Category Archives: Plants

Why Flowers Smell So Good

Almost all flowers have a special scent that attracts us and makes them unique and irresistible at the same time. This smell is delicious, like a sweet, fresh and delicate perfume. But why do flowers smell the way they do?

The plant must resort to other strategies to transport pollen to fertilize other flowers. In some cases, the wind carries the particles through the air from one flower to another, ensuring pollination.

Plants synthesize special substances known as essential oils that they use to protect themselves from certain diseases, scare away predators or attract insects that help in pollination. These substances are mixtures of various chemical compounds that give the characteristic aroma to flowers, fruits, bark, leaves and seeds.

In many cases, plants concentrate these substances in both flowers and fruits, which act as chemical messengers. The scent travels through the air where it is detected by specific animals.

It is believed that pleasant smells are associated with substances that are pleasurable to consume, so plants are able to attract pollinators.

A picture of how flowers use their scent to attract insects and other animals.
The sense that flowers have for attracting different types of insects that will help them pollinate and reproduce.

Smell of flowers

Plants, like other living beings, are composed of different parts or organs with well-defined functions that make it possible for the natural cycle to be fulfilled:

  • Birth
  • Growth
  • Reproduction
  • Death

In the case of plants, the parts that make them up are:

  • The roots
  • The stem
  • Leaves
  • Flowers and the fruits

Although it must be remembered that not all plants flower and therefore do not produce fruits or seeds, as in the case of mosses and ferns. In flowering plants the flower is usually the most conspicuous part of the plant, and do you know why?

Because the flower is the reproductive organ of the plant, where pollen, a small yellow powder that allows the species to reproduce, is stored. Unable to move, the plant must resort to other strategies to transport pollen and fertilize other flowers. In some cases, the wind carries the particles in the air from one flower to another, providing pollination.

However, since the flowers need extra support, they have devised other methods to attract the attention of insects and get them so close that the pollen sticks to their bodies. Unknowingly, the insects continue their journey through other gardens, transporting the Pollen from one place to another to get the flowers pollinated. The most effective strategies for attracting birds and insects are the the use of shapes, colors, and scents, and the production of nectar (sweet liquid) that serves as food.

This process is known to scientists as the Pollinator Syndromes, which is a set of characteristics:

  • Shape
  • Color
  • Size
  • Nectar
  • Odor

By which each flower attracts a particular pollinator, thereby transporting pollen from one flower to another, which promotes reproduction and fruit formation.

Bad smelling plants

Flower that smells bad.
Some pollinators don’t just go for fragrant flowers like roses. They also like the stinky smell of flowers.

Although less common, it is also important to know that there are some flowers that give off a strong and even unpleasant odor (similar to rotting meat or a decaying animal) to attract certain flies and scavengers. Examples of these flowers are Rafflesia Arnoldii and Hydnora Africana. Those with a good odor, which are the majority, mainly attract birds, butterflies and bees.

The intensity of the scent emitted by each flower varies according to:

  • Time of day
  • Season
  • Climate
  • Age
  • Species

Whether the scent is pleasant or unpleasant, the purpose of flowers is the same: to attract pollinating insects so that they can reproduce, because they cannot move on their own.

Does the Banana Have Seeds

Despite what many people think, depending on the species analyzed, bananas do have seeds.

Banana is the name given to the plants grouped in the genus known as Musa. These species have large, green leaves that have Sheaths that form a pseudostem. The true stem of the banana, also called the rhizome, is underground and grows horizontally in the soil. The banana tree produces a fruit called banana, which is highly appreciated food by the entire world population and usually consumed fresh.

How do bananas reproduce without seeds

Despite being very widespread, the fruit details are not well known by the population, especially with regard to its structure. Many people believe that the little black dots in the center of the banana are seeds. However, these structures are unfertilized ovules. The cultivated banana is a parthenocarpic fruit, that is, it develops without fertilization and therefore has no seeds.

The development of seedless bananas occurred because of the selection of these fruits by producers who wanted to improve the quality of the product offered. Probably, the initial development of this type of fruit occurred due to some genetic change.

It is worth mentioning that even today it is possible to find bananas with seeds in nature. These wild bananas usually develop seeds in situations of environmental stress as a way to ensure their survival. An example of a banana that has seeds is the Musa balbisiana, native to South Asia (see photo below).

