Why cross? About why cross-subsidization has become a problem not only in the electric power industry

105. Let us explain where the name double fertilization in flowering plants comes from.
In flowering plants, during fertilization, two fusions occur: the first sperm fuses with the egg and forms a zygote, the second merges with a large central cell and the endosperm is formed.

106. Let’s label the elements of the development cycle of a flowering plant, indicated by numbers in the figure.

1. mature plant
2. flower
3. pollen grain
4. ovary
5. ripening fruit
6. ripe fruit with seeds
7. seed
8. young plant.

107. Let's connect the parts of the flower with the fruits formed from them.

108. Let’s write down the pollination methods indicated in the figure.

1. Self-pollination.
2. cross pollination.

109. Let us explain why cross-pollination is more common than self-pollination.
Cross-pollination provides a variety of traits in offspring, since different organisms reproduce, rather than just one (as in self-pollination). This is more beneficial in terms of evolution. That is why in nature, plants have developed numerous mechanisms that prevent self-pollination. There are also a large number of pollen carriers (animals, wind, humans).

110. Let's fill out the table.

111. Let's distribute wind-pollinated and insect-pollinated plants.
Wind-pollinated: birch, oak, hazel, rye, corn, alder.
Insect-pollinated: linden, apple tree, clover, rose hips, fragrant tobacco, snapdragon.

112. Let us denote the sequence of actions during artificial pollination.

Many people know that cross-pollination is one of the most common methods of plant propagation. But information about why most plants chose this particular method, as well as about the different types, is not so common.

What is it

Pollination is the process of transferring pollen from the anthers to the ovule (common among gymnosperms) or the stigma (common to angiosperms). As a result of this, the female organ - the kidney or ovule - begins to develop, transforming into a fetus.

There are two most common types of pollination - self-pollination and cross-pollination. The first option is less common. In this case, pollen falls from the anther onto the pistil of the same flower, often even before its petals open. On the one hand, this is much more reliable - the number of barren flowers in this case tends to zero.

Cross pollination is the process of transferring pollen from the anther of one flower to the pistil of another. And this option, despite its great complexity, is found much more often among plants - in almost 90 percent of higher plants. Why is cross-pollination common in nature?

Types of cross pollination

To date, experts have identified two types of cross-pollination in plants - xenogamy and geitonogamy.

Geitonogamy is the process of pollination that involves the stamens and pistil of different flowers located on the same plant. That is, the tree is quite capable of pollinating on its own and producing fruit even in the absence of relatives nearby.

Therefore, experts have long debated whether this is cross-pollination or, rather, a special method of self-pollination takes place. The fact is that there is no exchange of genetic material here, and this is precisely the main purpose of cross-pollination.

But xenogamy is a completely different matter. The process is exactly the same, but it must involve flowers located on different plants. In order to protect themselves from accidental pollination of flowers on the same plant, some species have even developed a protective mechanism - separation of the sexes. At the same time, in the flowers of one plant there are only pistils, and in the other - only stamens. Therefore, the possibility of self-pollination is completely excluded.

Who helps pollination

Of course, the main assistant in cross-pollination is insects, primarily bees. Bestiality takes place here - this is the term used to describe any pollination of plants performed with the help of representatives of the animal world.

Here we can distinguish two rather rare subspecies:

• myrmecophily, when pollination is carried out exclusively by ants;
• cantharophilia - here beetles act as the main pollinators.

But this occurs only in relict plants that have survived to the present day.

Another case of bestiality is ornithophily - pollination by birds. This kind of crossover is not very common - it is found mainly in the tropical zones of America, because the only birds that contribute to pollination are hummingbirds.

Finally, chiropterophily - pollination by bats - is quite common. And plants using this method are also common only in warm countries, mainly in the jungle. Bats, licking sweet nectar from flowers, carry pollen on their tongues and fur.

Less common are anemophily (pollination by wind) and hydrophily (here pollen is transferred from flower to flower by water - found in some gymnosperms and algae).

It is now clear that pollination can be carried out using a variety of methods. But which one is the most common?

Prevalence of different pollination methods

The lion's share of plants that cross-pollinate do so through bestiality. Yes, it is insects, birds or mammals that pollinate almost 80 percent of higher plants.

Anemophilia lags significantly behind the leader. No more than 20 percent of plants use wind to transport pollen.

