube). At the top of the tube there is an eyepiece (from the Latin oculus - eye). It consists of a frame and two magnifying glasses. At the lower end of the tube there is a lens (from the Latin objectum - object), consisting of a frame and several magnifying glasses. The tube is attached to a tripod. The tube is raised and lowered using screws. There is also a stage on the tripod, in the center of which there is a hole and a mirror underneath it. The object examined on the slide is placed on the stage and secured to it using clamps (Fig. 4).

Rice. 4. Light microscope

The main principle of operation of a light microscope is that light rays pass through a transparent (or translucent) object of study, which is located on the stage, and fall on a system of objective lenses and an eyepiece, which magnify the image. Modern light microscopes can magnify images up to 3,600 times.

To find out how much the image is magnified when using a microscope, you need to multiply the number indicated on the eyepiece by the number indicated on the objective lens you are using. For example, if the number 8 is on the eyepiece and 20 on the lens, then the magnification factor will be 8 x 20 = 160.

Answer the questions

1. What instruments are used to study cells?
2. What are magnifying glasses and how much magnification can they provide?
3. What parts does a light microscope consist of?
4. How to determine the magnification given by a light microscope?

New concepts

Cell. Magnifier. Light microscope: eyepiece, lens.

Think!

Why can't we study opaque objects using a light microscope?

My laboratory

Some cells can be seen with the naked eye. These are the cells of the pulp of the fruits of watermelon, tomato, nettle fiber (their length reaches 8 cm), the yolk of a chicken egg - one large cell.

Rice. 5. Tomato cells under a magnifying glass

Examining the cellular structure of plants using the moon

1. Examine with the naked eye the pulp of tomato, watermelon, and apple fruits. What is characteristic of their structure?
2. Examine pieces of fruit pulp under a magnifying glass. Compare what you see with Figure 5, sketch it in your notebook, and sign the drawings. What shape do the fruit pulp cells have?

The structure of a light microscope and methods of working with it

1. Study the structure of the microscope using Figure 4. Find the tube, eyepiece, lens, tripod with stage, mirror, screws. Find out what each part means.
2. Familiarize yourself with the rules of using a microscope.
3. Practice the procedure for working with a microscope!

Rules for working with a microscope

• Place the microscope with the tripod facing you at a distance of 5-10 cm from the edge of the table. Use a mirror to shine light into the opening of the stage.
• Place the slide with the prepared preparation on the stage. Secure the slide with clamps.
• Using the screw, smoothly lower the tube so that the lower edge of the lens is at a distance of 1-2 mm from the specimen.
• Look into the eyepiece with one eye without closing or squinting the other. While looking through the eyepiece, use the screws to slowly lift the tube until a clear image of the object appears.
• After use, put the microscope in its case.
• A microscope is a fragile and expensive device: you must work with it carefully, strictly following the rules.

The first microscopes with two lenses were invented at the end of the 16th century. However, it was not until 1665 that the Englishman Robert Hooke used the microscope he had improved to study organisms. Examining a thin section of cork (the bark of a cork oak tree) through a microscope, he counted up to 125 million pores, or cells, in one square inch (2.5 cm). Hooke discovered the same cells in the core of elderberry and the stems of various plants. He gave them the name “cells” (Fig. 6).

Rice. 6. Microscope of R. Hooke and view of cork cells according to his own drawing

At the end of the 17th century. Dutchman Antonie van Leeuwenhoek designed a more advanced microscope, providing magnification up to 270 times (Fig. 7). With his help, he discovered microorganisms. Thus began the study of the cellular structure of organisms.

Rice. 7. Microscope by A. Leeuwenhoek.
A magnifying glass (a) is attached to the upper part of the metal plate. The observed object was located at the tip of a sharp needle (b). The screws served for focusing.

Current page: 2 (book has 7 pages total) [available reading passage: 2 pages]

Biology is the science of life, of living organisms living on Earth.

Biology studies the structure and vital functions of living organisms, their diversity, and the laws of historical and individual development.

The area of ​​distribution of life makes up a special shell of the Earth - the biosphere.

The branch of biology about the relationships of organisms with each other and with their environment is called ecology.