Picture of Musa balbisiana banana with seeds
Musa balbisiana is native to Australasia; it grows naturally in the Southeast Asian region from India to China, where hybrids with Musa acuminata have long been selected for cultivation. Does the banana have seeds?

Reproduction

Reproduction of the banana plant is usually vegetative, that is, shoots are separated from the mother plant, which gives rise to another specimen. In this case, the plant has no genetic diversity because it is identical to the mother plant. This poses a major problem, since from one specimen, which is easily infected with diseases, another with the same problem is produced.

Reproduction can also be done by rhizome fractionation, a technique in which parts of the plant stem are planted. There is also the possibility of propagating the plant through in vitro seedling techniques.

Did We Contaminate Mars with Genetic Material From Earth

Did We Contaminate Mars? – Since the early days of Red Planet exploration, humanity has hoped to find life there. NASA reduce the risk that what we discover are creatures we brought with us from Earth.

Imagine the day when astronauts will reach the planet Mars. They will take samples from the ground and from the air and search for what fascinates mankind the most – life. But even if they find signs of life there, such as remnants of genetic material, there is a pretty good chance that it’s not from Mars, but from the spacecraft and landings we sent there from Earth.

In 1971, a man-made object landed on Mars for the first time – the Russian Mars 3 lander. Later, several other landers and robotic spacecraft successfully landed on Mars. They probably brought bacteria from Earth, and perhaps some of the bacteria survived the long journey in the hostile conditions of space.

Many studies by the U.S. space agency NASA address this very problem, as it has multiple and dangerous consequences. Every spacecraft that NASA launches undergoes a rigorous cleaning process as much as possible in disinfected and cleaned spaces. But this is not enough, and even this clean environment can be invaded by other tiny bacteria and organisms (microorganisms).

Technicians clean the solar cells of the MAVEN satellite, which is currently in orbit around Mars |  NASA / Jim Grossmann.
Every spacecraft NASA launches undergoes a rigorous purification process. Technicians clean the solar cells of the MAVEN satellite, which is currently in orbit around Mars | NASA / Jim Grossmann

Two Directions for Infection on Mars

This phenomenon, of bringing living things and other forms of pollution from Earth to other planet is called forward contamination. In fact, the phenomenon is also known on Earth itself, from expeditions that have traveled to Antarctica and other remote locations. Such infection could seriously harm local populations. Moreover, contamination on Mars could skew the results of future studies.

The problem is not limited to forward contamination: at least theoretically, backward contamination could also occur. In that case, astronauts returning to Earth could bring with them an infection unknown in our world. As we saw with the COVID-19 Pandemic. A new bacterium or virus that appears unexpectedly can cause serious problems, especially if it is able to adapt to the human body or to other biological systems in Earth’s ecology.

Did We Contaminate Mars? Traces of the Curiosity SUV on the Red Planet  NASA / JPL-Caltech / MSSS.
Is that all we left on Mars? Traces of the Curiosity SUV on the Red Planet NASA / JPL-Caltech / MSSS.

We have probably “contaminated” Mars with life

The car-sized rover Perseverance landed safely on the surface of Mars on Feb. 18. It can only travel at a top speed of 152 meters per hour, but it has a suite of instruments with which it has conducted innovative experiments.

On board the three-meter-long robot is a machine that converted the thin, carbon dioxide-laden Martian air into oxygen and a helicopter that completed the first powered flight on another planet.

Microbes Might Survive the trip to planet Mars.
Microbes Might Survive the trip to planet Mars.

But is it possible that something else made it to Mars with all this equipment?

Could a trail of bacteria or spores have been accidentally transported from Earth to space. Maybe the Genetic material survived the trip to make the red planet its new home?

NASA and its engineers at the Jet Propulsion Laboratory (JPL) have precise and comprehensive protocols in place to ensure that their spacecraft are free of any organisms that might accidentally sneak into a space mission.

However, two recent studies show:

  1. Organisms may have survived the cleaning process and even the trip to Mars
  2. and how quickly microbial species can evolve in space

What would happen then if the robot finds traces of life on Mars?

The issue is very complex. We are looking for organisms that have the ability to survive in extreme conditions. That’s why we look for bacterial fossils. This type of research has to go through multiple angles of analysis.

Terraform Venus | Could Venus Become Habitable?

Terraform Venus: Leaving the Earth and Moving Into Space Has Been a Romantic Idea Since Ancient Times. Sooner or later, it will be necessary for the survival of the human race.

