The plant kingdom is divided into 2 sub-kingdoms - higher plants and lower plants. The lower plants are algae, the higher ones are mosses, ferns, horsetails, club mosses, gymnosperms, angiosperms.
Seaweed
They differ from higher plants in that do not have tissues(conductive, mechanical, etc.) and do not have organs(roots, leaves, stems). The whole body of the algae is a single thallus (thallus). There are unicellular algae.
spore plants
Mosses, ferns, horsetails and club mosses reproduce by spores (asexual reproduction). Out of the controversy grows germ (gametophyte), it produces gametes (eggs and floating sperm). Fertilization requires water. After fertilization, a zygote is formed, from which a new plant grows - sporophyte(spores are formed on it in sporangia).
MHI considered to be the first plants to land on land. They first develop stems and leaves. Differences of mosses from other higher plants:
- No roots, instead of roots rhizoids.
- There are tissues, but they are poorly developed (especially mechanical and conductive), because of this, all mosses are small grasses.
- The gametophyte dominates the sporophyte(is a leafy plant). Sporophyte - box on a stalk, grows on a gametophyte.
- From the spore, a green thread grows into a pregrowth (protonema), and then a gametophyte.
Peat deposits are gradually formed from white sphagnum moss.
FERN, HORSEtail, PLUNA have not only a stem and leaves, but also roots, and well developed tissues. They were widespread in the Carboniferous period, it was from them that coal deposits were formed.
- Ferns produce spores on the underside of leaves.
seed plants
They differ from all previous divisions in that their male gametes do not float in water. They are found inside pollen that is carried by the wind.
Angiosperms (FLOWERS) currently occupy a dominant position in the biosphere of the Earth. Seeds of angiosperms are covered with a shell (pericarp). Only angiosperms have: flowers, fruits,, vessels in the xylem.
ALGAE - MHI
1. Establish a correspondence between the characteristic and the group of plants: 1) green algae, 2) mossy
A) do not have tissues
B) do not have organs
B) have boxes with spores
D) some representatives have aquifers
D) the sporophyte develops on the gametophyte
E) contain unicellular and multicellular organisms
Answer
2. Establish a correspondence between the signs and groups of plants for which they are characteristic: 1) Green algae, 2) Leafy mosses. Write down the numbers 1 and 2 in the order corresponding to the letters.
A) a sporophyte develops from a zygote
B) there are no tissues and organs
C) a pedunculated box develops on the gametophyte
D) reproductive organs develop at the tops of the shoots
D) there are unicellular and multicellular forms
E) in most species, the body is represented by a thallus
Answer
ALGAE IN EXC. FROM MOSS
Choose three correct answers from six and write down the numbers under which they are indicated. Algae, unlike mosses,
1) unicellular and multicellular plants
2) autotrophic organisms
3) reproduce by spores
4) do not have tissues and organs
5) belong to lower plants
6) play the role of producers in the ecosystem
Answer
MOSS - FERN
1. Establish a correspondence between the characteristic feature of the plant and the department to which it belongs: 1) Bryophytes, 2) Ferns
A) leafy plants with rhizoids
B) the presence of a modified shoot with adventitious roots
C) the presence of a large number of air cells
D) the predominance of the gametophyte over the sporophyte
D) the presence of herbaceous and woody forms
E) the presence of an overgrowth in the development cycle
Answer
2. Establish a correspondence between the signs of organisms and the departments for which they are characteristic: 1) Fern-like, 2) Bryophyte. Write down the numbers 1 and 2 in the order corresponding to the letters.
A) the presence of a growth in the life cycle
B) lack of roots
C) the predominance of the gametophyte in the life cycle
D) development of spores in a box
D) the location of sporangia on the underside of the leaf
E) development of protonema from spores
Answer
3. Establish a correspondence between the signs and departments of plants for which they are characteristic: 1) Bryophytes, 2) Ferns. Write down the numbers 1 and 2 in the order corresponding to the letters.
A) lack of roots
B) developed conducting system
C) the presence of aquifers
D) poorly developed mechanical tissue
D) the predominance of the sporophyte over the gametophyte
E) modified underground shoot - rhizome
Answer
4. Establish a correspondence between the signs and divisions of plants: 1) Bryophytes, 2) Ferns. Write down the numbers 1 and 2 in the order corresponding to the letters.
A) some have aquifers
B) sporophyte prevails over gametophyte
B) a sprout grows from a spore
D) spores develop in a box
D) there are no roots
E) there are complex leaves
Answer
5. Establish a correspondence between the sign of a plant and the systematic group for which it is characteristic: 1) Bryophytes, 2) Ferns
B) an adult plant - a sporophyte
B) spores are formed in boxes
D) spores are formed in sporangia on the underside of leaves
D) a sprout develops from a spore
E) a pregrowth (protonema) develops from the spore
Answer
6. Establish a correspondence between the reproduction feature and the plant department for which it is characteristic: 1) Bryophytes, 2) Ferns. Write the numbers 1 and 2 in the correct order.
A) the gametophyte predominates in the development cycle
B) the asexual generation of plants dominates in the development cycle
C) the formation of spores occurs in a box (sporogon)
D) the sporophyte is not capable of forming organic substances from inorganic
D) the gametophyte is represented by an outgrowth
E) the spore germinates into a pregrowth
Answer
SHAPING 7:
A) the formation of a box on the leg
B) development of adult gametophyte plants
C) development of an adult plant from a zygote
D) haploid set of chromosomes in the somatic cells of an adult plant
D) the location of sporangia on frond leaves
MOSSES LIKE FERN
Choose three options. Ferns, like mosses
1) are higher spore plants
2) have vegetative and generative organs (flowers, fruits)
3) are perennials
4) in the process of photosynthesis form organic substances from inorganic
5) do not need water during reproduction and development
6) do not contain chloroplasts and mitochondria in cells
Answer
MXI - GYMOSEMENS
1. Establish a correspondence between the trait of the plant and the department for which this trait is characteristic: 1) Gymnosperms, 2) Bryophytes. Write the numbers 1 and 2 in the correct order.
A) forms the tree layer of the forest
B) the presence of a tap root system
C) the predominance of the sporophyte in the development cycle
D) grows in the lower tier of the forest
E) the presence of a pregrowth (protonema) in the development cycle
E) attached to the soil by rhizoids
Answer
2. Establish a correspondence between the characteristics of life cycles and plant divisions: 1) Gymnosperms, 2) Bryophytes. Write down the numbers 1 and 2 in the order corresponding to the letters.