Biology is closely related to many aspects of human practical activity - agriculture, medicine, various industries, in particular food and light, etc.

Living organisms on our planet are very diverse. Scientists distinguish four kingdoms of living beings: Bacteria, Fungi, Plants and Animals.

Every living organism is made up of cells (with the exception of viruses). Living organisms eat, breathe, excrete waste products, grow, develop, reproduce, perceive environmental influences and react to them.

Each organism lives in a specific environment. Everything that surrounds a living being is called its habitat.

There are four main habitats on our planet, developed and inhabited by organisms. These are water, ground-air, soil and the environment inside living organisms.

Each environment has its own specific living conditions to which organisms adapt. This explains the great diversity of living organisms on our planet.

Environmental conditions have a certain impact (positive or negative) on the existence and geographical distribution of living beings. In this regard, environmental conditions are considered as environmental factors.

Conventionally, all environmental factors are divided into three main groups - abiotic, biotic and anthropogenic.

Chapter 1. Cellular structure of organisms

The world of living organisms is very diverse. To understand how they live, that is, how they grow, feed, and reproduce, it is necessary to study their structure.

In this chapter you will learn

About the structure of the cell and the vital processes occurring in it;

About the main types of tissues that make up organs;

About the structure of a magnifying glass, a microscope and the rules of working with them.

You will learn

Prepare microslides;

Use a magnifying glass and microscope;

Find the main parts of a plant cell on a micropreparation in the table;

Schematically depict the structure of a cell.

§ 6. Construction of magnifying devices

1. What magnifying devices do you know?

2. What are they used for?

If we break a pink, unripe tomato (tomato), watermelon or apple with loose pulp, we will see that the pulp of the fruit consists of tiny grains. This cells. They will be better visible if you examine them using magnifying devices - a magnifying glass or a microscope.

Magnifying device. Magnifier- the simplest magnifying device. Its main part is a magnifying glass, convex on both sides and inserted into the frame. Magnifiers come in handheld and tripod types (Fig. 16).

Rice. 16. Hand-held magnifying glass (1) and tripod magnifying glass (2)

Hand magnifier Magnifies objects by 2–20 times. When working, it is taken by the handle and brought closer to the object at a distance at which the image of the object is most clear.

Tripod magnifier Magnifies objects 10–25 times. Two magnifying glasses are inserted into its frame, mounted on a stand - a tripod. A stage with a hole and a mirror is attached to the tripod.

The device of a magnifying glass and using it to examine the cellular structure of plants

1. Examine a hand-held magnifying glass. What parts does it have? What is their purpose?

2. Examine with the naked eye the pulp of a semi-ripe tomato, watermelon, or apple. What is characteristic of their structure?

3. Examine pieces of fruit pulp under a magnifying glass. Draw what you see in your notebook and sign the drawings. What shape do the fruit pulp cells have?

The device of a light microscope. Using a magnifying glass you can see the shape of the cells. To study their structure, they use a microscope (from the Greek words “mikros” - small and “skopeo” - look).

The light microscope (Fig. 17) that you work with at school can magnify images of objects up to 3600 times. Into the telescope, or tube This microscope has magnifying glasses (lenses) inserted into it. At the upper end of the tube there is eyepiece(from the Latin word “oculus” - eye), through which various objects are viewed. It consists of a frame and two magnifying glasses.

At the lower end of the tube is placed lens(from the Latin word “objectum” - object), consisting of a frame and several magnifying glasses.

The tube is attached to tripod. Also attached to the tripod stage, in the center of which there is a hole and below it mirror. Using a light microscope, you can see an image of an object illuminated by this mirror.

Rice. 17. Light microscope

To find out how much the image is magnified when using a microscope, you need to multiply the number indicated on the eyepiece by the number indicated on the object being used. For example, if the eyepiece provides 10x magnification and the objective provides 20x magnification, then the total magnification is 10 × 20 = 200x.

How to use a microscope

1. Place the microscope with the tripod facing you at a distance of 5–10 cm from the edge of the table. Use a mirror to shine light into the opening of the stage.

2. Place the prepared preparation on the stage and secure the slide with clamps.

3. Using the screw, smoothly lower the tube so that the lower edge of the lens is at a distance of 1–2 mm from the specimen.

