What is the difference between mosses and multicellular algae. What is moss? Moss types. Flipping through the pages of biology
Mosses, they are bryophytes, are spore plants that have a stem, green leaves, but are devoid of roots, vascular systems, flowers and seeds. Scientists, however, do not consider the organs of mosses to be real stems and leaves, but we will not go into scientific subtleties now.
Mosses are small plants. Most land mosses only reach a few centimeters in height. There are Lilliputians who are five times smaller than a millimeter. But among aquatic mosses there are real giants with a meter-long stem. The modest size of mosses is probably due to the absence of a conductive system. Without it, how would they deliver water and nutrients to all ends of a large body?
Mosses have short, thread-like outgrowths of the lower body. They resemble roots, but serve mainly to attach to the soil. And mosses absorb water with the entire surface of the body.
Sometimes the name moss is used, confusing different plants. For example, the well-known “deer moss” () is not a moss at all, but a plant from a completely different group, it is a lichen.
Where does moss grow?
Mosses are common inhabitants of damp, shady places. They can be found on rotting wood, trunks and branches, rocks, stones, concrete, along the lower edge of buildings where moisture accumulates. Sometimes they appear on rooftops and between paving stones. It is not surprising that these lovers of moisture have also mastered reservoirs.
Having drilled a glacier in Antarctica not so long ago, the British discovered moss that had lain here for one and a half thousand years, since the time of the Roman Empire. Moreover, the moss placed in the water sprouted! This suggests that once in Antarctica it was the same as in the Northern Hemisphere.
It is widely believed among tourists that mosses often settle on the northern side of large stones, rocks, tree trunks. The north side is really more often and longer wet. But this does not happen everywhere and not always. Yes, and different types of mosses have different requirements for humidity and light. So mosses can settle from any part of the world, and you need to be careful on this basis.
How is moss different from algae?
The main differences between mosses and algae are that mosses:
How are mosses different from ferns?
Mosses cannot be confused with ferns because mosses:
- no real large leaves and long roots;
- specialized tissues are very poorly developed;
- cells have a half, not a double, set of chromosomes for most of their lives;
- spores do not ripen on leaves, but in a box, which is connected to the stem with a leg;
- a branched thread grows out of the spore, and not a small plate;
In addition, mosses are not treelike and appeared on the planet before ferns.
What is moss good for?
Like other living organisms, mosses are important in the general cycle of matter. They provide food to many animals and microorganisms, and change their habitat in the course of life. For example, covering the soil with a dense carpet, they can lead to waterlogging. Unpretentious mosses are among the first to settle where it is difficult for other plants to live (for example, in the tundra). Dying and decomposing, mosses enrich the soil with humus. Many frogs lay their eggs in the moss, and bird nests are lined with moss.
Man has long used swamp moss sphagnum. It grows to the top, the rest of the stem dies off. But since the plant contains phenol, which is deadly for bacteria, it almost does not rot. Gradually accumulating and compressing at the bottom of the swamps, moss forms a common fuel and chemical raw material - peat.
Another property of sphagnum is the ability to absorb huge amounts of moisture. Therefore, dry moss is used as bedding for livestock, and during the war it happened to replace bandages. 
In addition, many mosses are very decorative, their bright green pads adorn aquariums, greenhouses, garden compositions, etc. In the ancient capital of Japan, the city of Kyoto, there is the Saihoji Monastery, where the Moss Garden has been created for a century now. It is recognized as a UNESCO World Cultural Heritage Site. Instead of lawn grass and flowers, mosses cover the ground here. There are 130 of them here. They decorate miniature ponds, moss rugs surround rocks and trees.
Mosses generally easily absorb not only moisture from the air, but also many chemicals. This makes it possible to detect atmospheric pollution using these plants. By the way, the destruction of the natural environment threatens many mosses with extinction. The Red Book of Russia includes 60 species of mosses.
To understand what mosses are, you need to study the most ancient eta - the highest type, isolated and numerous. In our time, there are almost 30 thousand varieties of mosses on the entire planet.
