Municipal budgetary educational institution

Velizh secondary school №2

Excursion

"Autumn phenomena in plant life"

6th grade

Performed:

Kudryashova Ekaterina Vyacheslavovna,

biology and chemistry teacher

Goals:

educational - to develop in students the concepts of trees, shrubs and herbaceous plants, the duration of their life, the adaptability of plants to environmental conditions; autumn leaf color, leaf fall, seed distribution, features of the external structure of flowering plants in different habitats, preparation of plants for winter; to form a general educational skill in the preparation of a written report on the excursion.

developing - develop curiosity, cognitive interest in seasonal changes in nature and Creative skills children.

educational - to develop a dialectical-materialistic worldview, revealing the reasons for the onset of autumn phenomena in the life of plants by establishing links between them and changes in environment; to form in students an aesthetic perception of nature.

Equipment:

leaf herbarization folder;

cards - tasks;

didactic material depicting trees and shrubs;

plastic bags for collecting seeds and fruits;

magnifying glass, ruler, notebook, pencils.

Teaching methods:

observation;

conversation;

story;

object recognition.

Plan:

I. Opening speech of the teacher.

II. Independent work card students.

III. Tour results.

IV. Homework.

Conducting an excursion.

I . Teacher: Guys, here we are with you and on the spot. Look around, what time of year is it?

Students: Autumn

Teacher: Correctly! Isn't it a wonderful time of the year. How many poems have been written about him, how many pictures have been drawn, you can’t even count. Listen to I. Bunin's poem "Falling Leaves":

“Forest, like a painted tower,

Purple, gold, crimson,

Merry motley wall

It stands over a bright meadow.

Birches with yellow carving

Shine in blue azure,

Like towers, Christmas trees darken,

And between the maples they turn blue

Here and there in the foliage through

Clearances in the sky, that windows ... "

I reveal for children the secrets of the amazing things of nature.

Teacher: Guys, I asked you to find some poems, stories, proverbs, riddles on the theme "Autumn". Let's check what you have prepared.

Student:

Sad time! Oh charm!

Your farewell beauty is pleasant to me -

I love the magnificent nature of wilting,

Forests clad in crimson and gold,

In their canopy of the wind noise and fresh breath,

And the heavens are covered with mist,

And a rare ray of sun, and the first frosts,

And distant gray winter threats.

(A.S. Pushkin)

Teacher: Well done! Have any of you prepared more poems?

Student 1: Poems about autumn

Already the sky was breathing in autumn,

The sun shone less

The day was getting shorter

Forests mysterious canopy

With a sad noise she was naked,

Fog fell on the fields

Noisy geese caravan

Stretched to the south: approaching

Pretty boring time;

November was already at the yard.

(A.S. Pushkin)

Student 2: Proverbs about autumn:

In autumn, cattle grow fat, and people become kinder.

Autumn is boastful, spring is fair.

Autumn will order, and spring will say its own.

Autumn is a reserve, winter is a pickle.

Autumn is harvest time.

Autumn - eight weather changes.

Buzzes like a thin fly in autumn.

In autumn, even a crow has a pile of bread.

Autumn will come, he will ask for everything.

Do not count your chickens before they are hatched.

In autumn, and at the sparrow's feast.

In autumn, even the sparrow is rich.

Autumn brings bad weather.

Student 3: Riddles about autumn:

I bring the harvest
I sow the fields again
Sending birds to the south
I undress the trees
But I do not touch pines and fir-trees.
I - ...
(Autumn)

Green, not a meadow,

Bela, not snow,

Curly but no hair.

(Birch)

Student 4:

Sits - turns green,

Flies - turns yellow,

It will fall - it will turn black.

(Sheet)

Cheerful in the spring

It's cold in summer

Feeds in autumn

Warms in winter.

(Forest)

Teacher: Well done boys! You have prepared very well.

Guys, what do you think, why do not some people like autumn?

Student: in autumn, the leaves fall, the plants fade, everything turns yellow and it rains.

Teacher: Correctly. Guys, look around, what do you see?

Student: papers, bottles, broken glass.