What if we turned one of the harshest and most dangerous places in the solar system into a colony? Not a city in the clouds, but a veritable second Earth?

That might be easier than you think. Venus is the hottest planet in the solar system. Its surface temperature is 460 degrees Celsius. That’s enough to melt lead. This is due to the strongest greenhouse effect in the solar system. CO2 captures heat easily. Just an increase from 0.03% to 0.04% in the Earth’s atmosphere, and we’re experiencing global warming right now.

The Venusian atmosphere is 97% CO2. Atmospheric density is 93 times that of Earth. Standing on the surface of Venus would be like diving to a depth of 900 meters. The pressure would kill you instantly. It’s a terrifying place.

Why Should We Bother Visiting Venus?

Gravity is a serious issue when migrating to the solar system, and prolonged low gravity is bad for your health.

Size wise, Venus could be the second largest habitable planet in our solar system. It will be a new home for billions of humans and trillions of animals. It has oceans, lush forests, and beautiful skies. Now, that’s a tall order. But with the ambition of future humans, it can be done.

It will take several generations to complete, and it will be a great challenge. Just as our ancestors did with the Great Pyramid.

Terraform Venus

Let’s just cool Venus down and remove the gas from its extremely heavy atmosphere. The volume is enormous, about 46.5 kilotons.

How do we remove it? There are several options.

We could use lasers from a giant solar thermal collector to heat the atmosphere and release it into space.

But that would require thousands of times the energy production capacity of the current human race, and it would take thousands of years to remove the atmosphere.

The other way is to sequester the atmosphere, to chemically react the CO2 into different compounds.

We’ll mine the Ca and Mg on Mercury and launch them via mass driver to Venus. It’s a motorized acceleration path that eliminates the need for rockets. The delivered elements would combine with the CO2 and be fixed as carbonates.

But not on a practical scale.

This method would require hundreds of billions of tons of material. It seems like a waste of material, and it would take too long.

An equally crazy idea is to put Venus in the shade.

Build a giant mirror to block out the sun and freeze the atmosphere. The mirror doesn’t have to be complex or huge.

If we make a huge flat surface near the sun, it will act as a solar sail and shift our position. It should be made of many parts, not just one circular object.

Multiple circular, angled mirrors can be placed to reflect sunlight back at each other. The mirrors are angled so that they reflect one after another until they send the light out the back. This balances the forces of front and back and holds them in position.

After a few years of setting up, things start slowly and then accelerate. For the first few decades, the atmosphere cools slowly, but remains too dense to be viable.

Then, after about 60 years, it reaches a critical temperature of 31 degrees Celsius.

Suddenly, the floodgates open. The CO2 liquefies under pressure and begins to rain down. The storm continues throughout Venus for 30 years. Suddenly, the pressure and temperature begin to drop simultaneously.

For about a century, the puddles became lakes and oceans. The surface temperature drops to -56 degrees Celsius, and the atmospheric pressure drops to seven times that on Earth.

When the temperature reaches -81 degrees Celsius, the ocean of CO2 begins to freeze and rain turns to snow.

Thus, Venus freezes and is covered with rocky oceans and huge CO2 glaciers. What’s left of the atmosphere is mostly nitrogen, at about three times the pressure of Earth.

Can Venus be Habitable?

But there’s a bit of a problem with frozen CO2.

Eventually, when Venus heats up, the CO2 ice will melt and fill the atmosphere again.

So we need a workaround to Terraform Venus.

One way is to cover the CO2 ocean with cheap plastic insulation and then cover it with Venusian rocks and water.

But some planetary scientists would be very opposed to building a planet with a ticking time bomb. A few ill-advised eruptions and all the CO2 would leach out at once, and everything would be ruined.

The other obvious solution is to eject all the frozen CO2 and stockpile it on a small moon. Mass drivers, not rockets, would be more efficient. Still, moving all that mass is a pretty tough challenge, and one that will take some time to solve.

In addition to handling the atmosphere, to terraform Venus we’ll need water, which we can get from the icy moons.

Jupiter’s moon, Europa, has twice as much water as Earth’s oceans.

Now, capturing a moon and moving it through the solar system is not easy.

It might be easier to cut through the ice on Europa with a formation of construction drones and shoot it into Venus with a mass driver.

Almost the entire process of getting the ice to Venus takes place on Europa.

When the ice hits the Venusian tether, it’s gently dropped into the atmosphere and falls as snow.