A) endosperm formation
B) the predominance of the gametophyte over the sporophyte
C) the formation of a pregrowth (protonema)
D) the participation of water during fertilization
D) maturation of pollen on the sporophyte
Answer
3. Establish a correspondence between the signs and divisions of plants: 1) Bryophytes, 2) Gymnosperms. Write down the numbers 1 and 2 in the order corresponding to the letters.
A) reproduction is not associated with water
B) reproduce by means of spores
B) the presence of rhizoids
D) the gametophyte dominates the sporophyte
E) representatives of the department are cuckoo flax and sphagnum
E) representatives of the department are larch, cypress and juniper
Answer
MOSS - FLOWERS
1. Establish a correspondence between the signs and plant divisions for which they are characteristic: 1) Bryophytes, 2) Angiosperms. Write down the numbers 1 and 2 in the order corresponding to the letters.
A) the adult form is represented by a sporophyte
B) the gametophyte predominates in the development cycle
B) there are no roots
D) plants have a flower and a fruit
D) pollination occurs with the help of wind and insects
E) spores develop in a box
Answer
2. Establish a correspondence between the sign of the plant and the department for which it is characteristic: 1) Mosses, 2) Angiosperms. Write down the numbers 1 and 2 in the order corresponding to the letters.
A) propagated by seeds
B) the presence of rhizoids
B) the presence of flowers
D) the presence of roots
D) there are no conductive tissues
E) the gametophyte predominates in the life cycle
Answer
MHI EXC. FROM FLOWERS
Choose three options. Mosses, unlike angiosperms,
1) form sex cells
2) do not have tissues
3) have rhizoids
4) are phototrophs
5) reproduce by spores
6) do not have a flower
Answer
FERN IN EXC. FROM MOSS
Choose three correct answers from six and write down the numbers under which they are indicated. For ferns, unlike mosses, it is characteristic.
1) the presence of a growth
2) the formation of rhizoids in the sporophyte
4) the presence of roots
5) reproduction by spores
6) predominance in the life cycle of the sporophyte
Answer
FERN - Gymnosperms
1. Establish a correspondence between processes and plant divisions: 1) gymnosperms, 2) ferns. Write the numbers 1 and 2 in the correct order.
A) endosperm formation
B) the formation of a green growth
B) fusion of immobile gametes
D) development of the pollen tube
D) reproduction and settlement by spores
Answer
2. Establish a correspondence between the feature of the plant and the department for which it is characteristic: 1) Ferns, 2) Gymnosperms. Write the numbers 1 and 2 in the correct order.
A) The eggs develop in the gametophyte on the scales of the cones.
B) A pollen grain develops from a spore.
C) There is a haploid outgrowth in the development cycle.
D) Life form - shrub or tree.
D) Adventitious roots develop from the rhizome.
E) Spores develop in sporangia on leaves.
Answer
3. Establish a correspondence between the signs and departments of plants for which they are characteristic: 1) Ferns, 2) Gymnosperms. Write down the numbers 1 and 2 in the order corresponding to the letters.
A) the presence of an overgrowth in the development cycle
B) reproduction by spores
B) the presence of ovules
D) the presence of sperm
D) development of the main root
E) the presence of tree and herbaceous forms
Answer
FERN - FLOWER
1. Establish a correspondence between the sign of a plant and the department to which it belongs: 1) Ferns, 2) Angiosperms
A) fruit development
B) the sexual generation is represented by an outgrowth
B) reproduction by spores
D) the process of fertilization depends on the availability of water
D) the presence of a flower
E) double fertilization
Answer
2. Establish a correspondence between the features of plant development and the departments for which they are characteristic: 1) Fern-like, 2) Flowering. Write down the numbers 1 and 2 in the order corresponding to the letters.
A) reproduction by spores
B) the formation of male and female germ cells on the outgrowth
C) pollinated by wind and insects
D) double fertilization
D) the formation of seeds inside the fruit
E) the formation of spores on the lower surface of the leaves
Answer
3. Establish a correspondence between the signs and departments of plants for which they are characteristic: 1) Flowering, 2) Fern-like. Write down the numbers 1 and 2 in the order corresponding to the letters.
a) Plants reproduce by spores.
B) There is a growth in the development cycle.
C) The seeds are protected by the pericarp.
D) Plants have both taproot and fibrous root systems.
D) Fertilization occurs in the presence of water.
E) Pollination precedes fertilization.
Answer
4. Establish a correspondence between the signs and divisions of plants: 1) Flowering, 2) Fern-like. Write down the numbers 1 and 2 in the order corresponding to the letters.
A) growth development
B) reduction of the gametophyte to several cells
B) dispersal by spores
D) fertilization in the presence of water
D) the implementation of pollination and fertilization
E) development of the embryo sac in the ovule
Answer
Gymnosperms - FLOWERS
1. Establish a correspondence between the fertilization feature and the department of plants for which it is characteristic: 1) angiosperms, 2) gymnosperms
A) two sperm are involved
B) one sperm is involved
C) triploid endosperm is formed
D) eggs develop in female cones
E) sperm fuses with the central diploid cell of the embryo sac
Answer
2. Establish a correspondence between the department of plants and the characteristics of the sporophyte of its representatives: 1) Gymnosperms, 2) Angiosperms. Write down the numbers 1 and 2 in the order corresponding to the letters.
A) life form - mostly trees
B) life form - grasses, shrubs, trees
C) there are special organs for vegetative reproduction
D) there are no special organs for vegetative reproduction
D) xylem is represented by vessels
E) xylem is represented by tracheids
Answer
3. Establish a correspondence between the signs and plant divisions for which they are characteristic: 1) Gymnosperms, 2) Angiosperms. Write down the numbers 1 and 2 in the order corresponding to the letters.
A) represented by all life forms
B) pollinated by the wind
B) have a variety of inflorescences
D) the presence of seeds in cones
E) the presence of triploid endosperm in the seed
E) have no fruit
Answer
FLOWER EXC. FROM GYM
1. Choose three correct answers from six and write down the numbers under which they are indicated. Angiosperms, unlike gymnosperms:
1) Capable of forming extensive forests
2) Characterized by a variety of life forms
3) Propagated by seeds
4) Pollinated by insects and birds
5) Have well-developed vegetative organs
6) Form juicy and dry fruits
Answer
2. Choose three correct answers from six and write down the numbers under which they are indicated. Angiosperms, unlike gymnosperms,
1) are perennial plants
2) contain chloroplasts with chlorophyll
3) have flowers and inflorescences
4) form fruits with seeds
5) represented by three life forms
6) propagate by seeds
Answer
Choose one, the most correct option. In the process of evolution, the stem with leaves first appeared in
1) algae
2) mossy
3) ferns
4) Lycopsoid
Answer
Establish the sequence of stages of individual development of an annual angiosperm plant from seed
1) the formation of fruits and seeds
2) the appearance of vegetative organs
3) the appearance of flowers, pollination
4) fertilization and embryo formation
5) seed germination
Answer
Choose three options. What is the function of a plant flower?