Teacher: all this garbage is not needed by nature. Why do you think?

Student: this garbage is not needed by nature, because it decomposes for a long time and pollutes the environment.

Teacher: Right. For example, plastic bags take about 100 years to decompose. Guys, if we came to the forest for a picnic, what should we do when we leave?

Student: We must take all the waste with us, and bury what easily decomposes.

Teacher: All right. Today we came here to find out why plants shed their leaves, why leaves turn yellow and much more. So, what changes have occurred with the change of summer to autumn?

Students: the day has decreased, the air temperature has decreased, the humidity has increased, a large amount of precipitation falls.

Teacher: Everything is correct. What changes have taken place in plants?

Students: The grass has darkened, the leaves of trees and shrubs have turned yellow, the leaves are falling, some plants have faded, and some have already appeared seeds.

Teacher: Right.

II . Teacher: Guys, after the tour we will have to answer the questions: Why do seasonal changes in weather conditions affect the life of plants in the fall and how do plants adapt to changes in conditions external environment And how do they prepare for winter?

In order to answer all these questions, we need to complete a number of tasks. For work, we need to divide into 5 groups of 4 people each and each group receives its individual task on a card.

Assignments involve the performance of two types of work:

First view The work is aimed mainly at familiarizing students with the diversity of species of woody plants, identifying signs of plant adaptation to autumn conditions.

Second view work is aimed at the formation of aesthetic values ​​of nature.

Before completing the assignments, I conduct a briefing.

I give an example of 2 cards (there were 5 in total).

Card 1

To study the process of leaf fall.

1. Note the changes in the life of trees, shrubs, herbs. What was the color of most plants, and which plants remained green until the frost.

2. Mark in the table the types of plants and the timing of their leaf fall: partially dropped, completely freed from foliage, left for the winter (+).

leaf fall

Plant

Partially dropped

Completely dropped

Left for the winter

3. Using a magnifying glass, examine the base of the petiole of the fallen leaf and find the layer of tissue that contributed to its separation.

4. Collect leaves of various colors and make a herbarium out of them with signatures of plant names.

5. Consider the color of the leaves of various trees and shrubs and enter the data in the table.

leaf coloring

plant name

leaf coloring

6. Is the duration of leaf fall the same for different types trees and shrubs?

7. Write a short story on the topic: "Autumn."

Card 2

Explore the variety of fruits.

1. Collect fruits that are spread by the wind (ash, maple, linden, birch).

2. Collect fruits that are distributed by birds (mountain ash, viburnum, elderberry).

3. Collect fruits that are spread by man (string, gravel, plantain, chamomile, burdock).

4. Collect fruits that spread by self-spreading (acacia).

5.Fill in the table.

plant name

fruit type

Features of the structure of the fetus

Distribution methods

Oak

acorn

Brown, surrounded by a plush.

With the help of animals and humans

6. Why do plants form hairs and wings on fruits? What is it connected with?

7. Make 2 syncwines on the theme: "Autumn".

1. 1. When summing up in a generalizing conversation, I find out how students learned the material on this topic.

So, guys, come up to me and answer the question: When does the calendar and astronomical autumn begin?

Students: calendar autumn begins on September 1, and astronomical - after September 23.

Teacher: And botanical autumn always comes somehow unexpectedly with the appearance of massive yellowing of the foliage of birch and linden. However, real autumn comes not even when all the leaves on the trees turn yellow, but from the time when the leaf fall begins. Why do you guys think this phenomenon is very important for plants?

Students: It is during this period that the plant prepares for an unfavorable period - winter. It is with the fall of the leaves that evaporation decreases.

Teacher: What would happen if the leaves didn't fall?

Student: With the preservation of foliage, evaporation would continue, the roots could not compensate for the loss of moisture due to freezing of the soil, and this would lead to the death of the plant. Dropping leaves protects the plant from mechanical damage, because. Under the weight of snow on a wide leaf blade, the branches would break. Together with the leaves, the plant removes harmful substances, which by autumn from trunks and stems turn into leaves.

