For germination of seeds, an optional condition is. Germination of seeds

Terms of germination of seeds

Definition 1.

Germination - This is the transition of seeds from the state of rest to the growth of the embryo and the development of the seedlings.

The prerequisite for germination of seeds is a rest period. If this period is significantly tightened to it stands artificially disrupt.

Methods of violation of the rest period

There are three methods of disturbing the rest period:

• Stratification;
• Scarification;
• Washing water.

Definition 2.

Stratification - Preparation of seeds to germination.

In order to prepare seeds, they are mixed with moisturized sand for a period of $ 30 $ to $ 90 $ days at a certain temperature of $ 5 ^ \\ CIRC \\ C $. Exposure time depends on the type of plant. During this period of time, physico-biochemical processes occur in seeds, which contribute to the germination of the seed.

When damaged, the peel opens access to air and moisture for the seed, which contributes to their swelling and germination. Damage is possible mechanical, or caused by a short-term action of strong sulfate acid.

Definition 4.

Washing water - The process of removing from the seed substances that brare germination.

External environmental factors for seed germination

Also important for germination of seed is germination energy. The energy of germination depends on the factors of the external environment, and characterizes the sowing quality of seeds.

Water, temperature, light, air, physiological active substances relate to seed germination factors.

Effect of air on germination

In germination, the seed breathes, while absorbing the oxygen necessary for oxidative reaction to the cells in the cells. These reactions stimulate division and growth of nucleus cells. In order to be convinced of the need for air, carry out experience.

Example 1.

Take three glasses and put dry wheat seeds in them. The first glass with a saucer, in the second, together with seeds, put wet watts and also cover the saucer, and the third water will be filled. Let's leave for a couple of days. In the third case, the seeds will not sprout, but only swell, since for the most germination, the seeds are not enough air, which is necessary for breathing.

Effect of light on germination

The reaction to the light is due to the action of it on the exchange of stimulants or inhibitors in the seeds. So distinguish the light-loving and dark and dark plants. Many seeds germinate better in dark place.

Effect of water on germination

Water is necessary for swelling seeds. During the swelling of the peel of the seed is damaged, then the spine and the embryo skelter appear. Water helps suck the necessary seed nutrients for the necessary germination. For the conviction of the need for this factor, we will conduct experience.

Example 2.

Take two tanks and put the beans seeds there. The first will simply cover a saucer, and put a wet watment to another and cover. After a couple of days, we note that in the second case, the seeds sprouted.

The amount of water for different plant species is different. So for legume plants, more water is needed in relation to cereal plants.

The temperature value for germination

An equally necessary condition for germination is the temperature regime. A certain plant has its favorable temperature. Some cultures germinate with $ + 2 ^ \\ Circ \\ C $, others above $ + 15 ^ \\ Circ \\ C $. Knowing the temperature preferences of cultures in agriculture, a sowing calendar has been developed.

The thermal-loving plants germinate, at high temperatures, are outputs from warm latitudes, and at low temperatures cold-resistant - immigrants from the northern regions.

Physiologically active substances for germination

In order for the embryo grow, it should eat. Seed nutrients are in endosperm or seedlies. With a limited reserve of physiological active substances, the embryo will slowly develop, or can die at all. To prevent this farmers, starting fertilizers contribute. The absorbing nutrients, in the embryo, the metabolism is met: the absorption of oxygen and the separation of carbon dioxide.

Note 1.

Thus, it can be concluded. To germinate, the seed requires the presence of water, heat, light, air and nutrients. And if we exclude at least one of the factors, the seeds will not sprout.

Transformation of substances in the germination of semen

With germination of seed in endosperm and cotyledons, there is a decomposition of spares, including proteins. At the same time, synthetic processes begins in the embryo, due to those substances that proceed to it.

The total number of nitrogen remains at the same level, despite the fact that the energy breakdown of proteins occurs, because the amino acids and asparagin are accumulated.

The amount of starch decreases sharply, but the amount of soluble sugars does not decrease. Sugar is spent on the process of breathing, which is very vigorously occurring in the germinating seed. As a result of breathing, the rich in the energy of the ADF and ATP substance is directly formed, water, carbon dioxide and thermal energy are distinguished. Sugar form fiber and hemicellulose. Minerals remain constant. Cations regulate osmotic pressure and colloid-chemical processes in new cells.

Plant seeds do not germinate immediately, they can stay alone for a long time. Only hitting the favorable conditions, they germinate, forming a new plant. In this way, germination - This is the transition of seeds from the state of rest to the growth of the embryo and the development of the seedlings.

The main necessary condition for the germination of seeds is to enter the seed water through the semi. After entering the water, the seed swells, the nutrients dissolve in water and the embryo can already be used to begin its growth and development.

However, water is far from the only condition of germination of seeds. The air is no less important, and the acidic oxygen in it. After all, the germs of seed, like all living organisms, breathe. Even dry seeds breathe, although very weak. Therefore, the seeds can not be stored in no air tanks, for example, in polyethylene packages. Seeds germinate in the soil, because it contains enough air.

Another condition of seed germination is the presence of spare nutrients. The embryo to grow should eat. Since he himself cannot synthesize organic matter, they should come from somewhere. This place is cotyledties or endosperm. If the reserve of nutrients is small, then the germ or develops slowly, or dies.

Thus, the plant's embryo, the absorbing nutrients of seed and oxygen, performs metabolism. In the process of metabolism, it highlights carbon dioxide.

The temperature also plays an important role in seed germination. To germinate seeds of different plants, different temperatures are favorable. Some germinate at temperatures above +15 ° C (cucumbers, pepper, corn), another just above +2 ° C (dill, radishes, wheat, rye, carrots). Therefore, in agriculture, various plants sow at different times, some in April, and some at the beginning of summer.