Classification
Botanists have discovered and studied all known species, the classification of which is based on differences in the morphological structure, methods of distribution and the structure of spore boxes. can be conditionally divided into the following classes: deciduous, liverwort and anthocerot mosses.
Deciduous mosses
What are deciduous mosses? They are otherwise called briopsids. This is a large class with about 15 thousand species. Representatives of this group are recognized as the most highly developed of all plants of this department. Briopsids are very diverse, both in shape and size. Sometimes they reach considerable sizes. The most viable stage of their existence is the gametophyte. The plant looks like a stem with single-layer leaves arranged in a spiral. Bryopsids reproduce by spores. They are distributed in the tundra, swampy and humid areas. Representatives: cuckoo flax,
liver mosses
What are hepatic mosses (liverworts)? They number about 8.5 thousand species and are divided into two subclasses: Marchantium and Jungermann liverworts. The predominant viable stage is the gametophyte. Externally, the plant resembles a flattened "stem" with leaves arranged along. Propagated by spores with the help of an elater (special spring). Liverworts are common in tropical and temperate climates. Typical representatives: hairy blepharostroma, polymorphic marchantia, barbilophosia lycopsus, ciliated ptylidium.
Anthocerotus mosses
What are Anthocerote mosses? This class of mosses is often regarded by specialists as a subclass of liver mosses. It includes almost 300 species.
The sporophyte stage predominates. Externally, the plant looks like a rosette-like or lobed thallus. These mosses are found in temperate humid and tropical climates. The representative of the class is anthoceros.
Generalized characteristics of mosses
So what are mosses? These are undersized plants, the height of which can vary from 1 mm to 60 centimeters. They grow on tree trunks, on the walls of houses, on the ground, in fresh water and swamps. Due to salt intolerance, plants are not found in the seas and on saline soils. Most often, the structure of mosses is very simple - stems and leaves. But the roots of the plants in question are completely absent. They absorb water and nutrients with rhizoids or the whole body. Adaptation to terrestrial existence has led to the fact that mosses have integumentary and mechanical tissues, as well as new cells that perform a conductive function. The plant is a perennial, most often small in size (only a few mm high), less often large (up to 60 cm). Its body looks like a thallus (anthocerotic or individual liverworts) or is divided into a “stem” and “leaves”. Attachment to the substrate and absorption of water is carried out by outgrowths of cells, the so-called rhizoids (they, as a rule, do not have a conducting system).
It also does not differ in intricacy. These are large light green or slightly reddish curtains. They have upright "stems", with clustered leafy "branches". Without rhizoids, the moss stem is upright (gradually dying from below), leafy in several rows, with numerous leafy lateral processes, which are collected at the top of the stem into a dense head. Throughout the rest of the stem, the branches are collected in bunches. The latter consist of 3-13 branches hanging and spaced from the stem. At the top, the “branches” shorten and gather into a dense head. Colorless aquifers with pores make up the outer layer of the “stem”.
Single-layer "leaves" of sphagnum include two types of cells: photosynthetic and aquifers. The first are worm-shaped and contain chloroplasts located between aquifers. There are many such cells, which allows the sphagnum to absorb a large amount of water. Sphagnum sporophyte is a rounded box in which spores appear, with a lid. When the spores mature, the pressure inside the box increases, as a result of which the lid opens, and the ripe spores are thrown out. This process takes place in warm weather for better spore dispersal.
What are green mosses? Kukushkin flax can be attributed to their bright representatives. Its “stem” is covered with hard, dark green subulate “leaves”. It has rhizoids and grows up to 30-40 cm. The leaves of the moss are recurved and erect, with an elongated membranous sheath and a vein protruding from the top. The “stem” has a primitive conducting system and dioecious gametophytes. The top of the "stems" ends with antheridia and archegonia. After fertilization, a sporophyte develops from the zygote, which is a box on a long stalk for the maturation of haploid spores in it. The box is covered with a falling cap with thin, drooping hairs, similar to linen yarn. The moss box is subdivided into a lid, a neck and an urn. Inside the box is a "hidden" column filled with barren cells. Around the column is the sporangium. The urn and the lid adjoin a ring consisting of cells with thickened walls. This ring is responsible for dropping the urn and separating it from the lid.