Teacher: Everything is correct. Tell me, guys, is the duration of leaf fall the same for different types of trees?

Students: No, she's different.

Teacher: But what about leaf fall?

Students: By autumn, special small cells resembling a cork are formed at the base of the leaf petiole - this is a separating layer.

Teacher: What is the name of the place on the stem where the leaf was attached?

Student: This place is called a leaf scar.

Teacher: during the period of leaf fall, the leaves change their color to yellow, red, purple, what explains this variety of colors?

Students: This is due to the fact that in addition to chlorophyll, there are other coloring substances in the leaves. But in spring, the green pigment covers them and prevents them from appearing. In autumn, chlorophyll is destroyed and another substance begins to predominate - anthocyanin, from which the leaves turn red or purple.

Teacher: Well done guys, you're right. Why do you think coniferous trees do not shed needles for the winter?

Student: Pine and spruce are drought-resistant plants, the evaporating surface of their needles is very small and they are covered with a wax coating, which almost does not let moisture through.

Teacher: At the end of the conversation, I note smart, observant, organized guys.

So, guys, today we did a great job with you, we watched how plants prepare for winter, leaf fall.

I conclude by giving the material integrity.

IV . I remind you of the deadlines for a written report. Each group
schoolchildren submit a completed report on the excursion, in which, in addition to the results of observations, they record personal impressions based on sensory perception of the surrounding nature.

Based on the results of the excursion, I conduct a generalizing lesson. For this lesson in the biology classroom, I mount an exhibition of the most successful creative works of students: essays - miniatures, poems of my own composition, drawings, collections of fruits and seeds, herbarium sheets, crafts made from natural material.

Children express their admiration for natural phenomena, their feelings, love in drawing, in writing poetry, syncwines, crossword puzzles, essays, stories.

Reports are reviewed and evaluated by:

In a generalizing lesson, we summarize the tour of the two types of work provided for in the cards. The guys read their answers to questions, show drawings, read poetry, exchange opinions, and lead discussions.

The experience of holding such discussions shows the role and importance of excursions: the guys become more active, more interested in the material being studied and discussed, they share their observations and impressions with pleasure. Observing the picturesque corners of nature, schoolchildren learn to understand beauty, they develop a love for Russian nature.

Excursions provide good material for the education of aesthetic feelings, a materialistic worldview, dialectical understanding, ecological ties, the unity and integrity of natural complexes.

Sources

Pasechnik V.V. Biology, mushrooms, plants. Grade 6: textbook. for educational institutions. - M .: Bustard, 2010.

Internet resources:

1. A.S. Pushkin "Already the sky was breathing in autumn"

2. A.S. Pushkin "The Sad Time"

3. I. Bunin "Leaf fall"

4. proverbs about autumn

5 . riddles about autumn

The life span of green leaves developed on shoots varies from plant species to 2-3 weeks to 20 years or more. In general, it should be noted that the leaves perennials compared to the stem and root, they have the shortest life span. This is apparently due to the fact that the leaf tissues, having formed, are no longer renewed, and on the other hand, the leaves function very actively during their relatively short life.

Distinguish plant types deciduous and evergreen. The former are characterized by the fact that annually for a certain period they are in a leafless state, and this period usually coincides with unfavorable environmental conditions. For example, most of our trees and shrubs do not have leaves in winter.

Evergreens are characterized by having green leaves throughout the year. But this does not mean that their leaf is preserved and functions forever, throughout the life of the individual. Evergreens also have leaf fall, but older leaves fall from the plant and the leaves that formed at a later date are always preserved.

Tropical rainforests are characterized by evergreens, although there are also plants with leaves that last less than a year. But during this period of time, the buds repeatedly open and give rise to new leafy shoots. In tropical forests, plants with leaves that live for several years are also common. There are plants that, although for a short period of time in the year, may be in a leafless state.