Plants whose seeds can normally germinate only at high temperatures are called heat-loving. Plants whose seeds germinate at low temperatures are cold-resistant.

The reason for which the seeds germinate at different temperatures is related to the origin of plants. Plants that occurred in warm latitudes, warm-loving. Northern regions of cold-resistant.

The light may also be a condition for germination of seeds. There are plants whose seeds can only germinate in the dark or only in light. Most often, the seeds germinate better in the dark.

When sowing seeds, the depth is important to which they are placed in the soil (sealing depth). At the same time, they are guided by the following rule: the larger the seeds of the plant, the deeper they are close in the soil. Very small seeds sow directly on the surface of the soil, and the beans seeds, for example, close by 4-5 cm.

Teacher:Ragimova Arza Magerramovna.

Municipal Autonomous Secondary Institution
Secondary school No. 44 Tomsk

Thing:biology.

Class:6, general education.

Subject:Conditions necessary for germination of seeds.

Annex to the lesson:presentation.

Form of the lesson:lesson with elements of design technologies.

The lesson on the topic "Conditions necessary for germination of seeds" is held in the 6th grade in the section Studying the topic "Seed".

Relevance.

At the present stage of training, it is necessary to especially pay attention to the individual personality development, the search and development of the creative abilities of the student, learning the skills of an independent solution to the tasks set in front of them. To form in students the ability to think independently, to apply knowledge, be able to plan activities, set questions and be able to find answers to them. The ability to effectively cooperate in a variety of mini groups. All this inevitably should lead to the search and introduction of new pedagogical forms and technologies in education. Some of these forms are research and design activities of students.

The essence of the research method lies in the organization by the teacher of the search, creative activity of students to solve new problems and problem tasks. Appointment of this method - a full assimilation of schoolchildren of creative activity

With the help of the research method, a creative learning of knowledge is organized, i.e., this method teaches schoolchildren to apply the knowledge-famous knowledge to solve problem tasks and mining new knowledge as a result of such a decision. In addition, it ensures the methods of scientific knowledge in the process of finding these methods. Obviously, the research method is a condition for the formation of interest, the need for independent, creative activity among students

The nature of the tasks in the research method: home practical tasks; solving analytical problems; Tasks are short-term and assumes the necessary specific period (week), the tasks of group.

At the lesson, I put two goals:

1) learning subject (didactic goal).

Tasks:

promote the acquisition of students

Generally educational skills (working with a textbook, to draw tables, issue observations in writing, formulate thoughts in the inner and external speech, to carry out self-control, carry out self-analysis, etc.);

Special knowledge and skills (assimilation of actual material on the subject);

Intelligent skills (analyze, compare, summarize, etc.).

Tasks:

to form research knowledge and skills in students:

Knowledge of the specifics and features of the process of scientific knowledge,

stages of research activities;

Knowledge of scientific research techniques;

The ability to identify problems, formulate hypotheses, plan an experiment in accordance with the hypothesis, integrate the data, draw output.

Equipment:bean Seeds, Pea, Petri Cups, Chemical Glasses, Computer With Multimedia Projector.

Preparation for the experimental part of the lesson:

The class is divided into 7 groups (one of them is expert). The whole class participates in the work. The Groups are held according to the principle of voluntariness, which allows you to remove the possible problems of interpersonal communication of students.

Each group is scientific name: botany; Yunnata; practice; young chemists; Young agronomists, young researchers, scientist council. Before each group, the teacher puts the goal, introduces the theoretical material, methods of setting and carrying out the experiment.

For 10-14 days before the lesson, expert groups of students under the guidance of the teacher laid the experiments demonstrating the conditions necessary for the germination of seeds. During the experiment, students are watching germination, care for germinating seeds and seedlings, make photos of study objects, prepare performances in accordance with the tasks.

The main stages of the lesson.

Stages lesson		Subject of research	Temporary implementation
Immersion in the topic through a problem task.
	botany	"What kind of structure have beans and wheat seeds?"
		"What conditions are needed to germinate seeds?"
	practices	What nourishes the embryo at the beginning of germination
	young chemists	does seeds breathe?
	young agronomy	why seeds are sown in different times?
	young researchers
	academic Council	expert
Generalization after each performance

Groups work on the proposed algorithm. Before it began, it is necessary to distribute roles for more efficient operation: the leader of the group (leader), the experiment director, a person who analyzes the results, speaker or co-supporters.

Group work algorithm:

1. Formulate the purpose of the study.

2. Add research tasks.

3. Pull the versions, hypotheses, designate problems.

4. Conduct an experiment.

5. Secure the result.

6. Place the result

7. Follow the output (analysis, generalization)

8. Submit the result of the study.

During the classes

1 hour (40 min.)

Immersion (3 min).

Teacher's introductory word. In the 6th grade, we began to study the section of biology - botany - the science of plants. With each lesson, we are increasingly receiving information about plants, and today's lesson is no exception.

We know that the plant begins his life from the seed. And how to give the life of the seed, what conditions are needed to germinate seeds and is the subject of today's lesson. And so they opened a notebook and write the topic of the lesson "germination of seeds."

You have a task, the answer to it you should give at the end of the lesson.

In the encyclopedia for children and schoolchildren in the section Archaeological excavations it is written: "Scientists have found wheat seeds that have lacquered in Earth more than 1000 years and did not sprout, although the ability to germinate did not lose. Why did this happen? After all, the seeds usually germinate a few days after sowing. "

To solve this problem, we will be helped by groups that led research work.

botany;

practice;

young chemists;

young agronomists.

young researchers.