4. Look into the eyepiece with one eye without closing or squinting the other. While looking through the eyepiece, use the screws to slowly lift the tube until a clear image of the object appears.

5. After use, put the microscope in its case.

A microscope is a fragile and expensive device: you must work with it carefully, strictly following the rules.

The device of a microscope and methods of working with it

1. Examine the microscope. Find the tube, eyepiece, lens, tripod with stage, mirror, screws. Find out what each part means. Determine how many times the microscope magnifies the image of the object.

2. Familiarize yourself with the rules for using a microscope.

3. Practice the sequence of actions when working with a microscope.

CELL. MAgnifying glass. MICROSCOPE: TUBE, OCULAR, LENS, TRIPOD

Questions

1. What magnifying devices do you know?

2. What is a magnifying glass and what magnification does it provide?

3. How does a microscope work?

4. How do you know what magnification a microscope gives?

Think

Why can't we study opaque objects using a light microscope?

Tasks

Learn the rules of using a microscope.

Using additional sources of information, find out what details of the structure of living organisms can be seen with the most modern microscopes.

Do you know that…

Light microscopes with two lenses were invented in the 16th century. In the 17th century Dutchman Antonie van Leeuwenhoek designed a more advanced microscope, providing magnification up to 270 times, and in the 20th century. An electron microscope was invented, magnifying images tens and hundreds of thousands of times.

§ 7. Cell structure

1. Why is the microscope you are working with called a light microscope?

2. What are the smallest grains that make up fruits and other plant organs called?

You can get acquainted with the structure of a cell using the example of a plant cell by examining a preparation of onion scale skin under a microscope. The sequence of drug preparation is shown in Figure 18.

The microslide shows elongated cells, tightly adjacent to one another (Fig. 19). Each cell has a dense shell With at times, which can only be distinguished at high magnification. The composition of plant cell walls includes a special substance - cellulose, giving them strength (Fig. 20).

Rice. 18. Preparation of onion skin scale preparation

Rice. 19. Cellular structure of onion skin

Under the cell membrane there is a thin film - membrane. It is easily permeable to some substances and impermeable to others. The semi-permeability of the membrane remains as long as the cell is alive. Thus, the membrane maintains the integrity of the cell, gives it shape, and the membrane regulates the flow of substances from the environment into the cell and from the cell into its environment.

Inside there is a colorless viscous substance - cytoplasm(from the Greek words “kitos” - vessel and “plasma” - formation). When strongly heated and frozen, it is destroyed, and then the cell dies.

Rice. 20. Structure of a plant cell

In the cytoplasm there is a small dense core, in which one can distinguish nucleolus. Using an electron microscope, it was found that the cell nucleus has a very complex structure. This is due to the fact that the nucleus regulates the vital processes of the cell and contains hereditary information about the body.

In almost all cells, especially in old ones, cavities are clearly visible - vacuoles(from the Latin word “vacuum” - empty), limited by a membrane. They're filled cell sap– water with sugars and other organic and inorganic substances dissolved in it. By cutting a ripe fruit or other juicy part of a plant, we damage the cells, and juice flows out of their vacuoles. Cell sap may contain coloring substances ( pigments), giving blue, purple, crimson color to petals and other parts of plants, as well as autumn leaves.

Preparation and examination of a preparation of onion scale skin under a microscope

1. Consider in Figure 18 the sequence of preparing the onion skin preparation.

2. Prepare the slide by wiping it thoroughly with gauze.

3. Use a pipette to place 1–2 drops of water onto the slide.

Using a dissecting needle, carefully remove a small piece of clear skin from the inside of the onion scale. Place a piece of peel in a drop of water and straighten it with the tip of a needle.

5. Cover the peel with a cover slip as shown in the picture.

6. Examine the prepared preparation at low magnification. Note which parts of the cell you see.

7. Stain the preparation with iodine solution. To do this, place a drop of iodine solution on a glass slide. Use filter paper on the other side to pull off excess solution.