In evergreens near Moscow - spruce and pine - the leaves persist for 5-7 (for spruce) and 2-4 (for pine) years. The life span of spruce needles is longer in plants growing in the Kola Peninsula and the Subpolar Urals, where it reaches 12-16, and in some cases 18 (22) years. The needles of the Tien Shan spruce (Picea scgenkiana F. et. M.) in the Zailiysky Alatau, where leaves of 26-28 years of age, were found for a long time. (According to I. G. Serebryakov (1952)).

Leaf fall is a biological process, due to the development of the plant organism and its vital activity. Leaf fall is preceded by leaf aging: the intensity of vital processes occurring in its cells (photosynthesis, respiration) decreases, the content of ribonucleic acid, nitrogen and potassium compounds decreases. Hydrolysis prevails over the synthesis of substances; end products of decay accumulate in cells (for example, calcium oxalate crystals). The most valuable mineral and plastic compounds leave the leaves. Their outflow usually coincides either with the formation and growth of new organs, or with the deposition of reserve substances in ready-made storage tissues. In experiments, it was possible to extend the life of the leaves by removing buds or other formations on the plant, where plastic and mineral substances from the leaves can enter. The transfer of substances to places of their reuse is considered as one of the causes of aging and leaf fall.

Thus, the lifespan of a leaf is determined by the processes of growth and development of the plant organism as a whole.

In most trees and shrubs, during the period of leaf fall, the leaves change color and become yellow or crimson. Their yellow color is due to plastid pigments (carotene and xanthophyll) and cell sap (flavones).

The reddish-purple color of the leaves is provided by the accumulation of anthocyanin pigment in the cell sap, which changes its color depending on the pH of the medium. In an alkaline environment, the anthocyanin takes on a bluish-blue color, and in an acidic environment, it becomes pink-purple. In some plants (alder, lilac), the leaves remain green until they die.

In addition to the biochemical transformations that occur in the leaves before they fall, anatomical changes are also observed at the base of the leaf. Perpendicular to the longitudinal axis of the petiole, cells of the separating layer are laid near the stem. The intercellular substance connecting these cells becomes mucilaginous, and the cells separate from each other. At the place of separation of the leaf from the side of the stem, layers of cells are formed by this time, the membranes of which are corked. The resulting layer of cork protects the internal tissues of the stem in place of the detached leaf.

After the formation of a separating layer and the disruption of the connection between the cells, the leaf continues to remain on the tree for some time due to the conductive bundles connecting the leaf to the stem. But there comes a moment of violation of this connection, and the leaves fall.

Back forward

Attention! The slide preview is for informational purposes only and may not represent the full extent of the presentation. If you are interested in this work, please download the full version.

Lesson Objectives:

• expand and clarify children's ideas about autumn changes in plant life;
• provide conditions for the development of students' speech, the development of voluntary attention;
• create conditions for the emotional perception of autumn nature.

Tasks

subject:

1) to form children's ideas about autumn changes in plant life.

2) to show the connection of autumn changes in the plant world with the signs of autumn in inanimate nature;

metasubject:

3) develop the ability to analyze, compare and find the necessary information in the text;

4) develop the ability to establish causal relationships, generalize and systematize observations, draw conclusions;

5) develop the ability to work with a diagram, use a dictionary;

personal:

6) develop an emotional perception of autumn nature;

7) cultivate aesthetic feelings, respect for nature.

8) to form the ability to work in a group

Equipment:

• Personal computer, interactive kit
• Textbook "The world around" Grade 3, O.T. Poglazova, V.D. Shilin
• Workbook No. 1, 3rd grade, O.T. Poglazova
• Handout (cards with assignments for group work, green and yellow sheets of colored paper, strips with pieces for the test)

During the classes

1. Organizational moment.

Hello, have a seat.

The bell rang and stopped, the lesson began.

2. Emotional mood.

Video "Autumn in the forest" (Slide number 2)

In what mood did you watch the movie? (Good, happy)

What creates a good mood? (Very bright colors, good music)

In a good mood, we walk through the autumn forest. Slide #3

Forest, like a painted tower,
Lilac, gold, crimson
Cheerful, colorful wall
It stands over a bright meadow.
(I. Bunin)

In his wonderful poems, I. Bunin called the forest a painted tower. And who painted it? (Autumn)

3. Setting the topic of the lesson.

Who guessed what will be discussed at the lesson today? (About autumn in the forest, about autumn leaves)

That's right, the topic of our lesson is "Autumn changes in plant life."