At the lesson, there is a scientist council, which will summarize the work of all groups and decides whether we coped with the problematic issue.

Botany. Our group studied the question "What kind of structure have beans and wheat seeds?"

Consider the dry fruit of wheat - the grain. The oblong grain of wheat outside is dressed with a golden yellow leathery, which thus processed with seed skin, which cannot be divided. If you cut the wheat grain along, it can be seen on the cut that most of the grain is milded with endosperm, the cells of which contain nutrients. The germ of wheat is small, you can only consider it under a magnifying glass. It has a root, stalk and tieney. But he has one semilar. It does not contain the reserve of nutrients, fits tightly to the endosperma and looks like a thin plate. When the seed germinates, the nutrients from the endosperm cells come to the embryo through the seedlock.

So, the wheat seed has:

ocoplodnik, compared with seed peel; germ; endosperm.

Consider the structure of the bean seed. Outside the seed is covered with seed peel. It protects the seed from excessive drying. If you take the swelling of the beans in the water and remove the peel from it, the embryo will be discovered under the seed peel. It consists of two cotyledons and the root, stalk and tieney located between them.

So, the seed of beans consists of seed peel and the embryo, and the reserves of nutrients are in cotyledons.

Plants whose seeds consist of one cotyledti are called single-barrel.

Plants whose seeds consist of two cotyadal are called dicatular.

Teacher. Thanks to botany for interesting information.

The question is class - what is the name of the formation of a young plant from seed - germination.

It turns out that most plants have seeds that have fallen into the soil cannot immediately germinate. They need a period of rest - time during which the seed embryo has been attended outside the fetus. Pine seeds must relax for almost a year, freeze in winter and move warm in the rays of the Spring Sun. When the rest period is finished, the seed is ready to start its work on the transformation into a young plant. Way seeds can germinate as soon as they fall from the tree to the ground.

As well as seeds must have an element, i.e., the ability to germinate in appropriate conditions. The germination is determined by the percentage of seeds, of which normal seedlings developed.

What is called germination?

The germination of seeds is called their transition from the state of rest to the vegetative growth of the embryo and the formation of a young plant from it.

So, we learned how the seeds behave when only begin to germinate. And what happens next (video germination of seeds)

Brief description of the film.

1. During the germination of the seed, the first of it appears a small root? In order to look out, he has to break the seed peel.

2. If the seed is in the soil, the root always grows vertically down. Following this, an active growth of the stalk begins in the seed embryo. At first, getting out of the ground on the ground, it forms a loop, which gradually straightens and puts it on the surface strongly "thinning" semiodoli.

3. Between them is clearly visible by the kidney. She also grew up and began to green.

And so the guys write in notebooks.

By the method of germination of the plant are divided into two types:

1. Underground type,

2. Overhead type.

With any type of germination from the nucleus of the seed, a young plant is developing. It is called "seedlings".

The seedlings are formed due to the enhanced division of the educational tissue of the embryo. In the future, an adult plant, capable of breeding, will grow out of the seedlings, and everything will repeat again and again.

And how to get healthy seedlings, full and strong? The answer to this question was looking for our groups of experts.

yunnata; practice; young chemists; Young agronomists, young researchers.

The purpose of our research "Study of the conditions of germination of seeds"

1 group Yunnata

Our group interested the question: "What conditions are needed to germinate seeds?"

Two glasses placed the same amount of seeds. In the first glass, the seeds left dry. In the second a little poured water. Both glasses were closed with glass and put in a warm place. Five days in the glass, where there was water, the seeds sprouted. In a glass without water, the seeds have not changed.

Experience shows: “To germinate seeds need water "

Water is necessary for germination of seeds, as the embryo can consume only dissolved nutrients.

To germinate seeds of different plants, various amounts of water are required. For example, pea seeds absorb 1.5 times more than their mass. Therefore, pea seeds and some vegetable plants are wrapped before sowing. Corn grains are required 2 times less than their mass.

We took two sauces, put on them the same number of grams of peas and corn. Bought both sauces with the same amount of water. After a while we compared the saucer. In the saucer, where the seeds of peas were lying, there was no water. And on the saucer, where corn seeds lay, water remained. And after that, we definitely have been convinced that for each plant you need miscellaneous amount of water.

We conducted the following experience. Two glasses placed a little seeds. The first glass to the edges was filled with water. In the second cup, the seeds only darked. Glasses covered glass and put in a warm place. Five days in a glass with a small amount of water, the seeds sprouted. In the glass, filled with water, Nabuchly seeds, but did not sprout, but died. Here the water is ousted air,required breathing seeds.

Seeds of different plants require different amounts of air. The seeds of rice and Timofeevka will germinate even under water with a very small amount of air dissolved in it. Seeds of most flowering plants need abundance of air, and under water they do not germinate.

Two glasses placed a little seeds. On the bottom of each glasses

poured some water so that the seeds could germinate. Glasses covered with glasses. One glass was placed in a warm place, the other to the cold, in the refrigerator. When the seeds placed in a warm place were sprouted, compared them with seeds placed in the refrigerator. We saw that seeds in the cold did not sprout.

Experience shows that for germination of seeds you need warm.

If the seeds are enough water and air, but there is not enough warmth, they will not sprout, they will eventually die. One plants for germination of their seeds need a lot of heat, there are few different. For example, the seeds of cucumbers, pumpkins will germinate at a temperature of + 15, + 18 s, and pepper seeds at + 25 C. Pea seeds, radish, dill are approach at a temperature of +2, + 5 C. These features of the seeds are taken into account when determining the crops of sowing. Plants whose seeds require high temperature during germination, called heat-loving,and germinating at low temperatures call cold-resistant.