Moss propagation methods
The sexual generation predominates over the asexual one. The reproductive organs of moss are formed directly on its body. These are the archegonia and antheridia mentioned above. Archegonia are responsible for the formation and development of one immobile female gamete, and antheridia for many male gametes. In the fertilized female gamete (the condition is the presence of water), the asexual generation of moss begins to develop - the sporophyte. This is a kind of box on a leg, attached to the body of the moss. It contains many spores that are able to germinate under favorable conditions, forming a new plant. Some species are able to reproduce vegetatively. At the same time, the thallus is separated from the adult organism, which is attached in close proximity to the plant, and begins an independent existence and reproduction.
moss spread
It is more difficult to determine where there is no moss than to tell where moss grows. This representative of the flora is distributed almost everywhere - from the tropics to the polar regions. In tropical regions, moss grows mainly in mountainous areas and in forests, i.e., where high humidity prevails. Sometimes soil covered with mosses is also found in arid areas, since this plant has the ability to temporarily stop its vital activity during the dry period, and resume it with the advent of moisture. Basically, mosses predominate in the temperate and subarctic zones of the northern hemisphere.
Moss and its meaning
The value of mosses in nature is enormous. Firstly, thanks to these representatives of the plant world, the landscape water balance is regulated, because they are able to accumulate large reserves of moisture in the thallus. Secondly, the moss plant creates a special biocenosis, especially in areas where it completely covers the soil. In addition, this group has the ability to accumulate and retain radiation. The value of mosses for animals is also great, because bryophytes are the main type of food for some individuals. And in human life, this plant also plays an important role. So, many species are effectively used in pharmacology. And the peat formed after the death of mosses is used as fuel.
Mosses are plants that are complex and rather peculiar, so they are studied by a botanical science called bryology. Scientists have managed to explore and discover many, until recently, unknown plant species. What is moss? This is a group of higher plants, numbering about ten thousand species, which are united in seven hundred genera and one hundred and ten families.
The main difference between these plants and others that inhabit our planet is the fact that in their history they practically did not change. Sometimes they are mistakenly considered lichens.
Spreading
The group of plants that are united by the name bryophytes includes simply arranged spore terrestrial plants, with special reproductive organs - sporogons.
Bryophytes are widely distributed throughout the world. Most species grow on damp soil, tree trunks, rotting wood. Some have adapted to live in extreme dry environments, such as open cliffs and deserts, where development is only possible during the wet season.
An example of this is the desert tortulla, which grows on stony dry rocks and slopes. It develops only when there is moisture. This moss spends a dry period in a state of suspended animation: the metabolism of the plant slows down so much that any of its manifestations are almost imperceptible.
Moss also grows under water (in rivers, lakes and swamps). What is a plant that lives in the seas, science is still unknown. Mosses develop very rapidly in the humid tropics, sometimes hanging in a long “beard” from the branches of trees or covering trunks and soil with a thick carpet. In addition, they form a large part of the vegetation cover of the tundra and peat bogs.
Only Schistosteg moss lives in dark and damp caves. But these days, its luminous emerald stars are quite rare.
moss structure
Bryophytes are rather small plants: their length does not exceed a few centimeters, although there are aquatic species whose length can reach thirty centimeters. They all contain the green pigment chlorophyll, essential for photosynthesis, although their outer color can vary from light green to almost black. The body has leaves and a stem, although these terms are used rather conditionally in this case, since bryophytes do not have vascular tissues.