Today we will talk about how the life of plants has changed with the advent of autumn. .(Slide number 4)

4. Actualization of knowledge.

How did you know that autumn had come in the forest? (The color of the leaves has changed)

The Wise Owl has prepared a task for you. Divide the pictures into groups and answer the questions: -What autumn is depicted in each group? Why? (Slide number 5)

What caused autumn to change the color of the leaves? Name the reasons.

(Slide #6- sun, thermometer, rain)

1. The sun is lower - little light and heat, days become shorter than nights

2. Lowering the air and water temperature, the appearance of frost on the ground. And then the first frost.

3. Precipitation change: fogs, heavy rains, first snow

Correctly. It is these reasons that made autumn change the life of plants.

5. Learning new things.

1) Changing the color of leaves is a very beautiful phenomenon in plant life. Let's see how this happens?

(Slide number 7) In summer, all trees have the same color - green. Chlorophyll gives the green color to the leaves. Of course, green color has different shades, but it seems that they were painted with the same brush. But in the fall, the same leaves acquire a different color. Where do these colors come from?

Why does the color of leaves change in autumn? (Slide number 8)

Textbook: p.46, 1 paragraph (children's answers)

(Slide number 9) In summer, the day is long. Chlorophyll has time to break down and regenerate. Therefore, the leaves are always green. In autumn, the days are short, there is little light, and chlorophyll does not have time to recover. Other dyes become brighter.

And what substances affect the color of the leaves? What else affects the brightness of colors?

Slides number 10-16 (additional information - teacher's story)

Slide #10 There is a substance called xanthophyll in the leaves, which makes the leaf yellow.

The yellow pigments are quite persistent, and in autumn the leaves of many plants turn yellow. However, the leaves of some trees do not have yellow dyes. Therefore, in autumn, when the activity of the leaf stops with a decrease in temperature, crimson, orange and purple pigments appear.

Slide number 11 Carotene gives the leaves an orange tint.

Slide #12 There is also anthocyanin, which gives sugar maple and red oak their vibrant red hues.

In addition, the outflow of organic substances from the leaves decreases in autumn, and various substances are formed in them that change the color of the leaves.

Slide number 13 The brightness and durability of color largely depend on the weather. Dry sunny autumn gives us not only a good mood, but also richly colored leaves.

Slide number 14 The age of the tree also affects the brightness of autumn tones. The younger it is, the fresher its leaves, the stronger they hold on the branches.

Slide number 15 Favors for bright outfits and warm, moderately humid autumn.

Slide No. 16 On the contrary, in rainy, cloudy autumn, the change in leaf color is slower. In the cold and rain, the colors of the forest are not so bright and quickly disappear.

And now we repeat the reasons for changing the color of the leaves

Slide number 17 We call the sequence of causes and consequences of changes:

• Decreased daylight hours
• Chlorophyll fails to recover
• Leaf color changes

Slide #18 Fizminutka for eyes "Autumn"

2) Slide number 19. Work in a printed notebook. Pupils perform task No. 7 - a crossword puzzle (spruce, cherry, apricot, apple tree, dog rose, mountain ash, oak).

Name and write the names of plants.

Name the keyword (leaf fall)

What is leaf fall? (children's answers)

Plants prepare for leaf fall in advance. First, the color of the leaves changes. But not all trees and shrubs do this. Leaves of lilac, alder fall green. Half of the aspen leaves will fall from the tree while the remaining leaves turn purple

Slide number 20. Why do leaves fall ?

The answer is in the textbook p.46-47.