Teacher. And now we will make a scheme "Types of plants in relation to temperature."

Student Records the circuit on the board, and the guys in the notebook.

Teacher.Do you need light to germinate seeds?

The ratio of germination of seeds to the light can be checked by the simplest experience. We took two plates and put a cloth on each of them, Mocked her and placed it for each of them for germination of 20 bean seeds. Covered with a damp cloth. Then in one plate was placed in the darkness (in the cabinet), the other was left in the light. After 7 days they saw that the beans seeds, which were kept in the dark, developed better and sprout them more than in the light.

The experience confirms that the light is not needed for germination of seeds.

But there are some exceptions. Some seeds are only attributed to darkly, for example, the fine-fledged Ryzhik will not give rise to light, they will not sprout on the light of Facelius, the flame, the Persian Veronica.

Some seeds germinate only in the light. These are seeds of a series, tobacco, plant seeds growing in overly moistened places, swamps.

But for most of the seed, the presence of light is optional .

Students fix them in notebooks

Teacher. Well done Yunnata! Guys! And now let's remember, with what process the plants are needed

The answer is photosynthesis.

What substance is formed in the process of photosynthesis.

The answer is starch.

What does the embryo eat at the beginning of germination? Let's listen to practitioners.

Practice. In the course of research work, we found out that at the time of germination germina uses the reserves of nutrients prisoners. In germination, the starch seeds contained in the endosperm, under the action of special substances turns into sugar, which is soluble in water, the sugar solution flows to the germin. This is easily convinced if you taste the sprouted wheat or rye grains. They have a sweet taste.

The value of nutrients in seed germinations is easy to check on the experience.

On the wet litter of gauze, we put the same bean seeds. When they are swollen, cut off Seidoli. We were convinced that without seedlings, the seedlings are not growing. After all, the seeds contain nutrients, without which the seedlings can not live. If you cut off one seedlore, the seedlings will only have half of all stored nutrients, and it will be sick and weak from the lack of food.

From this experience you can make the following Conclusion: "The more nutrients, the larger the seedlings”. That is why the bean seedlings grew out of the whole seed, significantly surpasses the remaining seedlings.

. Therefore, for sowing it is necessary to take large seeds.

Teacher. Guys! Does seeds breathe? We will tell us the group "Young chemists".

Young chemists.A person and animal for breathing need oxygen. Oxygen supports burning. The burning mud is well lit, because the air contains oxygen. This is because when breathing is distinguished carbon dioxide, not supporting combustion.

We already know that air is needed for germination of seeds. Does seeds breathe? Do I need oxygen for breathing? What gas is allocated when the seed is breathing? To answer these questions, we will put experience.

We took 2 cans from colorless transparent glass. In one of them, there were dry non-sore seeds, and to another - the same number of sprouted seeds. Both banks closed the covers tightly and put in a dark place. The next day they checked if the composition changed with seeds? Put in the jar a burning match attached to the wire. The match continues to burn, because in a bottle with dry seeds, the air remained almost unchanged. Non-expressive seeds breathe weakly, and therefore the stock of oxygen in the bottle has been preserved almost completely. Then they opened a bottle with sprouted seeds and lowered the candle to the bottom. The candle will go out, because germinating seeds spent oxygen to breathe out of air, which was in a bottle, and allocated a large amount of carbon dioxide.

Experience shows that germinating seeds absorb oxygen and distinguished carbon dioxide, that is, breathe.This is natural, as plants - living organisms.

Conclusion: Air oxygen is an important condition for the germination of seeds and the development of a seedlings.

Seeds breathe day and night. Warmth is allocated warm. If in a jar with germinating seeds, wellclosed from all sides by cotton and felt, omit the thermometer, it is easy to notice the rise in temperature.

The heat that is distinguished by the breath of seeds is heating them. Especially much heat is distinguished when breathing germinating seeds. The raw sprouted seeds breathe vigorously near. Folded with a thick layer, raw seeds germinate and quickly heated. Embedes of such seeds do not die. Seeds are losing germination. That this does not happen, the seeds are removed on storage only dry and stored in dry, well-ventilated premises. Air access to seeds should be permanent. It is necessary for dry seeds, although they breathe weaker than germinating. Such conditions for storing seeds are created in modern granaries. (elevators).

Teacher. Thanks to the group of chemists. Guys! What conditions are needed to germinate seeds?

Pupils. For germination of seeds, the following conditions are necessary: \u200b\u200bwater, air, heat, temperature and seed nutrients.

young researchers.

We got the task to blame the effect of aloe juice on germination of seeds and compare the results.

We received information from the teacher, aloe juice is. Biogenic stimulant which affect the growth of the embryo.

On the basis of this information, we decided to observe how to act on the germination of the bean seeds. Fresh aloe juice.

For this we laid experience: with water (control), with the addition of fresh juice

Was delivered target: Jump how will act on the division and the growth of the cells of the seed seeds of the bean juice aloe.

The first stage - with water (control), the second option - in a wet medium of Petri dishes added arbitrarily several drops (5-6) aloe juice from sheet:

Table 1. The germination of bean seeds.

	Water (control)	Aloe Juice (Fresh)

As can be seen from the table, the speed of germination of seeds above the first day was observed in a water cup. On the second day, a noticeable leap in the germination of seeds we saw in a cup with fresh aloe juice, where ultimately all seeds sprouted on the third day.

In this way, Aloe leaves juice contributes to a faster seed germination and proved that aloe juice is biogenic stimulant.