8. Examine the colored preparation. What changes have occurred?

9. Examine the specimen at high magnification. Find on it a dark stripe surrounding the cell - the membrane; underneath it is a golden substance - the cytoplasm (it can occupy the entire cell or be located near the walls). The nucleus is clearly visible in the cytoplasm. Find the vacuole with cell sap (it differs from the cytoplasm in color).

10. Sketch 2-3 cells of onion skin. Label the membrane, cytoplasm, nucleus, vacuole with cell sap.

In the cytoplasm of a plant cell there are numerous small bodies - plastids. At high magnification they are clearly visible. In the cells of different organs the number of plastids is different.

In plants, plastids can be of different colors: green, yellow or orange and colorless. In the skin cells of onion scales, for example, plastids are colorless.

The color of certain parts of them depends on the color of plastids and on the coloring substances contained in the cell sap of various plants. Thus, the green color of leaves is determined by plastids called chloroplasts(from the Greek words “chloros” - greenish and “plastos” - fashioned, created) (Fig. 21). Chloroplasts contain green pigment chlorophyll(from the Greek words “chloros” - greenish and “phyllon” - leaf).

Rice. 21. Chloroplasts in leaf cells

Plastids in Elodea leaf cells

1. Prepare a preparation of Elodea leaf cells. To do this, separate the leaf from the stem, place it in a drop of water on a glass slide and cover with a coverslip.

2. Examine the preparation under a microscope. Find chloroplasts in the cells.

3. Draw the structure of an Elodea leaf cell.

Rice. 22. Shapes of plant cells

The color, shape and size of cells in different plant organs are very diverse (Fig. 22).

The number of vacuoles, plastids in cells, the thickness of the cell membrane, the location of the internal components of the cell varies greatly and depends on what function the cell performs in the plant body.

ENVIRONMENT, CYTOPLASMA, NUCLEUS, NUCLEOLUS, VACUOLES, Plastids, CHLOROPLASTS, PIGMENTS, CHLOROPHYLL

Questions

1. How to prepare onion skin preparation?

2. What structure does a cell have?

3. Where is the cell sap and what does it contain?

4. What color can coloring substances found in cell sap and plastids give to different parts of plants?

Tasks

Prepare cell preparations of tomato, rowan, and rose hip fruits. To do this, transfer a particle of pulp into a drop of water on a glass slide with a needle. Use the tip of a needle to separate the pulp into cells and cover with a coverslip. Compare the cells of the fruit pulp with the skin cells of the onion scales. Note the color of the plastids.

Sketch what you see. What are the similarities and differences between onion skin cells and fruit cells?

Do you know that…

The existence of cells was discovered by the Englishman Robert Hooke in 1665. Examining a thin section of cork (cork oak bark) through a microscope he constructed, he counted up to 125 million pores, or cells, in one square inch (2.5 cm) (Fig. 23). R. Hooke discovered the same cells in the core of elderberry and the stems of various plants. He called them cells. Thus began the study of the cellular structure of plants, but it was not easy. The cell nucleus was discovered only in 1831, and the cytoplasm in 1846.

Rice. 23. R. Hooke’s microscope and the view of a section of cork oak bark obtained with its help

Quests for the curious

You can prepare the “historical” preparation yourself. To do this, place a thin section of a light-colored cork in alcohol. After a few minutes, start adding water drop by drop to remove air from the cells - “cells”, which darkens the drug. Then examine the section under a microscope. You will see the same thing as R. Hooke in the 17th century.

§ 8. Chemical composition of the cell

1. What is a chemical element?

2. What organic substances do you know?

3. Which substances are called simple and which are complex?

All cells of living organisms consist of the same chemical elements that are part of inanimate objects. But the distribution of these elements in cells is extremely uneven. Thus, about 98% of the mass of any cell is made up of four elements: carbon, hydrogen, oxygen and nitrogen. The relative content of these chemical elements in living matter is much higher than, for example, in the earth's crust.

About 2% of a cell's mass is made up of the following eight elements: potassium, sodium, calcium, chlorine, magnesium, iron, phosphorus and sulfur. Other chemical elements (for example, zinc, iodine) are contained in very small quantities.

Chemical elements combine with each other to form inorganic And organic substances (see table).

Inorganic substances of the cell- This water And mineral salts. Most of all the cell contains water (from 40 to 95% of its total mass). Water gives the cell elasticity, determines its shape, and participates in metabolism.