But hydrophilia is the least common. Less than 1 percent of all plants trust the transfer of pollen to water flows - in reservoirs or after rain.

Key Benefits

It's worth understanding why cross-pollination is so common.

As noted above, the number of barren flowers is almost completely absent in plants that use self-pollination. But at the same time, cross-pollination turned out to be more viable - this is proven by the abundance of such plants.

In fact, everything is simple here. In self-pollination (as in geitonogamy), the plant reproduces on its own. Only the genetic material it has is used and, as it turns out, this is a losing strategy.

Indeed, with xenogamy, plants that grow from seeds obtained by crossing two plants receive the advantages and characteristics of both parents. That is, if one tree grew in arid soil and managed to adapt to it, and another, on the contrary, grew in a swamp and survived, then the new tree that became their offspring will equally easily adapt to both a lack of moisture and its excess. Consequently, the likelihood that it will die in unfavorable conditions is sharply reduced.

It is thanks to this that cross-pollinated plants began to dominate throughout the world, confidently displacing competitors that appeared on Earth millions of years earlier.

Ways to Attract Pollinators

It was noted above that four out of five plants are used for pollination by animals - from mammals to insects. Of course, at the same time they developed an appropriate mechanism for luring them.

The most common is the presence of sweet nectar. Many millions of years ago, in an effort to attract pollinators, some plants acquired cells capable of secreting a sweet substance. The experiment was successful, and as a result, many thousands of descendants appeared, producing nectar with a pungent odor. Such plants primarily focus on animals and insects with a keen sense of smell.

But there are also plants that use ornithophily. And birds, as you know, are almost devoid of smell. A different technique was used here - larger and brighter flowers that have almost no scent. They are excellent at attracting hummingbirds, who know that sweet nectar awaits them inside.

Conclusion

From this article it becomes clear what cross-pollination is, as well as what the main advantages of this method are. At the same time, the article provides information about different methods of pollination with the involvement of various external forces. This will allow you to understand botany much better and be known as a person with a broad outlook.

1. What is a flower?

A flower is a modified shortened shoot used for seed propagation.

2. What structure does it have?

The pistil and stamens are the main parts of the flower. The perianth is located around the stamens and pistil. The perianth consists of two types of leaflets. The inner leaflets are the petals that make up the corolla. The outer leaves - sepals - form a calyx. The thin stalk on which the flower sits in most plants is called the peduncle, and its upper, expanded part, which can take different shapes, is called the receptacle.

3. What is the structure of the stamen?

The stamen has an anther, inside which pollen ripens. The anther is located on the filament.

4. What is the structure of the pistil?

The pistil has a stigma, styles and an ovary.

5. What is called an inflorescence?

Inflorescences are groups of flowers located close to one another in a certain order.

6. What process is called fertilization?

The process of fusion of male and female gametes is called fertilization.

Questions

1. Why is fertilization called double in flowering plants?

Fertilization in flowering plants is called double, because Two sperm penetrate into the ovary of angiosperms, one of them fuses with the egg, giving rise to a diploid embryo, the other unites with the central diploid cell.

2. How is the plant embryo formed?

Two sperm cells penetrate into the ovary of angiosperms. One of the sperm fuses with the egg. The zygote formed by the fusion of gametes is divided into two cells. Each of the resulting cells divides again, etc. As a result of repeated cell divisions, a multicellular embryo of a new plant develops.

3. As a result of what process occurring in the ovary is the endosperm formed?

The second sperm fuses with the secondary nucleus located in the center of the embryo sac, which leads to the formation of a triploid nucleus at the central cell. It divides to form endosperm cells, which store nutrients.

4. What does the seed coat develop from?

The seed coat of seeds in flowering plants is formed from the integument of the ovule.

5. What methods of pollination do you know?

There are two main types of pollination: self-pollination and cross-pollination. In self-pollination, pollen from the stamen ends up on the stigma of the same flower. In cross-pollination, pollen from the stamens of flowers of one plant is transferred to the stigmas of flowers of other plants.

Also, depending on who acts as the pollinator, a distinction is made between natural (in nature) and artificial pollination. In artificial pollination, humans act as the pollinator. At the same time, he sometimes deliberately transfers pollen from the stamens to the stigmas of the pistils.

6. What is the purpose of artificial pollination?

Artificial pollination is carried out to develop new varieties and increase the yield of some plants.

Think

Why is cross-pollination more widespread in nature than self-pollination?