Instead, the Venusian tether catches the launched CO2 ice and accelerates it into orbit.

Likewise, the extra nitrogen could be removed, further reducing the atmospheric pressure.

In a few decades to a few hundred years, Venus will be covered by a shallow frozen sea, several hundred meters deep.

Several continents and countless islands will have formed, and it will look a little like Earth.

Now the final and most spectacular phase begins.

The atmosphere will be breathable, and life will begin. First, we need to reheat Venus with light.

A Venusian day is 2,802 hours, which is 116 days longer than Earth’s. So if we just remove the giant mirror, half of Venus will burn up.

Even if we clear the atmospheric pressure, the temperature alone is unsustainable.

The easiest way to create a day/night cycle on Venus

The easiest way to bring in energy is to use another mirror to illuminate the continents and melt the oceans.

This would give us complete control over the amount of energy and where it goes.

At this point, the atmosphere is mostly nitrogen, basically no oxygen. So the first inhabitants would be a large number of cyanobacteria.

Because they can release oxygen through photosynthesis. We can expect rapid changes in the atmosphere.

They’re thought to have brought oxygen to the Earth’s toxic atmosphere billions of years ago, helping animals to thrive.

In addition, cyanobacteria can fix atmospheric nitrogen and convert it into nutrients that organisms can use. Thus, the oceans become nutrient rich and ready for more complex life.

On land, we need to grind down the surface to create soil for nitrogen-fixing plants.

Eventually, billions of trees will form a great forest that will cover most of the continent.

Venus will Turn Green

To pick up the pace, CO2 will be strategically released to feed plants and cyanobacteria.

Plant-covered areas will receive additional sunlight from orbital mirrors, and plants will spend their days actively growing.

It may not have to be existing plants and animals.

As genetic engineering matures, our understanding of heredity and life increases. We may be able to create life as we need it to Terraform Venus.

It will take thousands of years in total to create an atmosphere in which humans can breathe.

The colonists will enjoy a new planet that is vast, resourceful, and sun-kissed.

They might even come up with new uses for the massive amounts of CO2 ice and nitrogen they’ve sequestered in space:

  • Industrial use
  • rocket fuel
  • terraforming of small planets like Mars

Billions of settlers and their descendants will call this planet home.

They will see images of the past. They’ll see images of the past, of Venus as the harshest of planets.

Terraforming Venus is Not Going to be Easy.

It’ll take a lot of success for this future to become a reality. But it’s possible.

It’s a technology that’s within the reach of a slightly more advanced, space-faring human race.

Terraforming: Changing the Atmosphere of a Planet

Terraforming is a theory about the hypothetical possibility of changing the climatic conditions on space bodies: moons, asteroids and stars. But first of all, of course, we are talking about planets. It is assumed that it is possible to make the climate, atmosphere and environmental conditions suitable for the comfortable life of humans, land animals and plants. Thus, terraforming will allow Earthlings to actively populate space.

Where the Idea Comes From

The idea of terraforming, like many innovative ideas, came from the world of science fiction. In 1942, American science fiction author Jack Williamson published the science fiction novel Collision Orbit. The protagonist of the book, a young engineer, terraforms an asteroid and makes it habitable. He cut a shaft to the center of the space object and set up a paragravitation system, was able to produce oxygen and water from mineral oxides, and built an apparatus that amplified the faint heat of the distant sun.

Jack Williamson was the first to formulate the concept of terraforming and gave the term its name.

How Terraforming Might Work

Considering the existing inventions and the technologies under development, it is assumed that terraforming will be done with equipment to be brought from Earth. The ideal and so far unattainable goal is to find materials for terraforming on the planets themselves. Or to bring microbes to the planet that can build a self-renewing ecosystem. What kind of microbes these will be is also unknown.

Although the idea of terraforming is still only hypothetical, political scientists are already getting involved in the debate. In particular, they are raising the question of governance:

  • who will govern the new planets?
  • Will they be part of Earth’s countries
  • will they have their own power and rulers?
  • How will territories be divided and what forms of government will there be?
  • is it worth investing large sums from the national budget in space exploration when the current population of Earth is unlikely to benefit from such investments?

Which Planets are Suitable for Terraforming

In Jack Williamson’s story, the main character was exploring an asteroid. In reality, however, this is virtually impossible. Scientists agree that a planet must initially have properties similar to those of Earth. For example, it is impossible to terraform Jupiter. In addition, the planet has a high level of radiation, incompatible with human life.