We will continue our work. And in particular with different seeds and in different concentrations of aloe juice.

Teacher. Thanks to our researchers

The next stage is planting seeds.

Early spring seeds of only cold-resistant plants (wheat, oats, barley, peas) sow. Seeds of these plants germinate at low temperatures and abundance of moisture.

Plant seeds, more demanding to heat, have to suck when the soil warms up. However, with sowing seeds of thermal-loving plants (corn, beans, cucumbers, pumpkin, melon, tomato), too, can not be late.

Seed seeds need to be at a certain depth.

The depth of seeding depends on the size and properties of the soil. The larger the seeds, the deeper they sow them. In large seeds, sufficient nutrients and sprouts do not die, breaking through with great depths for a long time.

The practice was established that the small seeds of the turnips, Luke should be sowed to a depth of 1-2 cm, seeds of medium sizes, for example, the seeds of radish, cucumbers, - at a depth of 2-4 cm. Large bean seeds, peas, beans require a depth of 4-5 cm. If large seeds to sow less deeply, they do not have enough moisture.

Teacher. In an effort to grow plants, a person creates all the conditions necessary for the germination of seeds, and to get a good harvest, it is necessary to observe the timing of seeds and the depth of their sealing into the soil. This will tell us a group of agronomists.

Agronomas. Our group received a task to answer questions: Why seeds are sown in different times? Why depends the depth of seed seedings?

Our group did the following experience: we took 2 glasses and put in one small grains of wheat, and in the second - large. In total, we planted 6 grains (3 small and 3 large). At the beginning, the layer of the Earth was added 2 cm, then the first grain was planted, then the land was still poured 2 cm - they planted the second grain, they still poured 2 cm and put the third grain. All covered the layer of land in 1 cm and poured. The same was done with big grains. After 3 days, the first seedlings that was closer to the surface appeared, the next day the second seedlings appeared, asked after the first sprouted, the seedlings appeared on the third day, placed the very first, that is, deeper than all. A similar picture was observed with large grains.

Conclusion: Seed sealing depth is one of the most important seed crop factors.

The seed seed depth influence the properties of the soil. In the sandy soil seeds are somewhat deeper than in clay. In the upper layers of sandy soil very little moisture. Therefore, the seeds sitting in such soil shallow will suffer from lack of moisture. The air in sandy soil penetrates the greater depth, and the moisture is better preserved in deeper layers.

Clay soil is more dense and heavy. Already quite close to the surface in it there is little air, and moisture is enough in the upper layers. Therefore, it is not recommended to sow seed too deep into clay soil. Strict observance of the deadlines and rules for conducting sowing works are of great importance for increasing the yield of cultivated plants.

From the experiment concluded: the size of the seedling depends on the supply of nutrients in the seed. The more substances, the larger the seedlings. For sowing it is necessary to select large, healthy seeds.

Teacher.Guys! And if all the conditions for germination of seed are created. And the seeds did not sprout. Why?

Answer.Seeds did not sprout, because they contained the dead german.

Teacher.The proportion and give rise to a new plant is capable of only seeds with alive germs.

I think you did not forget about the question I asked you at the beginning of the lesson. So why wheat seeds who have lacquered in Earth more than 1000 years have not sprouted, although the ability to germinate has not lost., Why did it happen?

Answer - To do this, it was necessary to comply with all the conditions for germination of seeds.

Now it is time to provide the word to the scientific advice.

Academic Council.It was very interesting in the lesson. The guys in groups spent a lot of research work, showed a lot of experiences and we learned that the following conditions are needed to germinate seeds: water, air, heat and nutrients. And I will read the poem compiled by the guys of our class using the Internet.

Plants give us life
Even children know about it
But how do they appear
Plants in the world?

They grow out of seeds,
What have we seen with you more than once
But why do you ask
Do not they germinate every time?

My answer will be very simple
Find in the book you:
"To germinate seeds
Conditions need! "

And the first, of course
Water availability
And secondly,
Heat,
Be at least winter, even summer
And air whose composition is so complicated
For germination they need.

And if all this is folded
Sun, air and water
A little time
And with you, see how from the seed
Such a familiar person
Green little leaves
Shows a thin handle.

Teacher. Thanks to the Scientist Council, I think you all agree with their conclusions.

What experienced expert groups remembered more, impressed? What experiments did you want to repeat? Let's formulate the main thing that was allocated in the lesson. What was interesting in the lesson? And what was important in the lesson? Where can the knowledge gained in the lesson can be useful?

Students respond to questions, share their impressions from what they saw, express the desire to conduct independently experiments, allowing to establish the conditions of seed germination. Teacher Asks those who want to put experiments at home the course of work and the algorithm of formulation of one or another experience.

Thanks to all groups. Well done!

D / z: § 11, answer questions.

Thank you for the lesson. The lesson is over. All the best.

List of references:

1. Ivanov funds in folk medicine. - M.: Military Publishing House, 1992.

2. Vervillee with home plants. - M.: Pedagogy - Press, 1995.

3. Folder scientific research: lecture course. - Minsk: Informpress, 2002.

4..www. GOLDEN-YC. ***** / pages / 13.html.

To germinate seeds, water, air, heat and for many plants light are needed.

Especially a large stimulating effect on seed germination has red light.

Water penetrates the peel of the seed through the small hole - the semi-segment, as a result of which the seed swells. The need for swelling is primarily dependent on the composition of the seed. Seeds rich in fat absorbs 30-40% of water from the whole mass, rich in starch 50-70%, seeds with a large amount of protein - about 90% of water. Water is also necessary for dissolving the nutrients of the seed, which consumes growing germs. Seed swelling is accompanied by intensive enzyme activities. In seeds, spare nutrients are in the form of complex organic compounds. For example, in order for solid polysaccharide starch to be used as an embryo, it is necessary to hydrolyze it under the influence of a diastase enzyme, which precipitates the starch to the maltose soluble Disaccharide. Other complex substances are also split under the action of relevant groups of enzymes. At the same time, the energy used in the biochemical processes of the seedlings is exempt.