The higher the metabolic rate in a particular cell, the more water it contains.

Chemical composition of the cell, %

Approximately 1–1.5% of the total cell mass is made up of mineral salts, in particular salts of calcium, potassium, phosphorus, etc. Compounds of nitrogen, phosphorus, calcium and other inorganic substances are used for the synthesis of organic molecules (proteins, nucleic acids, etc.). With a lack of minerals, the most important vital processes of the cell are disrupted.

Organic matter are found in all living organisms. These include carbohydrates, proteins, fats, nucleic acids and other substances.

Carbohydrates are an important group of organic substances, as a result of the breakdown of which cells receive the energy necessary for their life. Carbohydrates are part of cell membranes, giving them strength. Storage substances in cells - starch and sugars - are also classified as carbohydrates.

Proteins play a vital role in cell life. They are part of various cellular structures, regulate vital processes and can also be stored in cells.

Fats are deposited in cells. When fats are broken down, the energy needed by living organisms is also released.

Nucleic acids play a leading role in preserving hereditary information and transmitting it to descendants.

A cell is a “miniature natural laboratory” in which various chemical compounds are synthesized and undergo changes.

INORGANIC SUBSTANCES. ORGANIC SUBSTANCES: CARBOHYDRATES, PROTEINS, FATS, NUCLEIC ACIDS

Questions

1. What chemical elements are most abundant in a cell?

2. What role does water play in the cell?

3. What substances are classified as organic?

4. What is the importance of organic substances in a cell?

Think

Why is the cell compared to a “miniature natural laboratory”?

§ 9. Vital activity of the cell, its division and growth

1. What are chloroplasts?

2. In what part of the cell are they located?

Life processes in the cell. In the cells of an elodea leaf, under a microscope, you can see that green plastids (chloroplasts) smoothly move along with the cytoplasm in one direction along the cell membrane. By their movement one can judge the movement of the cytoplasm. This movement is constant, but sometimes difficult to detect.

Observation of cytoplasmic movement

You can observe the movement of the cytoplasm by preparing micropreparations of leaves of Elodea, Vallisneria, root hairs of watercolor, hairs of staminate filaments of Tradescantia virginiana.

1. Using the knowledge and skills acquired in previous lessons, prepare microslides.

2. Examine them under a microscope and note the movement of the cytoplasm.

3. Draw the cells, using arrows to show the direction of movement of the cytoplasm.

The movement of the cytoplasm promotes the movement of nutrients and air within the cells. The more active the vital activity of the cell, the greater the speed of movement of the cytoplasm.

The cytoplasm of one living cell is usually not isolated from the cytoplasm of other living cells located nearby. Threads of cytoplasm connect neighboring cells, passing through pores in the cell membranes (Fig. 24).

Between the membranes of neighboring cells there is a special intercellular substance. If the intercellular substance is destroyed, the cells separate. This happens when potato tubers are boiled. In ripe fruits of watermelons and tomatoes, crumbly apples, the cells are also easily separated.

Often, living, growing cells of all plant organs change shape. Their shells are rounded and in some places move away from each other. In these areas, the intercellular substance is destroyed. arise intercellular spaces filled with air.

Rice. 24. Interaction of neighboring cells

Living cells breathe, eat, grow and reproduce. Substances necessary for the functioning of cells enter them through the cell membrane in the form of solutions from other cells and their intercellular spaces. The plant receives these substances from the air and soil.

How a cell divides. Cells of some parts of plants are capable of division, due to which their number increases. As a result of cell division and growth, plants grow.

Cell division is preceded by division of its nucleus (Fig. 25). Before cell division, the nucleus enlarges, and bodies, usually cylindrical in shape, become clearly visible in it - chromosomes(from the Greek words “chroma” - color and “soma” - body). They transmit hereditary characteristics from cell to cell.

As a result of a complex process, each chromosome seems to copy itself. Two identical parts are formed. During division, parts of the chromosome move to different poles of the cell. In the nuclei of each of the two new cells there are as many of them as there were in the mother cell. All contents are also evenly distributed between the two new cells.