Ideally, the planet should be inhabited to begin with. Not the green men from the movies, but living bacteria. It would be easy to terraform a planet that differs from Earth mainly in temperature regime. The planet could be cooled by atomizing small particles like a “nuclear winter”. Or, conversely, it could be warmed by the release of greenhouse gases into the atmosphere.

Technological Requirements for Terraforming a Planet:

  • The presence of water. In liquid or solidified form;
  • Absence of radiation. As a prerequisite for life;
  • The presence of gravity. The planet must be able to hold an atmosphere with gas composition and moisture;
  • A magnetic field. So that the hydrogen does not leave the planet;
  • The presence of stellar heat and light. Some minimum is necessary to heat the atmosphere and the surface of the planet;
  • Surface. Impossible to build a gas planet;
  • Lack of asteroids. Frequent collisions with asteroids can destroy life on the planet.

Terraforming Mars

Right now, Mars is a prime candidate for terraforming. The planet’s initial conditions fit most criteria, and scientists are already beginning to think about what life might look like on it. Living organisms have not yet been found on Mars, but from information obtained by studying the surface, it is clear that the planet is favorable for the formation and maintenance of life.

There are huge temperature differences on the planet, from extremely cold to extremely hot, but theoretically with the development of technology it is possible to influence them and create a comfortable weather. Elon Musk proposes to use a thermonuclear strike to create two “tiny suns” that would heat carbon dioxide and provide comfortable warmth on Mars due to the greenhouse effect.

The main problem with terraforming Mars is that the planet lacks a magnetic field. According to a scientific article in Science Advances, for the first 700 years of its existence, the red planet had a strong magnetic field and was probably very similar to Earth. But about 3.6 billion years ago, the planet turned into a lifeless desert. Whether this can be changed is still unknown. Scientists propose to wait for the first manned missions to Mars and to start debating exploration only after careful study.

Can Venus be Inhabited

Venus appears to be another planet attractive for terraforming. Its surface is only 5% smaller than Earth’s. It is the closest planet to us: it takes about four months to reach it. By comparison, a flight to Mars would take about twice as long. And, very importantly, Venus is close to the Sun and does not lack heat and light. Its average temperature is 467°C and can theoretically be lowered to a comfortable temperature. Scientists propose to put special solar reflectors around the planet like walls. They will help to cool the surface and at the same time lower the pressure.

Despite all the planet’s attractiveness, there are a number of problems that are unlikely to be fixed. There is virtually no water on Venus. The water has to be brought in artificially, making settlement very difficult. Hurricanes rage on the planet, volcanoes erupt frequently, and there are acid rains. In addition, Venus, like Mars, has no magnetic field. If you invest in the conquest of the planet a large amount of resources, time and manpower, then theoretically its terraforming is possible. But the process will require much more effort than the development of Mars and is not considered so promising.


Where Do the Pollen Grains of Flowering Plants Develop?

The place of production of the pollen grain differs according to the plant:

  • In gymnosperms (seed-producing plants), the pollen grain is produced in strobiles.
  • While in angiosperms (flowering plants), the pollen grain is produced in flowers, specifically in the anther (the part of the stamen where pollen is produced).

The anther is a kind of tissue-covered pouch that forms spores. The oosphere (unfertilized egg), in turn, is produced in the ovary of the plant.

As plants reproduce, the pollen grain finds the archegonium, the place where the oosphere is produced and located.

The antherozoids (structure or organ producing and containing male gametes) are then released into the pollen tube. Then the pollen tube which moves toward the oosphere in the archegonium.

VIDEO: The Journey of the Pollen Tube

The pollen grain:

  • A pollen grain is the microspore of the plant, That is, the spore that contains the male gametophyte.
  • The pollen grain is produced in the anther of the flower, which is the the terminal part of a stamen of a flower.
  • When germinating, the pollen grain produces the pollen tube. This tube ensures the transport of male gametes to the oosphere.
  • When the pollination is done by the wind, it is called anemophilous pollination. In this case, the Odoriferous gland is absent.
About the author:

Daniel Vol has been writing about science and the environment since 2006.

Planet Venus: characteristics and facts

Have you heard about the Roman goddess Venus? Well, the name of this planet was given in honor of this deity. It is the second closest planet to the Sun and the closest to Earth. It is possible to observe the Venus surface with the naked eye from Earth. This is also possible because it is the brightest celestial body in the Solar System except for the Sun and the Moon.