1) pollination
2) absorption of substances
3) fertilization
4) vegetative propagation
5) deposition of spare substances
6) the formation of seeds and fruits
Answer
Choose one, the most correct option. What characterizes the group of mosses in comparison with other groups of plants
1) in the process of development there is an alternation of generations
2) reproduce by spores
3) have leaves, stem and rhizoids
4) form organic substances during photosynthesis
Answer
Choose three options. Seeds propagate
1) white cabbage
2) creeping clover
3) club moss
4) deer moss
5) horsetail
6) onion
Answer
Choose two of the plants listed below that reproduce by spores, and write down the numbers under which they are indicated.
1) bracken fern
2) horsetail
3) beautiful clover
4) rocky juniper
5) couch grass
Answer
Choose three correct answers from six and write down the numbers under which they are indicated. What allowed angiosperms, in comparison with gymnosperms, to occupy a dominant position on Earth?
1) the location of the seeds inside the fruit
2) the presence of chloroplasts in cells
3) symbiosis with bacteria and fungi
4) the presence of a flower
5) double fertilization
6) propagation by seeds
Answer
1. Choose three correct answers out of six and write them down in the numbers under which they are indicated. What are the characteristics of the plant shown in the picture?
1) sporophyte predominates in the development cycle
2) the gametophyte is represented by an outgrowth
3) has modified leaves
4) the seeds are not protected by the pericarp
5) forms fruits
6) pollination is carried out by insects
Answer
2. Choose three correct answers from six and write down the numbers under which they are indicated. If the plant has formed shoots shown in the figure, then this plant is characterized
1) fertilization with water
2) deposition of organic matter in the rhizome
3) propagation by seeds
4) predominance in the life cycle of the sporophyte
5) the presence of a dry multi-seeded fruit
6) well-developed tracheids in wood
Answer
Choose three correct answers from six and write down the numbers under which they are indicated. The plants shown in the figure are characterized by the following features
1) lower plants
2) primitive higher spore plants
3) diploid sporophyte prevails over haploid gametophyte
4) no roots
5) the body is not divided into tissues and organs
6) haploid gametophyte prevails over diploid sporophyte
Answer
Choose three correct answers from six and write down the numbers under which they are indicated. If in the process of evolution a plant has formed a shoot shown in the figure, then this plant is characterized by
1) small scaly leaves
2) fertilization with water
3) propagation by seeds
4) the formation of fruits at the top of the shoot
5) development of a leafy plant from a protonema (pre-germ)
6) the presence of a well-developed root system
Answer
Choose three correct answers from six and write down the numbers under which they are indicated. The following plants are characteristic of a broad-leaved forest:
1) spruce
2) linden
3) Scotch pine
4) oak
5) beech
6) fir
Answer
Establish a correspondence between examples and categories of plants: 1) lower plants, 2) higher plants. Write down the numbers 1 and 2 in the order corresponding to the letters.
A) horsetail
B) lichens
B) real algae
D) lycopsform
D) mossy
E) purple
Answer
Choose three correct answers from six and write down the numbers under which they are indicated in the table. Plants that do not have roots are
1) cuckoo flax
2) male shield
3) club moss
4) horsetail
5) sphagnum
6) kelp
Answer
Choose three correct answers from six and write down the numbers under which they are indicated. What plants have roots?
1) clubs
2) brown algae
3) green mosses
4) sphagnum mosses
5) horsetail
6) gymnosperms
Answer
1. Choose three correct answers out of six and write down the numbers under which they are indicated in the table. Angiosperms are characterized
1) the presence of a growth
2) double fertilization
3) maturation of spores in spore-bearing spikelets
4) the presence of a fetus
5) triploid endosperm
6) predominance in the life cycle of the gametophyte
Answer
2. Choose three correct answers from six and write down the numbers under which they are indicated. In the process of reproduction and development of angiosperms,
1) pollen formation
2) the formation of an ovule in the ovary of the pistil
3) formation of a growth with rhizoids
4) double fertilization
5) formation of haploid endosperm
6) settlement with the help of spores
Answer
Establish a correspondence between the characteristics and the group of higher plants: 1) spore, 2) seed. Write down the numbers 1 and 2 in the order corresponding to the letters.
A) develop from the embryo
B) are more ancient in historical origin
B) have a taproot or fibrous root system
D) fertilize in the presence of water
D) form the embryo sac and pollen
Answer
Establish a correspondence between the signs and groups of plants: 1) lower, 2) higher. Write down the numbers 1 and 2 in the order corresponding to the letters.
A) the body is a thallus, or thallus
B) have vegetative and generative organs
B) have a light-sensitive eye
D) have a variety of tissues
D) live mainly in the aquatic environment
E) include unicellular organisms
Answer
Establish a correspondence between the characteristics and departments of plants. Write down the numbers 1 and 2 in the order corresponding to the letters.
A) a protonema is formed from a germinating spore
B) the gametophyte is reduced to a tiny outgrowth
B) have a rhizome with adventitious roots
D) the gametophyte predominates in the life cycle
D) spores mature in sporangia collected in sori
E) have a variety of life forms
Answer
Establish a correspondence between the characteristics and representatives of the plants shown in the figure. Write down the numbers 1 and 2 in the order corresponding to the letters.
A) the organism is attached to the substrate
B) the body is represented by a thallus
C) cells contain a variety of plastids
D) seed reproduction is characteristic
D) have vegetative and generative organs
E) forms a wintering zygospore
Answer
All of the characteristics below, except for two, are used to describe the plant depicted in the figure. Identify two terms that "fall out" from the general list, and write down the numbers under which they are indicated.
1) attached by rhizoids
2) a green plant is represented by a gametophyte
3) has a strobilus on the spring shoot
4) reproduces by spores
5) has a branched rhizome
Answer
Choose three correct answers from six and write down the numbers under which they are indicated. What signs are characteristic of the department to which the plant shown in the figure belongs?