During cross-pollination, a recombination of hereditary characteristics of the paternal and maternal organisms occurs, and the resulting offspring can acquire new properties that the parents did not have. Such offspring are more viable.

Quests

After analyzing the text of § 24 and Figure 102, explain what the structural features of the pollen grain shell are associated with.

The structural features of the pollen grain shell are determined by the way it is transferred from the stamens to the pistils.

In wind-pollinated plants it is dry, lacks sculpture, mostly has pores, and is produced in large quantities.

The pollen of insect-pollinated plants is larger or very small, sticky, and has a sculpture and a large number of apertures.

Quests

1. Study additional text. Determine the similarities and differences between wind-pollinated and insect-pollinated plants.

Similarities: the abundance of pollen in the flower and the presence of inflorescences (in any case, this increases the chances of pollination).

Traits characteristic only of insect-pollinated plants:

Large single flowers, brightly colored petals or tepals, the presence of nectar and aroma.

Large, sticky, rough flower pollen (sticks well to the hairy body of the insect).

Traits characteristic only of wind-pollinated plants:

There are no bright, large and fragrant flowers. Inconspicuous, usually small flowers, feathery stigmas, anthers on long hanging threads.

Very small, light, dry pollen (adapted to wind pollination).

2. Observe flowering plants in the school area. Determine which of them are wind-pollinated and which are insect-pollinated.

Wind-pollinated: birch, oak, aspen, alder.

Insect-pollinated: clover, dandelion, rose, linden, apple tree.

Quests for the curious

Analyze Figure 105. Draw a conclusion and discuss it in class.

In lower plants, the gametophyte reaches its greatest development, but as plants become more complex, the gametophyte is suppressed and the sporophyte becomes the predominant form. The greatest reduction of the gametophyte is observed in seed plants. It is striking that both among lower and higher plants, all large and complex organisms are sporophytes.

Reasons: change of habitat to land-air, which is less stable. Diploid organisms are highly resistant. Recessive mutations remain in the heterozygous state.

Paying the costs of some electricity consumers at the expense of others is one of the main problems in the development of electricity in Russia. Such a system developed in the 1990s and was exclusively socio-political in nature, when, in the wake of upheavals in the economy, the authorities did not want unnecessary reasons for riots. In recent years, market participants and experts have repeatedly approached the issue of abolishing cross-subsidies or at least changing the system, and in the context of the need to “jump” the economy and the task of increasing GDP growth rates above the global average, the discussion has intensified.

“The intersection is probably one of the main problems that has developed over more than two decades. If we take the Soviet experience of supplying electricity in the interests of industry and in the interests of the population, then price parity in 1982 was 3.5 times: prices for industry are 3.5 times higher than for the population,” he said last week at the “round table" to the Chairman of the Duma Committee on Energy Pavel. In 1992, this figure dropped to one and a half times, and now tariffs for the population are lower - a coefficient of 0.8. At the same time, several types of cross-subsidization have developed in Russia - containing prices in a number of regions (in particular, in the Far East), supporting renewable energy sources, and maintaining non-market tariffs for citizens. The result of the latter: tariffs for legal entities are growing at an accelerated pace, including budgetary organizations (and here “holes” appear in the budgets), small and medium-sized businesses and agricultural producers, says Zavalny.

Moreover, estimates of the volume of cross-subsidization vary, including among government authorities. The deputy cited an estimate of 380 billion rubles. According to calculations by the Institute for Problems of Pricing and Regulation of Natural Monopolies, this is about 280 billion rubles. for 2016, and now - about 300 billion, its director told Gazeta.Ru.

“The total volume of crossroads between consumer groups today exceeds 220 billion rubles, and if measures to reduce it, planned by the government several years ago, are not implemented, this figure could double in the next 5 years,” believes the director of electricity at Vygon Consulting. Alexey Zhikharev.

Accordingly, this system diverts company funds. And in general, non-market, Dolmatov points out. “It’s probably reasonable to assume that, of course, this is a wrong situation that needs to be corrected,” he believes, calling the proposals of some enterprises reasonable.

An oasis of cheapness

At the same time, tariff decisions for the population are made by the constituent entities of the Russian Federation, and the tariffs themselves vary from region to region. The highest are in Chukotka and Kamchatka. The Irkutsk region stands apart, where the tariff is only 1.01 rubles. (from July 1 it will be increased to 1.06 rubles). For a long time, the regional authorities have taken credit for low energy tariffs; there were periods when they did not change for years (for example, under Governor Boris Govorin).