Rice. 25. Cell division

Rice. 26. Cell growth

The nucleus of a young cell is located in the center. An old cell usually has one large vacuole, so the cytoplasm in which the nucleus is located is adjacent to the cell membrane, while young cells contain many small vacuoles (Fig. 26). Young cells, unlike old ones, are able to divide.

INTERCELLULARS. INTERCELLULAR SUBSTANCE. CYTOPLASM MOVEMENT. CHROMOSOMES

Questions

1. How can you observe the movement of the cytoplasm?

2. What is the significance of the movement of cytoplasm in cells for a plant?

3. What are all plant organs made of?

4. Why don't the cells that make up the plant separate?

5. How do substances enter a living cell?

6. How does cell division occur?

7. What explains the growth of plant organs?

8. In what part of the cell are the chromosomes located?

9. What role do chromosomes play?

10. How does a young cell differ from an old one?

Think

Why do cells have a constant number of chromosomes?

A task for the curious

Study the effect of temperature on the intensity of cytoplasmic movement. As a rule, it is most intense at a temperature of 37 °C, but already at temperatures above 40–42 °C it stops.

Do you know that…

The process of cell division was discovered by the famous German scientist Rudolf Virchow. In 1858, he proved that all cells are formed from other cells by division. At that time, this was an outstanding discovery, since it was previously believed that new cells arise from the intercellular substance.

One leaf of an apple tree consists of approximately 50 million cells of different types. Flowering plants have about 80 different types of cells.

In all organisms belonging to the same species, the number of chromosomes in cells is the same: in the house fly - 12, in Drosophila - 8, in corn - 20, in strawberries - 56, in crayfish - 116, in humans - 46, in chimpanzees , cockroach and pepper - 48. As you can see, the number of chromosomes does not depend on the level of organization.

Attention! This is an introductory fragment of the book.

If you liked the beginning of the book, then the full version can be purchased from our partner - the distributor of legal content, LitRes LLC.

Natalya Velichkina

Target: Give children an idea of ​​what water changes its color when various substances are dissolved in it. Activate children's vocabulary; develop the ability to make simple conclusions. Consolidate knowledge about color. Foster a positive attitude towards experimental research activities.

Equipment: Different colors colors, brushes, jars of clear water, pebbles.

Move: A drop brings colors to children.

droplet: Hello guys. Guys, look what I brought you today.

Children: Paints.

droplet: Why do we need paints?

Children: To draw.

droplet: Do you want to play with colors?

Children: Yes.

droplet: Today we will experiment with paints and water. To start the experiment, you need to put on aprons. Guys, why do you need to wear aprons?

Children: To avoid getting dirty.

droplet: That's right, guys. Look, there are glasses on the tables. What's in the cups?

Children: Water.

droplet: Which water has color?

Children: The water is clear.

droplet: How can you color water?

Children: Add paint.

droplet: Let's take some brushes and use them to place the paint into the water.

Children pick up paint with a brush, dip the brush into water, stir and watch how water changes color.

droplet: Vanya, please tell me which one color stand by the water in your glass?

Pauline: Yellow.

droplet: And what about Matvey? the water became the color?

Kirill: Blue.

droplet: Well done boys. Now let's play a game "Let's hide the pebbles".

A game "Let's hide the pebbles"- children throw pebbles into cups of colored water.

droplet: Where are the pebbles?

Children: In water.

droplet: Why are they not visible?

Children: The pebble is not visible because water is colored.

droplet: Well done boys. Let's do it conclusion: water takes on color substance dissolved in it; objects are not visible in colored water.

droplet: Well done, now it’s time for me to go home. See you later.

Application.

Publications on the topic:

Goal: To develop cognitive interest, thinking and physical qualities. Develop a caring attitude towards nature. Equipment: masks, rope.

New Year is a fairy tale that adults and children believe in. Preparing for the New Year is a time of magic and creativity. Parents, teachers, kids with passion.

Winter has come, snow has covered the ground with a fluffy blanket. Children enjoy sledding, ice-skating, skiing, and skating. And each of them is looking forward.

Lesson notes on Social and Communicative Development “Mommy, Mommy, how I love you!” second junior group. Progress of the lesson: The teacher rings the bell with the words: Naughty bell, you form the children into a circle. The guys gathered in a circle on the left.