1) double fertilization
2) predominance in the sporophyte development cycle
3) gametophyte reduction
4) straw stalk
5) complex spike inflorescence
6) intercalary growth
Answer
Choose three correct answers from six and write down the numbers under which they are indicated. Algae belong to the plant kingdom because
1) in ecosystems are producers
2) they carry out photosynthesis
3) in ecosystems they are consumers
4) their cells contain plastids
5) their body is not differentiated into tissues
6) they absorb oxygen for breathing
Answer
Analyze the text "Moss". For each cell marked with a letter, select the appropriate term from the list provided. Mosses are ________ (A) plants, because they reproduce by spores that form in special organs - ________ (B). In our forests, there are green mosses, such as cuckoo flax, and white mosses, such as ________ (B). Water is extremely important for the life of mosses, so they are often found near forest stagnant reservoirs: lakes and swamps. Centuries-old deposits of mosses in swamps form deposits of ________ (D) - valuable fertilizer and fuel.
1) inferior
2) box
3) seed
4) sorus
5) spore
6) sphagnum
7) peat
8) flower
Answer
© D.V. Pozdnyakov, 2009-2019
On earth there are representatives of the plant world, which are considered the largest. These are various types of mosses and lichens. Almost any of their varieties are used in the manufacture of medicines. Some are even used in construction due to their low thermal conductivity. The special science of bryology, which deals with the study of bryophytes, has also been singled out.
In nature, there are about 20 thousand species of mosses. Sphagnum species
Sphagnum is one of the most famous mosses in Russia. It grows in swamps. The lower region is dry and yellow in color, while the upper zone is green and moist. This is observed due to insufficient supply of oxygen and mineral compounds. A certain part of the plant eventually dies off, turns into peat. It is used to make fuel.
Which plants are to the mosses of the sphagnum group:
- Baltic;
- protruding;
- coastal;
- slotted.
Sphagnum has many uses Any variety of sphagnum moss is characterized by many useful qualities. With it, you can disinfect wounds, disinfect purulent surfaces. Dressings with gauze and sphagnum are applied to burns. It can be used during limb immobilization to prevent the dressing from rubbing against the skin. At the same time, the plant provides a moisturizing effect.
The plant is characterized by antifungal properties. The insoles for footwear made on its basis reduce sweating. Sphagnum absorbs liquid well. It is known that it can absorb water 20 times its own weight. It could be used in the fight against bleeding instead of cotton due to this property. In addition, it does not interfere with the breathing of the skin, does not form crusts.
Sphagnum finds application in the construction of wooden houses. It is used to seal joints between logs, ensuring a stable room temperature. He is also good at building baths.
The soil due to this technique will become more fertile. You can also put sphagnum at the bottom of the flower pot, soaking it with water: this way you can leave the plant for a long time without watering.
Liver varieties
This is a separate group of moss plants, uniting several subspecies. They got their own name due to the characteristic shape resembling the liver. Plants live in the subtropics and tropics, usually they have long leaves and stems. In addition, they also form the oldest family of mosses. Its most famous representative is blepharostomy hairy. It has a flat shape.
Liver mosses are usually found on deadwood, stones, stumps, along the banks of reservoirs. They form loose and dense layers. A separate category is bryophytes. They are divided into several groups according to the appearance of the leaves, stems and method of fixing in the ground. Plants form dense layers ranging in height from a few millimeters to 3 cm. Sometimes they cover vast territories.
Pellia liver moss can be grown in an aquarium One of the most beautiful representatives of the liver moss family. It is quite rare and grows in the swampy areas of China and Thailand. You can grow it at home, but you need an aquarium. Moss is able to grow on stone, sand and wood. It does not have special villi that allow it to hold firmly on the surface, so it is better to fix the plants with thread or fishing line.
When the colony grows, it will independently support itself and provide everything necessary. Pellia stems are quite fragile, so you should not place it in those places where herbivorous fish live. In general, with the right care, pella can turn into an excellent decoration for an aquarium.
Liverworts reproduce both sexually and asexually. In appearance, representatives of this group can differ significantly from each other, since this includes a large number of mosses and lichens.
This category includes 10,000 species of mosses. Kukushkin flax is its classic representative. You can find it in almost any forest. The plant resembles a miniature tree with a large number of pointed leaves. In suitable habitat conditions, it can form large colonies and grow to impressive sizes. If you place cuckoo flax in the garden, in the future it will take a long time to get rid of it.
When moss begins to bloom, a seed pod forms at the top of the stem. As it matures, it opens, and the wind spreads the seeds. Foresters consider this plant a pest due to the fact that it can grow intensively in conditions of good lighting and soil moisture.
Kukushkin flax belongs to the leafy species of moss In appearance, representatives of this class resemble liverworts. The description of leafy moss is as follows: a lamellar rosette of dark green color, tightly adhering to the ground and reaching a diameter of up to 3 cm. It contains horn-shaped outgrowths up to 3 cm high, presented in large numbers.
In addition to cuckoo flax, the class unites several more classical representatives. Their list includes:
- Hypnum cypress. It lives in the forest and covers large areas. Sometimes it settles on the roofs and walls of houses. Its stems are elongated.
- Wall tortula. It grows on limestones, walls of buildings and forms miniature pads from which long stems are drawn.
Another variety of leafy mosses is Polytrichum juniper-like - Polytrichum juniper-like. Its spore boxes resemble flowers.
- Cirriphyllum hairy. Forms light green sods. Prefers soil rich in limestone. You can find it in bushes, forests. It can also be planted in the backyard.
- The chylocomium is brilliant. It is found quite often in forests. During intensive growth, it forms cascades, which are, as it were, divided into several floors.
- Anthoceros is smooth. Lives in northern latitudes. Usually this species appears first after the spring thaw.
Subclass Andreeves
These plants prefer cold areas with temperatures around -5°C. They have straight small and stiff leaves. Due to thin villi, mosses penetrate into the structure of the stone and take root in it. In total, there are approximately 100 representatives of this class. The most famous of them are dicranum centipede and rodobrium rosette-shaped.
Rhodobrium rosette-shaped one of 100 species of mosses of subclass Andreevy In Russia, only 10 species are found that reproduce in a decorative way. They outwardly clearly differ from green mosses and sphagnum. The mechanism of their formation is as follows.:
- Colorless spores appear, which later germinate.
- Cell division occurs under the membrane. Tuberous bodies are formed, consisting of many cells.
- A green ribbon-like protonema is formed.