It can be a leaf-shaped flat structure - a thallus. There are no roots either, therefore, in the soil or other substrate, they are attached with filamentous long rhizoids. Unlike most vascular plants (cycads, ferns, flowering plants, conifers), mosses do not have tissues that transport moisture and nutrients throughout the plant.
Mosses have mechanical and integumentary tissues, as well as special cells that perform a conductive function. The moss stem without rhizoids is erect. It is leafy, with a large number of lateral processes collected in a dense head at the top of the stem. On the rest of its part, the branches are collected in bunches. The latter make up from three to thirteen branches, which hang down and are slightly spaced from the stem. At the top, they shorten and gather into a rather dense head.
The outer layer of the "stem" consists of water-bearing colorless cells with pores. Single-layer "leaves" include two types of cells: water-bearing and photosynthetic. The first are worm-shaped. They contain chloroplasts, which are located between aquifers. There are a lot of them, so moss can absorb a fairly large amount of water.
The sporophyte is a round-shaped box in which spores are formed. When they ripen, the pressure inside the box increases, the lid opens, and the spores fly out. This happens in warm weather.
plant species
All bryophytes are united in a taxon of the highest order - Bryophyta. It is divided into three classes:
- Anthocerota.
- Liverworts.
- Leafy.
Representatives of the last group are the most common. In humid coastal areas, anthocerotes and liverworts also play an important role in the cover. In terms of the diversity of life forms and species, the first place should be given to the Musci class. It is made up of three more subclasses:
- Andreevs.
- Sfang.
- Leafy.
liver mosses
What is hepatic moss? This is the oldest variety, a bright representative of which can be considered hairy blepharostomy, which has a characteristic flat, spreading shape. Most mosses of this species have both true leaves and stems. Most often, this type of moss grows on the soil, on deadwood, on stones along the banks of rivers and streams, on stumps, forming loose and dense, in combination with other bryophytes, tufts, extensive carpets.
Another large class is bryophytes. All of them, in accordance with the arrangement of leaves, stems and the method of fixing in the ground, are divided into orders. This type of moss forms dense cushions from several millimeters to several centimeters high, often covering vast areas with a dense carpet.
Anthocerotus mosses
Another common variety is anthoceroth moss. What is a plant outwardly reminiscent of liverworts, you can see in the photo below. The name of the mosses of this species comes from two Greek words anthos, which translates as "flower" and keros, meaning "horn", since the shape of the plants is a lamellar rosette (thallus) of dark green color with a diameter of one to three centimeters, which fits snugly to the soil, as well as sporogons (horn-shaped outgrowths) about three centimeters high.
Tortula wall
The plant is distinguished by small pads. Moss of this species grows on limestone stones, on the walls of houses built from such material.
Cirriphyllum hairy
This moss (you can see the photo below) forms light green loose tufts. It needs calcareous, nutrient-rich soil. Cirriphyllum can often be found in bushes, in forests. He is a frequent visitor in the gardens.
Hylocomium brilliant
This type of moss settles in forests, on roadsides, in meadows, in quarries. It forms cascades, which consist of individual steps.
green moss
In the life cycle of this variety of plants, as, indeed, in all bryophytes, the haploid generation, the gametophyte, predominates. The box-shaped sporophyte develops on the gametophyte. The largest and most common moss, whose name is somewhat unusual - cuckoo flax.
Perennial plants grow on the outskirts of swamps, in swampy forests, where it forms thick and dense sods. The upright stem of cuckoo flax, as a rule, does not branch. Its height is not more than forty centimeters. The leaves are linear-subulate with a median vein. This moss has no roots. They were replaced by multicellular rhizoids - filamentous located on the lower part of the stem. They absorb water from the soil, and in addition, help the plant to strengthen.
Green moss cuckoo flax looks like a sprig of coniferous plants. Its length can reach fifteen centimeters. Quite often, it is this variety that covers the soil in the forest. Experts know that if cuckoo flax appears on the soil, this may mean that the soil is waterlogged. It creates dense and rather extensive soil covers that contribute to the accumulation of moisture. This leads to the formation of swamps.