Great and give rise to a new plant can only seeds with alive germs.

The causes of the death of embryos are different:

1. from the defeat of harmful insects;
2. from the damage to mold mushrooms;
3. from drying during storage;
4. from too long storage, etc.

So, when germination of seed a number of consistently occurring processes can be distinguished:

1. seeds absorb a large amount of water and swell;
2. with a favorable temperature and air access - o2 (necessary for breathing, which is rapidly enhanced), the enzymes of seed cells go from an inactive state into active;
3. under the action of enzymes, insoluble spare substances are converted into soluble (starch - in sugar, fats - in glycerin and fatty acids, proteins - in amino acids);
4. the embryo, using soluble organic substances, is rolled into growth, and first grows the root, and then escape.

Period of rest

- Prerequisite for seed germination. Peace may be forced to be associated with the lack of necessary conditions for germination (peace of dry seeds). Organic peace is determined by the properties of the seed itself. In most cases, metabolic processes occur in such seeds (breathing sometimes growth of the embryo), but germination is inhibited. Such seeds, even in conditions favorable for germination, do not sprout at all, or germinate badly. The ability of seeds to be in forced to rest or organic peace developed in plants in the process of evolution as a means of experiencing unfavorable for the growth of the seedlings of the season. Therefore, not all seeds have the ability to germinate immediately after ripening (apple tree seeds, maple needs a long peace).]

The main reasons that prevent seed germination:

1. waterproof of the peel;
2. the presence of substances in incubating germination in the octurizer;
3. underdevelopment of the embryo;
4. the physiological mechanism of braking germination.

The main methods of disturbing rest period:

1. stratification - Seeds are mixed with wet sand - the process of preparing seeds to germination;
2. scarification - damage to the peel to accelerate germination;
3. washing water-in order to remove substances from the seeds that slow down germination;
4. processing with physiologically active substances (gibriline, cytokinin).

Seeds can be germinated only at a certain temperature: winter rye - at 2-4 degrees, and seeds of cucumbers - at 15-16 degrees. Required plants are seeded later when the soil warms up.

A very important condition for germination of seeds is air, so the seeds must be seen in the loose land, which contains a sufficient amount of oxygen. Oxygen is necessary for redox processes in cells. These processes stimulate the division and growth of the nucleus cells.

Conclusions:

1. That the seeds are sprouted, air is needed, water, heat.
2. If any condition is not - the seeds will not sprout.

The subject of the lesson: germination of seeds. The conditions necessary for germination of seeds.

The purpose of the lesson: to show the role of seed in the individual development of plants, introduce students with the conditions of seed germination, the dependence of this process from environmental factors, to form the knowledge necessary for the right sowing of seeds, the growth and nutrition of seedlings; Continue the formation of skills to discuss problem issues, analyze, work with various sources of information.

Tasks lesson:

1. Educational

To form and systematize knowledge of the conditions of germination of seeds, about the need for a certain temperature, humidity, air availability, spare nutrients, the depth of seed seed into the soil, light mode.

Establish the dependence of the life activity of seeds from environmental conditions, seed storage rules, planting seed agrotechnik.

2. Developing

Develop knowledge of the conditions for the extension of seeds, common biological concepts, beliefs in the natural nature of biological phenomena and material conditionality.

Develop the knowledge of the technique of the experiment, the ability to observe the process of germination, fix the results, formulate conclusions

Develop the ability to use the terminology, to work with various information sources, check in practice the loyalty of theoretical knowledge.

Develop intelligent skills: the ability to observe, analyze, compare, to establish causal relationships, draw conclusions.

3. Educational

Relieve a sense of responsibility, accuracy, accuracy, interested attitude to study, cognitive interest in the subject.

Equipment:

Seeds of beans, peas, rice. Pumpkins, oats, sunflower, Petri dishes, chemical glasses, computer with multimedia projector, presentation on the topic "Conditions, seed germination", Tables: "Structure of seeds of monocoons and dicotyledonous plants"

Type of lesson: Combined, laboratory work "Conditions necessary for germination of seeds"

Training Methods: Problem, Partial Search

Preparatory experimental part of the lesson:

In front of the students, the teacher puts the goal, introduces the theoretical material, methods of setting and conducting the experiment.

For 10 days before the lesson, students under the guidance of the teacher laid experiences demonstrating the conditions necessary for the germination of seeds. For the time of experiment, students are watching the germination process, care for germinating seeds and seedlings.

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Open lesson on biology

Teacher: Shchekoturova Yu.S.

Class: 6 "B"

The subject of the lesson: germination of seeds. The conditions necessary for germination of seeds.

The purpose of the lesson: To show the role of seed in the individual development of plants, introduce students to the conditions of seed germination, the dependence of this process from environmental factors, to form the knowledge necessary for the right seeding of seeds, about the growth and nutrition of seedlings; Continue the formation of skills to discuss problem issues, analyze, work with various sources of information.

Tasks lesson:

1. Educational

• To form and systematize knowledge of the conditions of germination of seeds, about the need for a certain temperature, humidity, air availability, spare nutrients, the depth of seed seed into the soil, light mode.
• Establish the dependence of the life activity of seeds from environmental conditions, seed storage rules, planting seed agrotechnik.