The leaves of such plants are single-layered, consisting of colorless hairs with increased absorbency. They absorb moisture from the air. There are no vascular bundles on the stem.
oak and plain
Oak moss is isolated in a separate species. It has a soft bushy thallus. It prefers northern and temperate latitudes, grows in mountain forests, takes root on the trunks of pine, oak, spruce and fir. Thallus can change shade depending on weather conditions. In dry times, it usually has a bright yellow or dark red tone. As soon as the summer heat sets in, the color of the plant changes to pale blue or white.
Depending on the season and weather conditions, oakmoss changes color It is noteworthy that this moss has strong allergenic properties. Despite this, it is used in small quantities in the production of perfumes. This is due to its original tart smell of needles. In folk medicine, oak moss is also highly valued. A tincture is prepared from it, which is effective against many diseases.
Common moss is found in Asia and Europe, North America and Africa. It prefers stagnant waters, but can also be found in moving waters. It has thin branched stems 40-50 cm long. The leaves are pointed, deep green, up to 1 cm long.
habitats
Mosses feel best on rocks and stones. Here they do not have to compete with flowering plants - the latter are simply not able to survive in such conditions. If there is a reservoir nearby, then high humidity also contributes to their harmonious growth.
Wetlands are common habitats for mosses Moss tissue contains a special type of cells that can retain water for a long time. With a long absence of precipitation, plants go into a dormant state. They reduce their own metabolism and change color. However, it is enough for them to get just a few drops of moisture to return to their usual life.
Tortula wall prefers sunny and dry places Most often you can see moss in damp shady places. But there are species that have adapted to dry and sunny areas. An example is a wall tortula. She has transparent hairs on her leaves that protect plants from heat. These plants have other ways to survive. For example, sphagnum can form an acidic environment, which repels bacteria, fungi, and competing plants that can displace it. And antoceros prefer to live in symbiosis with blue algae. The latter produce nitrogen and give it to their "neighbor".
Although moss is rather inconspicuous in appearance, it plays a very significant role in the ecosystem. These plants are able to retain a lot of moisture, which favorably affects the water balance of the swampy area. In open spaces, this feature contributes to the reduction of soil erosion. In addition, without sphagnum, the formation of peat mined in swamps is impossible. Plants form a dense green carpet, which serves as a favorable habitat for small animals and many insects.
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 systematize knowledge, I suggest filling out the following table:
Subject: Bryophytes. Moss characteristics.
Purpose: 1. To introduce students to the characteristic features of higher plants using mosses as an example. 2. Show features of complication in the organization of mosses (compared to algae).
Equipment: live plants or herbarium specimens of cuckoo flax, sphagnum or other mosses; microscopes; tables.
instruction card.
1. Consider the external structure of the moss. Find the stem and leaves. Indicate the shape, location, size and color of the leaves, the nature of the stem (branched, not branched).
2. Examine the top of the stem and find the spore box. Establish the importance of spores in plant life.
3. Examine a leaf of moss under a microscope and draw it in a notebook, sign the names of the main parts of the leaf.
4. Answer the questions: how do mosses differ from algae and flowering plants in structure? What are the similarities and differences in the nutrition of mosses and flowering plants?
2. Physiological characteristics of plants
Topic: Cellular structure of the root.
Purpose: To study the features of the external and internal cellular structure of the root.
Equipment: Sprouted bulbs of onions with water, sprouts of radish, lettuce, wheat, coverslips and glass slides, a glass of water, a dissecting needle, micropreparations of the root cap, root hairs, absorbing area.
instruction card.
1. Examine the roots of onions with the naked eye and with a magnifying glass. Find a root cap. Examine the micropreparation of the root cap under a microscope. Draw the cellular structure of the cap. Label its parts.
2. Find areas with root hairs on the roots of radish, wheat, lettuce. Mark their location on the root. Draw the root and root hairs. Label each section of the root.
3. Examine it with a microscope. Find a root hair and examine it. Sketch the root hair and label all its parts. Why has the shape of the cell changed?
4. Consider a transverse section of the conductive section of the root. Locate root vessels. Sketch the cellular structure of this section of the root. Locate root vessels. Sketch the cellular structure of this section of the root.
5. Compare the internal structure of the fruits of tomato and watermelon and the structure of the root. Find similarities and differences. How to explain the features of plant tissues of the root, draw a conclusion.
Topic: The structure of the stem.
Purpose: To study the internal structure of the stem on the example of coniferous and deciduous trees.
Equipment: parts of tree stems, dissecting needles, an album.
instruction card.
1. Consider the transverse and longitudinal sections of the branches and find the layers of the stem of a woody plant.
2. On the longitudinal section of the branch, separate the bark, determine the property of the wood surface by touch, find an explanation of this property in the text of the textbook.
3. Examine the structure of the bark, wood and core with a magnifying glass. With a dissecting needle, select parts of the bark (cork and bast fibers), wood and core. Place them in the laboratory place and write the names of each of these parts.
4. Design the application “Structure of a woody plant”, draw a longitudinal section of a branch in a notebook and sign the name of each layer, using the appropriate text and drawing from the textbook.
Subject: Modified shoots.
Purpose: To investigate the shoots of potato tubers in connection with their functions.
Equipment: potato tubers, scalpel, album.
We begin to acquaint students with modified shoots during a conversation about the importance of potatoes (food, fodder and industrial crops). In order to update the knowledge previously acquired by students about the organs of a flowering plant, we propose for discussion the question: can a potato tuber be called a root, leaf, flower, fruit? As a result, a problematic situation is created (what is a potato tuber?) and the need to solve an educational problem, during which students must refute erroneous assumptions and prove that a potato tuber is a modified shoot.
The solution to this problem is carried out in the following sequence: students list the signs of the fruit and the shoot, find out which of these signs are inherent in the tuber, and conclude that the tuber is a modified shoot. They are convinced of this in the course of laboratory work involving the study of the external and internal structure of the tuber. Carrying out work on the instruction card.
instruction card.
1. Examine the tuber, find the buds. Draw the outline of the tuber and mark the eyes and the kidneys located in them.
2. Remember how the kidneys are located on the tuber.
3. Count the number of eyes on the tuber; more of them are located at the top, less - at the base; determine where the tuber has the top, where is the base.
4. Examine thin transverse sections of a potato tuber to the light and find parts of the stem; draw the structure of a cross section of a potato tuber; prepare an answer to the question: why do peeled new potatoes slide in your hands?
5. Compare the internal structure of the linden stem and the internal structure of the tuber; explain the differences.
Topic: The movement of water through the plant
Purpose: To get acquainted with the principle of water flow to the leaves and buds of a plant.