Sphagnum
Unlike most varieties of green mosses, the popular name for sphagnum is white moss, the photo of which we have posted in this article. A perennial marsh plant that forms sphagnum bogs. The structure of sphagnum mosses is not much different from other varieties. These are large light green or reddish curtains. They have upright "stems" on which clustered leafy "branches" are located.
More than forty species of sphagnum are found in Russia, and more than three hundred in the world. Often found in the forest and tundra zones of the Northern Hemisphere, in the Southern Hemisphere it is much less common and only high in the mountains. A feature of this plant is that, having no roots, its lower part gradually dies off and becomes peat, while the upper part continues to grow. Places where white moss grows are called "white moss". Just like green mosses, sphagnum accumulates a lot of moisture in the body and contributes to waterlogging of the soil.
Mosses and algae belong to the Plant Kingdom. Both classes were evolutionary stages that Flora had to go through in order to surprise a person with a giant sequoia, a blooming orchid, or a ruddy apple hovering over Newton.
mosses
mosses are representatives of higher spore plants, along with ferns, horsetails and club mosses. None of the representatives of this group blooms, does not produce fruits or seeds. They reproduce asexually, producing spores, or sexually, but the fertilization process is possible only in the presence of a moist environment. The most common representatives of mosses are cuckoo flax, sphagnum, polytrix hairy, brium, dikran and eriopus.
Sphagnum
In the external structure of mosses, there is a difference between individuals of the sexual and asexual generation and individuals bearing male and female sex cells. Therefore, mosses are classified as dioecious plants. Both female and male individuals have a stem, which is densely covered with leaves. The upper leaves are traditionally bright green in color due to the presence of chlorophyll, the lower ones are usually yellow-brown due to the destruction of the pigment in low light conditions. Mosses have no roots. They are attached to the ground by rhizoids, multicellular hair-like processes. Rhizoids anchor the plant in the soil and are involved in the absorption of nutrients by the moss. But the same nutrients can enter the plant through other organs.
On the tops of some mosses, you can see long thin processes, on top of which a box with a lid is held. These are individuals of the asexual generation that have developed from a fertilized egg. Over time, they lose their green color and the ability to photosynthesize, so they feed on the individual of the sexual generation. A box with a lid - sporangium, after the spores in it mature, opens. If the spores get into a highly moistened soil, then they germinate in the form of a green thread, similar to filamentous algae. Such a "thread" grows, and individuals of the female and male sexual generation are formed from some of its cells. Despite the alternation of generations, the sexual generation predominates in the life cycle of mosses.
Mosses are considered the pioneers of the terrestrial space; they are common in almost all natural areas of the land, as well as in the shallow waters of fresh water bodies. Mosses regulate the water regime of soils, stimulating their waterlogging. Sphagnum moss is the main plant that forms peat, and is also one of the oldest dressing materials due to its bactericidal properties.
Seaweed
Seaweed- the very first and ancient representatives of the plant kingdom. There are about 50 thousand species of these organisms. Among them there are unicellular, multicellular and colonial species. In the cells of all algae there are plastids of green, brown, red color, which determines the taxonomic affiliation of the plant.
Red algae (Parphyra and Phyllophora) A feature of algae is "binding" to the aquatic environment - to freshwater or salty reservoirs. But there are specimens that live in Antarctica on the snow, on the wool of sloths in South America, or enter into symbiosis with fungi, forming lichens.
Algae can reproduce sexually, asexually, or vegetatively using broken portions of the thallus. In brown and red algae, collections of cells are observed that perform the same functions as the tissues of higher plants.
Algae enrich the reservoir and atmosphere with oxygen, produce a lot of organic matter and play a role in the formation of sedimentary rocks and soil. Algae are fed to pets, used as fertilizer, confectionery, medicine, or used as a natural water purifier.
Findings site
- Mosses are more complexly organized than algae.
- Algae appeared much earlier than mosses.