“The Irkutsk region is a striking example of tariff distortions; the volume of “crossroads” here is close to 3 billion rubles, which is exactly how much industrialists overpay. How justified such benefits are is the question,” says Alexey Zhikharev from Vygon Consulting.

It was for the Irkutsk region, which unites assets, that it proposed to cancel the intersection. The Irkutsk and Bratsk aluminum smelters operate in the region, which are in a difficult situation due to American sanctions. “Consumption by enterprises is about 40% of the balance of demand in the price zone of Siberia, therefore, a reduction in the output of finished products or the closure of aluminum smelters will greatly reduce the volume of electricity consumption in Siberia, which will create risks for the operation of the Siberian energy system in extreme conditions: “idle” water discharges from hydroelectric power plants and the operation of thermal power plants at the minimum possible load,” the company said.

The NP Market Council supported the proposal to reduce cross-subsidies in the Irkutsk region, the head of the NP said earlier. As Kommersant reported, they supported the reduction of “crossroads” in the Irkutsk region. The Ministry of Energy has not yet developed a position. “We have indeed received the corresponding instruction, it is still in progress,” the press service of the Ministry of Energy indicated to Gazeta.Ru.

The governor who represents, as expected, spoke out against the cancellation. The reason is, in his opinion, the sensitivity of this issue for the population.

At the same time, electricity tariffs for the urban population in the Irkutsk region are the lowest in Russia: 1.01 rubles. per kWh (single-rate tariff) with an average per capita income of 22.4 thousand rubles. in 2017. For comparison: the average Russian tariff is 4.3 rubles/kWh with an average per capita income of 31.5 thousand, and in the Krasnoyarsk Territory with similar climatic conditions - 3.78 rubles/kWh with an average per capita income of 28 thousand rubles. Compared to some regions, the difference is even higher: for example, residents of the Altai Republic are poorer, but pay more - 4.81 rubles. with an average per capita income of 19 thousand rubles. The lowest per capita income in Siberia, according to Rosstat, is in Tuva (13.8 thousand rubles). But even there the tariff is more than 3 times higher than in Irkutsk.

Based on the consumption standards approved in the Irkutsk region, the monthly payment for an Irkutsk family of four living in a three-room apartment with an electric stove (95 kWh per person in 2017) is about 384 rubles. For the same electricity consumption, a family from the Altai Republic will pay 1,790 rubles, in the Krasnoyarsk Territory - 1,436 rubles. The difference is significant.

The process of setting tariffs for electricity and utilities for the population is strictly regulated by federal legislation, the administration of the Irkutsk region said. If the payment (total, not just for electricity) increases more, then the regional authorities must compensate for the difference from the budget. “Accordingly, the region understands that this will be an additional burden for it, and, naturally, does not seek to increase tariffs for the population... First, due to the fact that they do not want to compensate, and second, of course, the region does not yet see incentives for itself, which this will bring political benefits,” explains Ilya Dolmatov.

Tough social policy also interferes with the introduction of social norms, adds. “The issue of introducing into tariff regulation such a concept as social norm, which implies maintaining a low level of tariff for the population only within a certain limit, was initiated more than 10 years ago during the reform of RAO UES of Russia, but strict social policy opposes its development,” the expert points out. According to him, mining of bitcoins by citizens in their apartments can also add to the problem.

“Judging by the fact that the press is full of information about the growing network of Siberian miners, cheap electricity has become a magnet for them, so we are already faced with multi-level cross-subsidization. As far as we know, the issue of regulating mining with the parallel implementation of monitoring systems for such activities is already being considered by the government and the Central Bank,” Zhikharev added.

Reform of the cross-subsidization system is necessary, experts say. But this system must be abolished gradually throughout the country.

“It is clear that it is quite difficult to correct the situation at once. But to say that this is a normal situation and does not need to be changed is obviously also wrong, because the consumer, including Rusal, rightly states that they bear an unreasonable additional tariff burden,” points out Ilya Dolmatov. According to Alexander Zhikharev, the issue must be resolved gradually - over 5-7 years. “But even such a horizon will not allow setting tariffs for the population on the principle of “inflation minus”; in regions such as the Irkutsk region, growth rates should be above 20%,” the expert states.