Venus is a rocky planet, without satellites and without rings. It is an extreme planet; very hot, dry and with a surface pressure 90 times higher than that of Earth.

It is in fact the hottest planet of all despite not being closer to the Sun than Mercury. Although its dimensions are very similar to those of Earth, its atmosphere and composition make life highly unlikely.

The hot planet rotates very slowly in a retrograde motion, it rotates in a clockwise direction. If the North Pole is taken as a reference, from east to west instead of west to east like the rest of the planets. It takes Venus 243,187 Earth days to make a complete turn on itself.

The reason for the peculiar rotation of the planet is not known. If the Sun could be seen from its surface, it would appear rising from the west and settling from the east. Its day-night cycle is 116.75 Earth days.

General characteristics

Diameter: 12,104 kilometers.

Mass: 4.8673 × 10 24 kilograms.

Volume: 928,415,345,893 km 3.

Density: 5,243 g / cm 3.

Venus Surface temperature: 462 °C.

Venus surface

The planet is known to have a rocky surface thanks to NASA’s Magellan mission, which obtained information from 98 percent of the planet. Previously there were only speculations, because from space it is only possible to observe the planet’s clouds. Venus is now known to have a solid surface that features various shades of gray, with many craters and canyons.

Geology

About 90% of the surface of Venus appears to consist of recently solidified basalt with very few meteorite craters. The oldest formations present on the planet do not appear to be more than 800 million years old. Most of the soil being considerably younger, not more than a few hundred million years for the most part. This suggests that the planet suffered a cataclysm that affected its surface not long ago in the geological past.

Topology

Venus has two main continents like highlands, rising over a vast plain. Ishtar Terra is the northern plateau. The largest mountain on the planet (approximately two kilometers higher than Mount Everest), Maxwell Montes is located on this plateau. Ishtar Terra is about the size of Australia. In the Southern Hemisphere Aphrodite Terra is located. It is larger than Ishtar Terra. Its size is equivalent to that of South America. Among others, these smaller highlands include Lada Terra, Beta Regio, Phoebe Regio and Themis Regio.

Between these highlands there are some deposition plains and lowlands which include Atalanta Planitia, Guinevere Planitia and Lavinia Planitia. With the sole exception of Mount Maxwell, all distinguishable features of the terrain are named after mythological women.

Craters

The dense atmosphere of Venus causes the meteorites to disintegrate abruptly on their descent. The larger ones can reach the surface, creating a crater if they have enough kinetic energy. Because of this, impact craters smaller than 3.2 kilometers in diameter cannot form. For example, Howe Crater is over 23 kilometers in diameter.

Volcanoes

There are also more than 1,000 volcanoes that exceed 20 kilometers in diameter. Volcanic systems make up a kind of sinuous channels that extend for hundreds of kilometers and reach 4,000 kilometers in length. Venus is not thought to have movable tectonic plates like Earth. Instead, massive volcanic eruptions occur on the planet, flooding its surface with lava. Other recent discoveries suggest that Venus is still volcanically active.

Composition

Venus’ interior is probably similar to that of Earth. An iron core about 3,000 km in radius, with a rocky outer core that makes up most of the planet. According to data from the Magellan probe’s gravity meters, the crust of the planet may be harder and thicker than previously thought.

The magnetic field of Venus is very weak compared to that of other planets in the solar system. This may be due to its slow rotation, insufficient to form core dynamo. As a result, the solar wind hits the planet’s atmosphere without being filtered. It is assumed that it originally had as much water as Earth. However, being subjected to the Sun without any protective filter, the water vapor in the upper atmosphere disintegrated into hydrogen and oxygen. Then hydrogen escaped into space due to its low molecular mass.

The percentage of deuterium (a heavy hydrogen isotope that does not escape easily) in the atmosphere seems to support this theory. Molecular oxygen is supposed to have combined with atoms in the crust (although large amounts of oxygen remain in the atmosphere as carbon dioxide). Because of this dryness, rocks on Venus are much denser than those on Earth. This favors the formation of larger mountains, taller cliffs, and other geological formations.