2. Developing

• Develop knowledge of the conditions for the extension of seeds, common biological concepts, beliefs in the natural nature of biological phenomena and material conditionality.
• Develop the knowledge of the technique of the experiment, the ability to observe the process of germination, fix the results, formulate conclusions
• Develop the ability to use the terminology, to work with various information sources, check in practice the loyalty of theoretical knowledge.
• Develop intelligent skills: the ability to observe, analyze, compare, to establish causal relationships, draw conclusions.

3. Educational

• Relieve a sense of responsibility, accuracy, accuracy, interested attitude to study, cognitive interest in the subject.

Equipment:

Seeds of beans, peas, rice. Pumpkins, oats, sunflower, Petri dishes, chemical glasses, computer with multimedia projector, presentation on the topic "Conditions, seed germination", Tables: "Structure of seeds of monocoons and dicotyledonous plants"

Type of lesson: Combined, laboratory work "Conditions necessary for germination of seeds"

Training Methods: Problem, Partial Search

Preparatory experimental part of the lesson:

In front of the students, the teacher puts the goal, introduces the theoretical material, methods of setting and conducting the experiment.

For 10 days before the lesson, students under the guidance of the teacher laid experiences demonstrating the conditions necessary for the germination of seeds. For the time of experiment, students are watching the germination process, care for germinating seeds and seedlings.

During the classes

Teacher's introductory word.

In the 6th grade, we began to study the section of biology - botany - the science of plants. With each lesson we get more and more information about plants And today's lesson is no exception.

Let's remember what is the value of plants in the nature and life of a person?

We learned that plants are the main suppliers of oxygen for all living on Earth. Plants contribute to our lives beauty and harmony. We do not get tired of admiring them.

Plants are a source of food for all heterotrophs - animals, a person. We use green parts of plants, fruits, vegetables, berries, mushrooms, seeds.

But in order to continue to use the gifts of plants, a person should know how to care for them, grow correctly, germinate.

Question: Where does the plant starting his life?

Answer: The plant begins his life from the seed.

Question: What is seed?

Answer: Seed - germ suspended in its development. (Record in notebooks)

Teacher: Let's remember what seed consists of?

A teacher, together with students, recall all parts of the seed, consider them and make entries in notebooks.

Now is not the time to exercise seeds, but nevertheless you all grouped them and, with you. Well done!

And how to give the life of the seed, what conditions are needed to germinate seeds and is the subject of today's lesson. Record the topic of the lesson in the notebook:"Seed germination. The conditions necessary for germination of seeds. "

Seeds of wheat, corn, pea and other plants are kept in a dry state in the granaries. There are cases of preservation of seeds for a decade. Seeds found in the thicker of ice, tombs, do not lose vitality even hundreds of years.

Question: Let's think about what germination is?

Germination is the transition of seeds from the state of rest to the growth and development of it seedlings.

The resulting plant from the seed is called a seedlings. For the seedlings to become like an adult plant, you need a lot of time. Seeds must survive the condition of rest.

Question: What is the meaning of this state?

Answer: Important adaptive value, as it protects seeds from premature germination.

Greater and give the beginning of a new plant are capable only seeds with alive germs, as it can die from the defeat of harmful insects, from drying out, from long-term storage of seeds and other reasons. To raise a high harvest of cultivated plants, a person takes care of the sowing material.

Problem: How to get healthy, full and strong seedlings? We will try to find this question for today's lesson.

In the process of germination, seeds allocate their stages, each of which performs its functional load.

Stages of germination of seeds:

1 stage - water absorption

Stage 2 - Seed swelling

3 Stage - Increased dimensions. Cell division.

4 Stage - the appearance of the root.

5 Stage - the appearance of germinal escape.

Seaman germination begins with the absorption of water: they swell. We swell both the courses and nonsense seeds. The swelling nonsense seeds are reworked, and the merry - germinate. Water activates substances that contribute to the transformation of insoluble starch (spare substance) into soluble glucose, which moves to the growth zone, the nucleus cells begin to share and increase in size. The first visible sign of growth is the appearance of the root. It breaks the peel of the seed, grows down, fastening the seed in the soil. Then the kidney appears - germinal escape.

Question: What conditions are needed so that the seed sprout?

Let's try to conduct a study.

The purpose of our study is "Studying the conditions of seed germination"

We suggested that seeds for germination are necessary: \u200b\u200bwater and air, heat, soil, food, light.

1. The test the need for water and air to germinate seeds.

To do this: the first glass was placed dry pumpkin seeds, in the second - the seeds were slightly poured with water so that they were air access, in the third - seeds were poured with water, filled with a glass of half, so that the water layer did not let the air to the seeds. Six days later, they discovered: in the first glass, the seeds were left unchanged, in the second, the seeds had roots, in the third - seeds died without air access, started.

From the experiment you can concludeThat seeds germinate in the presence of water when air access. Water is necessary to dissolve spare nutrients contained in seed (in endosperm or cotyledons) for the initial growth of the embryo.

The water has displaced the air required by the seeds for breathing. Seeds of different plants require different amounts of air and water. For example, rice seeds germinate even under water with a very small amount of air. After sowing rice, the field is poured with water. Seeds of most flowering plants need an abundance of air and will not be powder under water.

2. Expert the need for heat to germinate seeds.

One plants for germination of their seeds need a lot of heat, others germinate at sufficiently low temperatures. For example, the seeds of cucumber, pumpkins, pepper germinate at a temperature of +15 +18 degrees Celsius (these are thermal-loving plants). Seeds of pea, radish, dill can bring at a temperature of +2 degrees Celsius (these are cold-resistant plants). Consider Figure No. 136 in the textbook)

Experiment with a thermo-loving plant - pumpkin. One part of the seeds was placed in a warm place at a temperature of +20 degrees, another - in the cool, at a temperature of +5 degrees.