Project “All the kids need to know how to walk down the street” (second junior group) Completed by: Barsukova S. N. Conducted by: Barsukova S. N. Type of project: short-term (week). Project type: educational and gaming. Participants.

Lesson type - combined

Methods: partially search, problem presentation, reproductive, explanatory and illustrative.

Target:

Students’ awareness of the significance of all the issues discussed, the ability to build their relationships with nature and society based on respect for life, for all living things as a unique and invaluable part of the biosphere;

Tasks:

Educational: show the multiplicity of factors acting on organisms in nature, the relativity of the concept of “harmful and beneficial factors”, the diversity of life on planet Earth and the adaptation options of living beings to the entire range of environmental conditions.

Educational: develop communication skills, the ability to independently obtain knowledge and stimulate one’s cognitive activity; ability to analyze information, highlight the main thing in the material being studied.

Educational:

Formation of an ecological culture based on recognition of the value of life in all its manifestations and the need for a responsible, careful attitude towards the environment.

Forming an understanding of the value of a healthy and safe lifestyle

Personal:

nurturing Russian civic identity: patriotism, love and respect for the Fatherland, a sense of pride in one’s Motherland;

Formation of a responsible attitude towards learning;

3) Formation of a holistic worldview that corresponds to the modern level of development of science and social practice.

Cognitive: ability to work with various sources of information, transform it from one form to another, compare and analyze information, draw conclusions, prepare messages and presentations.

Regulatory: the ability to organize independent completion of tasks, evaluate the correctness of work, and reflect on one’s activities.

Communicative: Formation of communicative competence in communication and cooperation with peers, seniors and juniors in the process of educational, socially useful, educational and research, creative and other types of activities.

Planned results

Subject: know the concepts of “habitat”, “ecology”, “ecological factors”, their influence on living organisms, “connections between living and non-living things”;. Be able to define the concept of “biotic factors”; characterize biotic factors, give examples.

Personal: make judgments, search and select information; analyze connections, compare, find an answer to a problematic question

Metasubject:.

The ability to independently plan ways to achieve goals, including alternative ones, to consciously choose the most effective ways to solve educational and cognitive problems.

Formation of semantic reading skills.

Form of organization of educational activities - individual, group

Teaching methods: visual-illustrative, explanatory-illustrative, partially search-based, independent work with additional literature and a textbook, with COR.

Techniques: analysis, synthesis, inference, translation of information from one type to another, generalization.

Practical work 4.

MANUFACTURING A MICROPREPARATION OF TOMATO FRUIT (WATERmelon) PULP, STUDYING IT USING A magnifying glass

Objectives: consider the general appearance of a plant cell; learn to depict the examined microslide, continue to develop the skill of independently making microspecimens.

Equipment: magnifying glass, soft cloth, slide, cover glass, glass of water, pipette, filter paper, dissecting needle, piece of watermelon or tomato.

Progress

Cut the tomato(or watermelon), using a dissecting needle, take a piece of pulp and place it on a glass slide, drop a drop of water with a pipette. Mash the pulp until you obtain a homogeneous paste. Cover the preparation with a cover glass. Remove excess water using filter paper

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.

A living watermelon pulp cell under a microscope

WATERMELON under a microscope: macro photography (magnification 10X video)

Appleundermicroscope

Manufacturingmicroslide

Resources:

I.N. Ponomareva, O.A. Kornilov, V.S. Kuchmenko Biology: 6th grade: textbook for students of general education institutions

Serebryakova T.I.., Elenevsky A. G., Gulenkova M. A. et al. Biology. Plants, Bacteria, Fungi, Lichens. Trial textbook for grades 6-7 of secondary school

N.V. Preobrazhenskaya Biology workbook for the textbook by V. Pasechnik “Biology 6th grade. Bacteria, fungi, plants"

V.V. Pasechnik. Manual for teachers of general education institutions Biology lessons. 5-6 grades

Kalinina A.A. Lesson developments in biology grade 6

Vakhrushev A.A., Rodygina O.A., Lovyagin S.N. Verification and control work for

textbook "Biology", 6th grade

Presentation hosting

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.