Equipment: cross sections of tree species of plants, albums.
The study of the question of the movement of water and minerals along the stem begins with a repetition of the material on the root, the flow of water and minerals into the plant, the relationship between the structure and function of the root. We talk about the structure and functions of the leaf and invite students to answer the question: on which part of the stem does water rise to the leaves?
We conclude the discussion of this topic with a demonstration of an experiment proving that water and mineral salts move along the stem wood, and I invite students to study the results of this experiment, guided by an instruction card when doing laboratory work.
instruction card.
1. Consider the transverse and longitudinal sections of linden branches placed in tinted water.
2. Sketch them, sign the names of the layers, use a colored pencil to depict the results of the experiment.
3. Explain why the wood was stained, and not the core and bark.
3. Ecological features of plants.
Topic: "The variety of inflorescences of flowering plants."
Purpose: 1. To get acquainted with the structure of simple and complex inflorescences. Learn to recognize the types of inflorescences.
In this lesson, we get acquainted with the variety of inflorescences in connection with the attraction of insects for pollination.
Mosses are among the higher plants. However, this is the most ancient and simply organized group. At the same time, bryophytes are very diverse and numerous and are inferior in number of species only to flowering plants. There are about 25 thousand species of mosses.
The vast majority of mosses are perennial plants, their height is from a few millimeters to 20 cm. Mosses grow only in well-moistened areas.
Mosses have a semblance of roots - rhizoids that absorb water and fix the plant in the soil. In addition to the main and photosynthetic tissue, mosses do not have other tissues.
So mosses do not have integumentary, mechanical, conductive and storage tissues.
Department Mosses (Bryophytes) is divided into two classes - Liver mosses and Leafy mosses.
Liverworts are the most ancient mosses. Their body is represented by a branched flat thallus. There are many liverworts in the tropics. Marchantia moss grows in damp places that are not overgrown with grass. Marchantia has a creeping thallus that looks like a leaf blade. In the upper part of its thallus there is a photosynthetic tissue, in the lower part - the main one. Another representative of mosses is Riccia.
In leafy mosses, the body has shoots consisting of stems and leaves. A typical representative is the cuckoo flax, which is often found in coniferous forests and tundra, near sphagnum bogs and in damp places. It is a plant more than 10 cm tall.
Mosses have asexual and sexual reproduction. Asexual reproduction is represented both by vegetative reproduction, when the plant reproduces by parts of the thallus, stems or leaves, and by spore reproduction.
During sexual reproduction, mosses grow special organs in the upper part of the body. They form gametes - mobile spermatozoa and immobile eggs. The spermatozoa move along the water to the egg and fertilize it. After fertilization, the so-called box with spores grows on the plant. After maturation, the spores disintegrate and spread over long distances.
The spore, once in a favorable environment, develops into a multicellular green thread protonema, on which thalli or shoots then grow.
Kukushkin flax can lead to waterlogging of the soil, as it creates dense covers on the soil, which leads to the accumulation of water. Where the cuckoo flax grows, another representative of the moss may appear - sphagnum (white moss). In its leaves, cells with chlorophyll alternate with large cells containing air and water. Sphagnum can quickly accumulate water in the body and further contribute to the waterlogging of the soil. The dead parts of sphagnum are part of peat.
Biology
5th grade
§ 20. Mosses
- What are rhizoids?
- Why are algae classified as lower plants?
- What is a dispute?
Mosses are distributed mainly in well-moistened places and only occasionally in arid areas (during the dry period they are at rest and resume their vital activity when precipitation falls).
Unlike algae, mosses have a stem and leaves, with the exception of a number of species of primitive liver mosses, in which the body is represented by a thallus. Mosses do not have real roots, they are replaced by rhizoids, with which they strengthen themselves in the soil and absorb water.
Since the body of mosses is divided into stems and leaves, and they reproduce by spores, they are classified as higher spore plants.
There are hepatic and leafy mosses.
liver mosses. Those who have an aquarium at home are well aware of the floating plant that covers the surface of the water with a green carpet. This is one of the liver mosses - Riccia (Fig. 68). Its body consists of a forked branched thallus. In good light, Riccia grows rapidly, forming dense cushions on the surface of the water.
Rice. 68. Liver mosses
Floating Riccia does not have rhizoids, but when water bodies dry up, remaining on damp soil, it can form them. Various types of liver mosses are found in damp forests, swamps, and reservoirs.
Leafy mosses. One of the most famous leafy green mosses is cuckoo flax (Fig. 69), it can often be found in swampy or simply wet places. Its slender brownish stems are covered with small dark green leaves and look like miniature flax plants.
Mosses - ancient and important
69. Moss cuckoo flax
Cuckoo flax has male and female plants. At the tops of male plants are the reproductive organs, in which mobile sex cells (gametes) develop - spermatozoa (from the Greek words "sperm" - seed, "zoon" - a living being and "eidos" - species).
In female plants, the genital organs are located at the tops with the female reproductive cell (gamete) - the egg.
On female plants, boxes on long legs develop, covered with hairy pointed caps. They look like a sitting cuckoo. Hence the name of the moss - cuckoo flax. Spores develop in the boxes. Spilling out and germinating, they form new moss plants.
Kukushkin flax is a perennial plant. Covering the soil in damp places with a continuous carpet, it often crowds out other green mosses.
moss structure
- Consider a moss plant. Determine the features of its external structure, find the stem and leaves.
- Determine the shape, location, size and color of the leaves. Examine the leaf under a microscope and draw it.
- Determine if the plant has a branched or unbranched stem.
- Examine the tops of the stem, find male and female plants.
- Examine the spore box. What is the importance of spores in the life of mosses?
- Compare the structure of moss with that of algae. What are their similarities and differences?
- Write down your answers to the questions.
The representative of white, or sphagnum, mosses is sphagnum.
Sphagnum is a plant with a strongly branching stem (Fig. 70). Unlike cuckoo flax and other green mosses, it does not have rhizoids. The stem and branches of most sphagnum species are covered with small light green leaves. Each leaf consists of one layer of cells. These two different types of cells, their differences are clearly visible under a microscope.
Rice. 70. Moss sphagnum
Narrow green cells containing chloroplasts are connected to each other and form a continuous network. Organic substances are formed in these cells, which come from the leaves to the stem.
Between the green cells are other, larger ones. Their cytoplasm is destroyed, only shells with holes are preserved, so these dead cells are transparent and can be filled with water or air. Up to 2/3 of the leaf surface consists of these cells. Thanks to this structure, sphagnum quickly absorbs and conducts water.