(For reference. Tree roots suck up water from the soil. And through the leaves, water evaporates from the plant. As soon as the air temperature drops slightly, the absorption slows down, and the evaporation proceeds at about the same speed. The tree begins to lose more moisture than it receives. If this continues for a long time, then the tree will die from dehydration - it will dry out. To prevent this from happening, the tree begins to defend itself from the very beginning of the cold snap. It allocates special cells that go to the petioles of the leaves, fill their bases. A dense separating tissue is formed, which stops the access of moisture to the sheet. The leaf is no longer connected to the tree, it is dying. The tree needs this - it no longer values ​​the leaves, they even interfere with it. And fallen leaves will still help him to keep the roots of the tree in winter frosts, help him survive the winter.)

We name the sequence of causes and consequences of changes:

1. Lowering the temperature

2. Slowing down the movement of juices

3. Cork layer

4. Leaf fall

3) Slide #21- Why are the leaves falling?

Leaf fall (cause) - reduced evaporation saves from drought (consequence)

Getting rid of excess mineral salts (consequence)

4) - Return to the crossword puzzle. Which plant would you mark as superfluous? (Spruce)

Why? (Leaf fall in deciduous trees, but conifers do not have it.)

- Why do coniferous trees not fall leaves?

The answer to this question is in the textbook: p.47,2 paragraph.

Slide number 22 We name the answers:

1. Wax coating of needles saves from “winter drought”

2. Substances unnecessary for the tree accumulate slowly, the change of needles proceeds gradually

Larch is an exception in coniferous trees.

Why do larch needles fall off in autumn?

Slide number 23 Answer:

(Soft larch needles do not have a protective layer)

5) - What happens to herbaceous plants in autumn? Slide #24

Answer p.48. (Children's oral responses)

6. Physical Minute Slide #25

7. Test(graphic dictation) Plants in autumn Slide No. 26

001 - You have strips on your desk with short identical segments. I read the statement. Some of them are true, others are false. Where it is correct, you draw “”, where it is incorrect, we simply skip the segment.

1. Maple leaves are both red and yellow. +

2. Lilac leaves fall yellow. -

3. Aspen leaves constantly tremble, even if there is no wind. +

4. Willow has carved leaves. -

5. Rowan leaves turn red. +

6. Oak does not shed its leaves longer than others. +

7. Birch leaves are yellow. +

8. Ash is the last to turn yellow. -

9. From maple, like birch, they take sweet juice. +

10. All conifers stay green. -

Compare your answers with mine (appears in the presentation). Evaluate your work against the evaluation criteria.

Now let's find out the true statements. (The teacher reads the statements, the students name the correct answers, where the statements are incorrect.)

8. Group workSlide #27

Each group received a card, which is divided into three parts: picture, title, text. The text has already been typed. This is an excerpt from the story of autumn. Read it carefully and determine what period of autumn the writer spoke about. Select and paste the title of the text and a picture-illustration to it

1 group

Turgenev Ivan Sergeevich

The weather was inconsistent. Now it was raining lightly, then the sun was showing through the parted clouds. The grove either lit up all over, as if all of a sudden everything was smiling in it, then suddenly again everything around it turned slightly blue: the bright colors instantly went out and furtively began to sown and whisper the smallest rain through the forest.

The leaves rustled a little over my head; one could tell from their noise what season it was then. It was not the cheerful, laughing thrill of spring, not the soft whispering, not the long talk of summer, not the timid and cold babble of late autumn, but barely audible, drowsy chatter.

2 group

Skrebitsky Georgy Alekseevich

The Artist-Autumn took the brightest colors and went to the forest to paint her picture.

Birches and maples were covered by Autumn with lemon yellowness. And the leaves of the aspens were browned.
She presented the mighty oak with forged copper armor, and the lindens with a golden brocade headdress. There were pines and ate dark green in summer. And because of this, the forest in its motley autumn attire became even brighter, even more elegant.

3 group

Paustovsky Konstantin Georgievich

Often in the autumn I would closely watch the falling leaves to catch that split second when the leaf separates from the branch and begins to fall to the ground, but I did not succeed for a long time. I wanted to hear the rustle of falling leaves. If the leaves rustled, it was only on the ground, under the feet of a person.

One late evening, I saw a red leaf carefully and slowly detach from a maple branch, shuddered, stopped for a moment in the air and began to fall obliquely at my feet, slightly rustling and swaying. For the first time I heard the rustle of a falling leaf - an indistinct sound, like a child's whisper.