Five days later, they watched: in the warmth, the seeds quickly gave the roots, then the stalks, and the seeds that were in a cool place, only weakly "crumble"

From the experiment, we can conclude: In the sprouting of seeds, it is necessary to take into account the temperature conditions, to know at what temperature certain seeds germinate.

Question: What conditions are needed to germinate seeds?

Answer: Water, air and warm.

Question: What are these factors called?

Answer: these are factors of inanimate nature.t..Abiotic factors.

Question: Do you think that enough of these factors for germination of seeds?

Answer: No.

3. Let us examine the impact of the number of spare nutrients on seed germination

The endosperm of monocycle and semi-silders of dietary plants contain nutrients for the initial growth of the embryo. .

Petri seeds were placed in the first cup of Petri, with two seedlings, in the second - seeds who were removed in one Semi-sydola.

Five days later, full-fledged seeds with two seedlings were safely sprouted, gave roots, stalks and seedy leaves. In the second only part of seeds with one cotyledon, they sprouted, in non-sprouted seeds germin did not have enough nutrients for germination.

Then, in the first glass, the seedlings obtained from a full-fledged seed, in the second - seedlings from seed with a remote cotyledon. The first seedlings were healthy, strong, developed much faster. The second is small and weak.

From the experiment concluded: The size of the seedling depends on the supply of nutrients in the seed. The more substances, the larger the seedlings. .

4. Let's explore how the seed seed depth influences the soil.

For the experiment, we took pumpkin seeds and planted them into the soil at different depths. In the first glass, the seed was put on the depth greater than the rules of sealing, in the second - according to the rules of sealing to a depth of up to three centimeters. In the first case, the seed attended longer in time, in the second - faster and seedlings developed faster.

The depth of seal depends on:

1. Seed size:

A. Small Seeds Close up in the soil not very deeply at a depth of 1-2 cm, these are seeds of plants such as onions, turnip.

B. Surgery Semen Close up in the soil at a depth of 2-4 cm, these are seeds of plants such as radishes, cucumbers

B. Large seeds Close up in the soil at a depth of 4-5 cm, these are bean seeds, peas.

Working student with text Paragraph number 38, p.185

The smallest seeds have orchids. The length of the orchid seed is no more than 1 mm, 1 million orchid seeds weighs less than 28 g. The magnitude of the seed in no way affects the size of the plant, which will grow out of it: orchids grow larger than others from whom the seeds are larger. And a huge red tree begins his life with a tiny seed long not more than 1.6 millimeters.

2. Quality of soil.

In the sandy soil, seeds are sowing deeper than in dense clay, because The sandy soil is more loose than clay, it is faster losing moisture and dries. In clay moisture enough, but at a small depth there is very little air in it. In clay soil, seedlings are difficult to break into the surface to the light.

5. Let's explore how the light on the germination of seeds affects.

For the experiment, the seeds of oats were simed simultaneously in two pots. One pot was placed in a dark cabinet, the second is left in the light. Five days later, the seeds rose at the same speed both in light and in the dark.

From the experiment you can conclude That the germination of seeds does not depend on the presence of light, this is especially true of seeds with dark skinny, (sunflower seeds), because it does not miss the light.

Some seeds are only attributed to dark, for example, a grimel fine-grade, flavor, Persian Veronica.

Some seeds germinate only in the light. These are seeds of a series, tobacco.

6. The reader concludes what conditions are needed to germinate seeds.

Writing with students in the notebook Slide Schemes.

7. Question: Explain the meaning of the saying: "One day feeds"

So that the seeds remain alive by the time the landing, it is necessary to comply with the conditions for storing seeds.

Question: Seeds are laying for storage well-dried. "Why?"

In the period of germination, the seeds are actively breathing, energy and heat, seeds are heated and can die from high temperature, losing germination. Diseases may appear in wet conditions, mold, which leads to the death of seeds.

In the granaries install ventilation, the room is systematically ventilated.

With insufficient ventilation and high humidity in the grain, the temperature of the grain can quickly increase to 60 degrees. Grain becomes unsuitable for sowing. Therefore, it is stored on the elevators and constantly moisture meter measure the humidity and temperature of the thermometer.

Agrotechnical sowing is of great importance: the need to know the timing of seeds, loosening the soil before sowing, the properties of the soil.

Plants give us life

Even children know about it

But how do they appear

Plants in the world?

They grow from seeds

What have we seen with you more than once

But why, ask you

Do not they germinate every time?

My answer will be very simple

Find in the book you:

"To germinate seeds

Conditions need! "

And the first, of course,

Water availability, and secondly, heat

Be at least winter, even summer

And air whose composition is so complicated

For germination they need.

And if all this is folded

Sun, air and water

A little time, a little time

And with you, see how from the seed

Such a familiar person

Green little leaves

Shows a thin handle,

Like leaves with maple kidneys.

Conclusion:

Teacher: So, for seed germination, water, air, heat, seed nutrients, and to get a good harvest, it is necessary to observe the seed and depth of seed seed, which depends on the size of the seed and the properties of the soil.

Questions to students:

What experiences did you remember most, impressed?

What experiments did you want to repeat?

What was interesting in the lesson?

What was important in the lesson?

Where can the knowledge obtained in this lesson can be useful?

Fastening the knowledge gained in class

Homework: Paragraph number 38, tasks in notebooks with printed basis No. 139-143

Summing up the lesson: The teacher sums up the results of the work, assesses the students actively working at the lesson.