Outside, the stems are also covered with transparent dead cells. Dead cells of sphagnum leaves and stems are able to absorb water 20-25 times their mass, hold it for a long time, gradually giving it to living cells.
Usually sphagnum grows on raised bogs, covering the surface of the soil with a continuous carpet, but it can also grow under the forest canopy among cuckoo flax. Where sphagnum settled, the soils are waterlogged. On excessively moist soil, trees grow poorly, become oppressed, and sphagnum, on the contrary, grows into a lush carpet, and the forest gradually becomes swampy.
Sphagnum reproduces by spores, just like cuckoo flax and other mosses. At the ends of the upper branches, it forms small boxes in which spores ripen.
The value of mosses in nature and human life. Mosses, settling in meadows, in forests, cover the soil with a continuous carpet, making it difficult for air to enter.
This leads to acidification and waterlogging of the soil.
Leaf-stemmed, especially sphagnum, mosses cover swamps with a continuous carpet and, dying, form peat, which is widely used by humans. Peat is used as a fuel, fertilizer and as a raw material for industry. Wood alcohol, carbolic acid, plastics, insulating tapes, resins and many other valuable materials are obtained from peat.
New concepts
Moss. Spore. Higher spore plant. Sperm. Egg
Questions
- Why are mosses called higher spore plants?
- What is the structure of cuckoo flax?
- How is sphagnum different from cuckoo flax?
- How is moss different from algae?
- What is the importance of mosses in nature and human life?
Think
Why don't even the largest mosses reach sizes over 80 cm?
Quests for the curious
- Examine the leaves of sphagnum moss under a microscope. Note the structural features of the two types of cells of which they are composed.
- Place some Riccia in a jar of damp soil. Cover the jar with glass and place in a warm, bright place. Make sure the soil is constantly moist. Watch what happens with Riccia.
Do you know that…
- Stumps and roots of trees, leaves and pollen of plants that lived millennia ago are preserved in peat layers. They are not completely destroyed, since there is little oxygen in the peat layer, in addition, sphagnum secretes substances that prevent the development of bacteria. When draining and developing swamps, well-preserved old boats, the remains of animals and people who died in the swamp, are sometimes found in the thickness of peat.
- Sphagnum was widely used during the war years as a substitute for cotton wool due to its high moisture capacity and good bactericidal properties.
Mosses are a group of higher plants. They are distinguished by such a complex structure and diversity that a whole science has been formed, which studies them - bryology.
Despite the fact that bryophytes belong to higher plants, they have there are no roots and flowers, but they reproduce with the help of spores and vegetatively.
These plants are widespread everywhere - they can be found even in Antarctica, they are so unpretentious and resistant to any climate.
Mosses are undersized, perennial plants, from 1 mm to 60 cm high. They grow on trees, earth, stones, house walls, in fresh water bodies and in swamps.
Moss is one of the oldest plants on Earth. His age - about 300 million years.
moss species
First of all, it is necessary to distinguish between bryophytes and mosses proper. Modern science recognizes three classes of bryophytes:
- bryophytes;
- liverworts;
- anthocerotes.
Of these, only the first class belongs to real mosses. The remaining classes have recently been considered as independent botanical departments.
The largest class of bryophytes - leafy mosses. There are more than 14 thousand species of them, and they make up 95% of all bryophytes.
The name of this class reflects its appearance and structure - plants consist of stems with outgrowths covering them, leaves of various shapes, arranged in a spiral.
On the underground part of the stems, instead of roots, there are rhizoids - long filamentous outgrowths. With their help, the plant draws water and minerals from the soil.
Complex structure, unique reproduction process, ability to fall into a state of suspended animation helps mosses survive in any climatic conditions and play a leading role in many plant communities - in the tundra, mossy forests, etc.
The most famous subclass of leafy mosses is green. It includes, in particular, such an aquatic plant popular with aquarists as Java moss.
plant kingdom
With it, the aquarium becomes green and beautiful; the plant is easily attached, and aquarium fish like to spawn in its leaves.
About 1500 species of bryophytes live on the territory of Russia, of which the most common are:
- Kukushkin lyon. It is found in forests and meadows of central Russia, has a bright green color.
- Sphagnum, or peat moss. The main place of distribution is swamps, it is distinguished by a lighter color.
The difference between mosses and lichens and ferns
Moss is often confused with lichen. Examples: Icelandic moss and reindeer moss are actually lichens. Icelandic moss is known for its medicinal properties - it is used to treat tuberculosis, colds, and restore strength.
The difference between mosses and lichens is that lichens are of more ancient origin and are representatives of lower spore plants.
But ferns occupy a higher stage of evolution, and they have a vascular conducting system. Unites plants method of reproduction: both of them use spores for this, not seeds.
The value of moss
The importance of mosses in nature and human life is enormous. Bryophytes:
- Pioneers. They are the first to develop lands with adverse climatic conditions.
- Regulate the water balance in the soil.
- Sphagnum is a source of peat, a mineral used as fuel and fertilizer.
- They have disinfecting properties.
- Accumulate and retain radioactive substances.
- They are a food source for many animal species.
- Protect soil from erosion.
However, the spread of mosses can lead to waterlogging of agricultural land.
Mosses play a leading role in the formation of special natural complexes. For example, tundra.
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Bryophytes department, their classification, ecological features and indicator value.
Mosses do not have flowers, roots, or a conducting system. Mosses reproduce by spores that mature in sporangia on sporophytes. In the life cycle, unlike vascular plants, the haploid (that is, with a single set of unpaired chromosomes) gametophyte (sexual generation) predominates. The moss gametophyte is a perennial green plant, often with leaf-like lateral outgrowths and root-like outgrowths (rhizoids), while the sporophyte (or asexual stage of the life cycle) is short-lived, dries quickly and consists only of a stem and a box in which spores mature.
The moss sporophyte (named sporogony, or sporogon), has a simpler structure than other groups of higher plants. It is not able to take root and is located on the gametophyte. The sporophyte usually consists of three elements:
a box (or sporangium) in which spores develop;
The stem (or sporophore) on which the box is located;
feet, providing a physiological connection with the gametophyte.
In nature:
· Participate in the creation of special biocenoses, especially where the soil is almost completely covered (tundra).
Moss cover is able to accumulate and retain radioactive substances.
· They play an important role in regulating the water balance of landscapes, as they are able to absorb and retain large amounts of water.