Speech by representatives of each group, showing pages with illustrations.

(example: slide #28)

9. Summary of the lesson Slide #29

What autumn changes in plant life did you learn about?

What periods of autumn were discussed in the lesson? (Early autumn, golden autumn, late autumn)

How do they differ?

10. Homework(slide number 30):

Creative (optional):

Compose short stories: “Autumn in the forest”, “Autumn time”, “Leaf fall in our city”;

Find poems about autumn;

Related drawing.

11. Reflection Slide №31

Birch without leaves on the board

You have leaves on the tables: green and yellow. Choose one.

• YELLOW: The lesson was interesting and useful to me.
• GREEN: Lesson passed with no benefit to me.

Now fasten your leaves to the birch.

Look how elegant our birch has become. Now we all see that the birch has met its golden autumn.

(Example: slide number 33)

12. In conclusion. Slide #32

Admiring the autumn nature, I wrote this poem:

Autumn.

Autumn took up colors again
And with might and main gilds the foliage.
Having stopped for the time of precipitation,
She is in a hurry to show her beauty.
beauty autumn trees,
The beauty of warm autumn days
So that on cold days by the stove
There was something to remember about them.
Knyshova M.E.
October 9, 2013

I wish you creative autumn inspiration!

THANK YOU FOR YOUR WORK! ( Slide #33)

RESOURCES USED:

1. Video “Autumn in the forest” Yankova Irina Viktorovna http://viki.rdf.ru/cat/vremena_goda/?page=8#list;
2. The idea of ​​a graphic dictation (in a test) was taken from the magazine “ Primary School” No. 6, 2013, p.25.
3. Template source: Shevlyak Irina Alekseevna, http://pedsovet.su/
4. Pictures http://images.yandex.ru/
5. Fizminutka "Autumn" Galkina I.A., http://pedsovet.su/load/244-1-0-2616
6. Fizminutka

Winter has come, and the leaves have not fallen on my apple trees. Why?
Galina RAZUMOVSKAYA, Novogrudok district

Sometimes it happens that the leaves remain on the branches even when frost occurs. They become black, lethargic, but do not fall off. Leaf fall is biologically required process for the development and growth of perennial plants, protecting them from moisture loss. Trees need water for overwintering. The evaporation process in some plants is slower, so the leaves do not fall until winter. This is facilitated essential oils or the presence of a slimy substance that fills special passages in the veins.

Why did your trees not fall leaves, if there is no apparent reason for this? At different varieties Apple tree leaves do not fall all at once. For example, at Antonovka, part of the greenery goes into the winter. It does not matter if she has all the shoots of a good degree of lignification, and the buds are formed and ready for wintering. We can talk about the pathology of the process when the shoots of the plant are weak, herbaceous, and the buds on them are differentiated. The leaves may be green, firmly attached to the branches. This is a typical sign of poor frost resistance.

The main reason for this phenomenon is overfeeding with nitrogen fertilizers. Sometimes this is observed with late top dressing of apple trees. Experts recommend not applying nitrogen fertilizers to the soil in the second half of summer, so that the foliage can completely fall off in the fall before wintering. If you are sure that they were applied correctly and the trees with the remaining leaves grew under equal conditions with other plants, then it can be assumed that these are non-regional varieties and their vegetation period is long. Thus, they simply did not have time to complete the development cycle.

An obvious reason for the delay in leaf fall can be improperly organized pruning in the summer, which provokes the growth of shoots, as well as excessively hot summers and humid autumns. Trees are oversaturated with moisture and do not have time to prepare for winter. At the same time, they continue to grow, and the outflow nutrients to the root system is delayed. As a result of the delay in leaf fall in autumn, apple trees enter the winter period weakened, their shoots are immature, and various bacteria and pathogens most often hide on the leaves. The consequences can be sunburn and frostbite of the tips of the branches in winter.