The atmosphere of Venus

The planet’s atmosphere is made up mostly of carbon dioxide. Its clouds contain droplets of sulfuric acid and very small amounts of water. It is very thick and dense. That is why the Sun’s heat is being trapped in the planet’s atmosphere. Something similar to what happens due to the greenhouse effect on Earth, but on the hottest planet in the solar system, this phenomenon is enhanced.

The planet’s atmospheric pressure is 90 times that of the Earth. In short, it is an extremely hot planet. Probes that have managed to reach its surface have not withstood the temperatures for more than 2 hours. Normally, smaller objects that reach the planet are destroyed in its atmosphere.

Is there life on Venus?

An international team of scientists has recently detected traces of a rare molecule, phosphine, in the planet’s clouds. This molecule could be indicative of the potential presence of life on the planet. On Earth, this gas is produced by microbes that live in oxygen-free environments.

Astronomers have speculated for decades about the possible existence of such microorganisms in the planet’s clouds. They assumed that these microorganisms would float to avoid the planet’s scorching surface but would need a very high tolerance to acidity. The new research, published today in the journal Nature Astronomy, could point to such extraterrestrial “airborne” life.

Based on the findings, researchers put forward two hypotheses. Either the origin of the gas is found in other chemical processes unknown to date. Or the amount of phosphine found is due to the action of microorganisms. That is, there is life on the hottest planet in the solar system.

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How do plants ‘know’ when to flower and what triggers plants to bloom?

How do plants know when it’s time to flower? Like animals, plants also have an internal clock that prepares the internal cellular mechanisms in anticipation of upcoming environmental changes. This ensures that plants only perform specific tasks at the most appropriate time. For example, during the day, they perform photosynthesis, extracting energy from sunlight. However, completely different processes occur at night in the absence of sunlight. Many plants grow significantly more than during the day. Therefore, to distinguish the difference between day and night, plants have special receptors on their cells that can detect sunlight and start and stop metabolic processes as needed.

Picture of a vegetative organ that represents the origin of a new vegetable axis, from which leaves, branches and flowers can originate.
Buds form a flower.

One of these processes is what we know as flowering, or blooming. Researchers at Martin Luther University Halle-Wittenberg (MLU) have identified two genes that are key to this process. The ELF3 and GI genes control the plants’ internal clock, which monitors the length of daylight and determines when it is the right time to flower. The findings help to breed a better adapted plants to their environments.

Flowers are involved in the sexual reproduction of plants, but not all plants have flowers. Because of their function, flowers only appear at a certain point in the life cycle of plants we call angiosperms (with seeds contained in fruits).

Through circadian mechanisms, plants can anticipate certain regularities in their environment, such as the alternation of day and night, and adjust accordingly. This also includes flowering at the right time.

Plants orient themselves to the proportion between the hours of sunlight and darkness.

Some plants only flower when the days are particularly long. Others only bloom when the nights exceed a certain period of time. Different species of plants flower at different times of the year, when the days are of different lengths.

An example of this annual adaptation is the arrival of spring. The mechanism responsible for flowers emerging in spring is known as vernalization. And that it occurs at the exact time is essential for pollination to take place. According to a study by scientists at the University of Texas (USA), plants recognize this season because they “remember” that they have just gone through a long cold period thanks to a long RNA molecule called COLDAIR.

  • According to the authors of the research, this molecule creates a cellular memory for the plants when they pass 30 to 40 days of cold.
  • At that time, a gene called FLC, which has been dedicated to suppressing flower production during the fall and winter, is silenced, and the plant prepares to flower.

The amount of light is not the only external source of information for the plants’ circadian clock.

The ambient temperature also changes during the course of the day and the year. In future research, scientists will try to understand how temperature influences the flowering of plants and whether temperature can compensate for the lack of information about light.

Most plants have adapted to their original environment in such a way that they require a specific ratio of sunlight to darkness in order to flower. New findings could allow plants designed to flower elsewhere to produce good yields.

Photosensitivity in plants (How do flowers know when to bloom?)

Besides chlorophyll, plants have three other classes of light-sensitive pigments:

  1. Phytochromes are mainly sensitive to red light, and to a lesser extent to blue light.
  2. Cryptochromes are particularly sensitive to blue light. They are also used as signal molecules when the phytochromes “catch” light.
  3. Phototropins are not involved in the regulation of the daily rhythm. They control the phototropism of plants, i.e. the plant grows towards a light source.
  4. The plant regulates its sensitivity to light by producing phytochromes and cryptochromes, intensified in the morning. During this time the plant is most sensitive to light.

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