In human activity:
· May impair the productivity of agricultural lands, contributing to their waterlogging.
· Protect the soil from erosion, providing a uniform transfer of surface water runoff into underground.
Some sphagnum mosses are used in medicine (as dressings if necessary).
· Sphagnum mosses are a source of peat formation.
MHI(bryophytes), department of higher plants. Includes 22–27 thousand species. Anthocerotus mosses are distinguished, liver mosses and leafy mosses. Known from the Carboniferous. Distributed everywhere.
How do mosses and ferns differ from flowering plants?
They are of particular importance in the tundra, where they play a landscape role. In the tropics, they are common high in the mountains, where a special belt of mossy forests is located. Most mosses are perennial stunted plants. They differ in a relatively simple internal organization (they have poorly expressed conductive, mechanical, storage and integumentary tissues). Mosses are devoid of roots, dissected into stems and leaves, or form a thallus (thallus) creeping along the ground. Monoecious, dioecious or polyecious plants. AT alternation of generations in mosses, the gametophyte (sexual generation) dominates. Along with ensuring sexual reproduction, it performs the main vegetative functions (photosynthesis, water supply, mineral nutrition). The sporophyte (asexual generation) is poorly developed, it is always connected with the gametophyte (they exist together on the same plant) and is never divided into stem and leaves.
The organs of sexual reproduction - antheridia (male) and archegonia (female) are more often located on the plant in groups, usually surrounded by leaf-shaped outgrowths or other protective formations. Fertilization of the egg by mobile two-flagellated spermatozoa, which are formed in the antheridia, is possible only in the presence of drip-liquid water. The fusion of gametes and the development of the zygote takes place inside the archegonium. From the zygote for a certain time (from several months to 2 years), a multicellular diploid sporophyte (a specialized reproductive organ), called sporogon, develops. It consists of the upper spore-bearing part (box) and the lower - legs with a foot growing into the tissue of the gametophyte. From the spores formed by reduction division, a multicellular branched filamentous or lamellar formation develops - a protonema, on which buds are laid, giving rise to lamellar thalli or leafy shoots - gametophores. The mass participation of mosses in the vegetation cover has a significant impact on the habitat of other plants and animals. In areas of increased moisture in temperate zones, significant (up to 11 m thick) peat deposits accumulate with a predominance of mosses.
Some mosses ( sphagnum) have antibiotic properties and are used in medicine.
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Variety of mosses. Their role in nature and human life
Variety of mosses. Bryophytes are common in all climatic zones of land. In our time, more than 25 thousand species of mosses are known (in Ukraine - about 800). These are predominantly perennial, rarely annual herbaceous plants. The green stems of individuals of the sexual generation in different species are from 1–2 mm to one meter long. Mosses grow on the surface of the soil almost everywhere - from swamps to deserts, some species have mastered fresh water. The largest number of species grows in well-moistened places - humid forests, meadows, etc. In swamps and tundra, mosses form the basis of plant communities. Often they settle on trees and rocks. Mosses growing in deserts can remain viable for several years, being in a dried state.
Over 300 species of the genus Sphagnum are distributed in swamps and other waterlogged places, mainly in the Northern Hemisphere. Sphagnum stems reach a height of 50 cm. Plants branch strongly at the top and are devoid of rhizoids. Leaves are made up of two types of cells: some are living and some are dead. Living cells are green and photosynthesis takes place in them. Dead cells are colorless, their membranes have pores through which they absorb water.
Among sphagnums, there are both monoecious and dioecious species. Sphagnums grow at the top, and the lower part of the stem gradually dies off. Dead parts of plants are immersed in water. Since there is usually little oxygen in swamp water, and sphagnum secretes acids that kill microorganisms, its dead parts do not rot. They settle at the bottom of the swamps for tens, hundreds and thousands of years, are compressed and form peat. Peat layers can sometimes reach several tens of meters in thickness. But the rate of peat formation is insignificant: in ten years, a layer no thicker than one centimeter is deposited.
The value of moss in nature and human life. Mosses are not demanding on growing conditions, they can settle where other plants are absent.
What is moss? Structure, reproduction, types of mosses, their meaning and application
By releasing acids, mosses cause the gradual destruction of rocks, and their dead parts accumulate between the debris. This is how primary soils arise, on which other plants settle over time. Interestingly, animals almost do not eat mosses. This contributes to the accumulation of their residues in the soil and, thus, to an increase in humus reserves.
A continuous layer of living mosses and their dead parts in the forests and tundra prevents the evaporation of water and contributes to its preservation in the soil. Often this leads to swamping, that is, the formation of swamps in places of forests and other plant communities. Wetlands play an exceptional role in maintaining the flow of rivers, since it is from them that streams and small rivers originate. But with an increase in the degree of waterlogging of the area, the area of arable land may decrease.
An important role in human economic activity is played by peat, the world reserves of which are estimated at 270 billion tons. Peat is used as organic fertilizer and fuel. In the form of pressed boards, it is used in construction as a heat-insulating material. In the chemical industry, peat serves as a raw material for the production of plastics, paints, varnishes, alcohols, acids, etc. Dried sphagnum has disinfecting (antibacterial) properties, so it was previously used for wound dressing.
In the mountains of Europe, in particular in the Carpathians, a special type of moss is found on rocks and in caves. The green thread growing from the spores of this moss lives for a long time, reaching a considerable size, and is capable of glowing in the semi-darkness. Special lenticular cells capture weak light and direct it to chloroplasts, creating conditions for photosynthesis. Light passing through the chloroplast is reflected by the cell wall as a green beam. The glow of this moss gave rise to folk legends about gnomes who guard treasures in caves with lanterns at night.
Water moss fontinalis, the sexual generation of which looks like branched creeping stems, is used by aquarists during the spawning of ornamental fish. Caviar, located among densely intertwined moss shoots, is reliably protected from being eaten by other inhabitants of the aquarium and from the action of harmful microorganisms, since moss releases special substances that kill them.
Bolls of different types of mosses contain from several tens to a million spores with a diameter of 5 to 200 microns. Moss spores do not lose their ability to germinate after staying for several hours at a temperature of -200 °C or short-term heating to +100 °C.
Flipping through the pages of biology:
Ferns
Lycopsids and horsetails
General characteristics of seed plants
Types of roots. Types of root systems
Root structure
The root is an organ that provides mineral nutrition to plants.
Root modifications and their functions
Escape and its structure. Escape development from the kidney
Biology (content)
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 round-shaped 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 are responsible 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.