How to help an apple tree become more resistant to frost

Apply sniffing of leaves, that is, their removal. But do not confuse this technique with breaking. In no case should this be done, otherwise damage the shoots. Sniffing is carried out by holding the hand from the bottom up, as a result, dry and weak leaves are separated.

Before frost, you need to whitewash the trunks of the apple tree and the main branches.

Create a thermal cushion for the roots. After the first snow, trample it under the tree, sprinkle a mixture of sawdust and peat on top, and after the next snowfall, trample the snow again.

Prepared by Ivan ADAMENKO, agronomist

1 option
1. Write down the numbers corresponding to monocot plants:
No. 1 - fibrous root system
No. 2 - two cotyledons
No. 3 - one cotyledon
No. 4 - pericarp
No. 5 - seed peel
No. 6 - one germ layer
No. 7 - two germ layers
2. Define the concept: node, internode

I. petiolate
A. birch
B. maple
B. Currant
G. Aloe
D. Ryabina
E. Oats
G. Corn

I. Simple
A. Linden
B. Rosehip
B. Wheat
G. Clover
D. Oak
E. Acacia
5. The skin of the sheet is a tissue:
A. Pokrovnaya
B. Mechanical
B. Conductive
G. Spare
6. Light sheet, unlike shadow sheet:
A. Has a lighter color
B. Contains less chlorophyll
B. Has several layers of columnar cells
D. All statements are true
7. Write down the numbers corresponding to:
I - columnar tissue,
II - spongy tissue.
No. 1 - cells are adjacent to the upper skin
No. 2 - cells are rounded and irregular in shape
No. 3 - the cells are tightly adjacent to each other
No. 4 - elongated cells
No. 5 - intercellular spaces are filled with air
No. 6 - there are especially many chloroplasts in the cytoplasm of cells
8. Find a match. Write down the numbers indicating the modifications of the leaves characteristic of plants (letters).
A. barberry
B. cactus
B. Peas
G. sea buckthorn
D. Rosyanka
No. 1 - thorns
No. 2 - needles
No. 3 - spikes
No. 4 - mustache
No. 5 - hairs with sticky liquid

Option 2
1. Write down the numbers corresponding to dicot plants:
No. 1 - tap root system
No. 2 - two cotyledons
No. 3 - one cotyledon
No. 4 - pericarp
No. 5 - seed peel
No. 6 - one germ layer
No. 7 - two germ layers
2. Define the concept: shoot, leaf
3. Find a correspondence between the names of plants and the type of leaf arrangement they have:
I. Sedentary
A. birch
B. maple
B. Currant
G. Aloe
D. Ryabina
E. Oats
G. Corn
4. Find a match. Which plants have simple leaves and which ones have compound leaves.
I. Complex
A. Linden
B. Rosehip
B. Wheat
G. Clover
D. Oak
E. Acacia
5. Conductive leaf bundles consist of tissue cells:
A. Mechanical
B. Conductive
B. Mechanical and conductive
G. Reserve
6.Shadow sheet, unlike light sheet:
A. Has a darker color
B. Contains more chlorophyll
B. Has one layer of columnar cells
D. All statements are true
7. Write down the corresponding numbers indicating the characteristics of the leaves of plants in wet and dry places.
No. 1 - large leaves
No. 2 - small leaf size
No. 3 - dense pubescence of the leaf blade
No. 4 - a large number of stomata
No. 5 - wax coating on the outside of the sheet
No. 6 - a small number of stomata
Plants of wet places - No. ...
Plants of arid places - No. ...

8. Fill in the missing words.
1. Trailing cells, in the cytoplasm of which are ..., and the gap between them form ...
2. Penetrates into the leaf through the stomatal fissure ... and happens ...

Key
1 option
1. 1,3,6
3. A, B, C, D
4. A, B, D
5. A
6. G
7. I- 1,3,4,6 II- 2.5
8. A-3, B-2, V-4, G-1, D-5

Option 2
1. 1,2,5,7
3. G, E, F
4. B, D, E
5. In
6. G
7.I-1.4; II- 2,3,5,6
8. chloroplasts, stomatal apparatus;
carbon dioxide, photosynthesis