- Among the algae there is a large group of unicellular, all mosses are multicellular organisms.
- Most algae live in the aquatic environment, most mosses live on land, but with a high percentage of humidity.
- The body of moss is differentiated into organs; only in the most developed algae can one observe the prototype of tissues.
- Mosses have external differences between males, females, between sexual and asexual generations. In algae, all individuals of the same species are the same.
- Mosses cannot reproduce vegetatively, but algae can.
Tests
620-1. The accumulation of what group of plants contributes to waterlogging of the soil?
A) lycopsform
B) horsetail
B) mossy
D) ferns
Answer
620-2. The stem with leaves in the process of evolution first appeared in
A) algae
B) mossy
B) horsetail
D) ferns
Answer
620-3. Mosses represent a dead end branch in plant evolution because
A) more highly organized ferns originated from them
B) they did not give rise to more highly organized plants
C) more highly organized horsetails originated from them
D) they evolved from unicellular algae
Answer
620-4. What are the characteristics of mosses?
A) adventitious roots develop from the stem
B) spores are formed in a box
C) they have no escape
D) pollination precedes fertilization
Answer
620-5. Mosses develop from spores
A) a box on a leg
B) seed
B) green thread
D) sprout
Answer
620-6. The adaptability of sphagnum moss to life in conditions of excessive moisture is manifested in the presence of
A) rhizomes with adventitious roots
B) cells with chloroplasts
B) dead cells
D) rhizoids
Answer
620-7. Representatives of which department of the plant kingdom are shown in the figure?
Answer
620-8. What plants belong to the Bryophytes department?
A) living on land and reproducing by seeds
B) leafy, without roots, reproducing by spores
C) all plants in wet habitats
D) all herbaceous plants
Answer
620-9) What adaptations to the absorption of large amounts of water appeared in the process of evolution in mosses?
A) rhizoids - outgrowths on the stem
B) large dead cells
B) spore boxes
D) cells of thin integumentary tissue
Answer
620-10. In green mosses, unlike algae,
A) cells have large and small nuclei
B) fertilization occurs in the presence of water
C) the thallus is divided into tissues and organs
D) sexual and asexual reproduction
Answer
620-11. What division of higher plants does the plant shown in the picture belong to?
A) angiosperms
B) Gymnosperms
B) ferns
D) Bryophytes
Answer
620-12. How are bryophytes distinguished from other plants?
A) in the process of their development, alternation of generations occurs
B) reproduce by spores
B) have leaves, stem and rhizoids
D) capable of photosynthesis
Answer
620-13. Ferns, unlike green mosses, have
A) rhizoids
B) roots
B) leaves
D) stems
Answer
620-14. From spores of green moss cuckoo flax develops (s)
A) a growth in the form of a green plate
B) pregrowth in the form of green threads
B) plants with leaves
D) seeds of the future plant
Answer
620-15. Higher plants have no roots
A) Tsvetkov
B) Conifers
B) moss
D) Ferns
Answer
620-16. Ferns are much more widespread on Earth than mosses, since they
A) have a developed root system and multiply more efficiently
B) appeared in the course of evolution earlier and managed to better adapt
C) are widely grown by man for their needs
D) successfully distributed by various animals
Answer
620-17. Mosses have the simplest structure among higher plants, since
A) they have no roots
B) their stem is unbranched, with narrow leaves
C) they form organic substances from inorganic
D) they have air cells
Answer
620-18. Why do mosses represent a dead end in plant evolution?
A) they have not mastered the ground-air habitat
B) they evolved from algae
C) they do not have roots and reproduce by spores
D) they did not give rise to more highly organized plants
Answer
620-19. What department of the plant kingdom is represented in the picture?
A) ferns
B) Gymnosperms
B) Lycopsoid
D) Mossy
Answer
620-20. Which group of organisms includes green plants that do not have roots, reproduce by spores, in the life cycle of which the sexual generation predominates?
A) bryophytes
B) ferns
B) gymnosperms
D) lycopsform
