Department of gymnosperms presentation. Department of gymnosperms

The diversity of gymnosperms is considered using a multimedia presentation. Slide show depicting gymnosperms commented a little message. I consider it necessary to introduce students to gymnosperms growing not only in Russia, but also on the territory of other states.

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Features of the organization Seeds appear in gymnosperms. These are more perfect than spores, units of reproduction and settlement, since they have an embryo and reserve nutrients necessary at the first stages of its development. Dense shells protect the seed from adverse factors, many of which are detrimental to spores. Seed plants have acquired advantages in the struggle for existence, which determined their flourishing in the drying up of the climate.

Ancestors of gymnosperms: the oldest representatives of the ferns. It is among them that there are heterosporous tree-like forms with secondary wood, which could give rise to gymnosperms. Gymnosperms did not originate from true (typical) ferns, but from one of the lateral branches of the most ancient fern-like plants.

Gymnosperms have a stem, root and leaves. They form seeds by which they reproduce and spread. Gymnosperms are wind-pollinated plants, their reproduction does not depend on water. Due to this, seed plants are currently the conquerors of land. Gymnosperms in the bark and wood have resin channels filled with resin and essential oils. The needle-like or scaly leaves are covered with a tough cuticle. The stomata are embedded in the tissue, which reduces the evaporation of water.

The most common in Russia Spruce Pine

Juniper

Siberian and Dahurian larch

Fir and Siberian pine

Ephedra - undersized shrub

Cypress - the tree of the Mediterranean

Thuja grows there

Cryptomeria is loved by the Chinese and Japanese

Conifers of the southern hemisphere. Araucaria

Welwitschia from the Namib Desert

Liana gnetum

cycad

Ginkgo biloba

Consider pine and fir cones. Why are these plants called gymnosperms?

Male cones Female cones

The use of conifers Furniture, paper are made from coniferous wood; it is used in the construction of buildings, the manufacture of musical instruments, pencils. Coniferous resin is used to obtain rosin, turpentine. Coniferous fragrances are used in the manufacture of creams, shampoos, and soaps. Larch gives a person wood that does not rot in water and is not inferior in strength to metal.

These plants form vast forests (taiga), and also decorate streets and city parks. Less resistant to air pollution.

On the topic: methodological developments, presentations and notes

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General characteristics. The first gymnosperms appeared at the end of the Devonian period about 350 million years ago; they are probably descended from ancient ferns that became extinct at the beginning of the Carboniferous. IN mesozoic era- the era of mountain building, raising the continents And dry climate - the gymnosperms reached their peak, but already from the middle of the Cretaceous lost their dominant position to the angiosperms.

The department of modern gymnosperms includes more than 700 species. Despite the relatively small number of species, gymnosperms have conquered almost the entire Earth. In temperate latitudes northern hemisphere on vast expanses they form coniferous forests called taiga.

Modern gymnosperms are represented mainly by trees, much less often by shrubs and very rarely by lianas; herbaceous plants not among them. The leaves of gymnosperms differ significantly from other groups of plants not only in shape and size, but also in morphology and anatomy. In most species, they are acicular (needles) or scaly; in some representatives, they are large (for example, in the amazing Velvichia, their length reaches 2-3 m), pinnately dissected, bilobed, etc. The leaves are arranged singly, two or more in bunches.

In late spring or early summer, mature pollen is carried by the wind and falls on the ovule. Through the micropyle, pollen is drawn into the ovule, where it grows into the pollen tube, which penetrates to the archegonia. The two spermatozoa formed by this time travel through the pollen tube to the archegonium. Then one of the sperm merges with the egg, and the other dies. From a fertilized egg (zygote) a seed embryo is formed, and the ovule turns into a seed. Pine seeds ripen in the second year, spill out of the cones and, picked up by animals or the wind, are transported over considerable distances.

In terms of its importance in the biosphere and role in economic activity Human conifers take second place after angiosperms, far surpassing all other groups of higher plants.

They help solve huge water protection and landscape problems, serve as the most important source of wood, raw materials for obtaining rosin, turpentine, alcohol, balms, essential oils for the perfume industry, medicinal and other valuable substances. Some conifers are cultivated as ornamental (firs, arborvitae, cypresses, cedars, etc.). Seeds of a number of pines (Siberian, Korean, Italian) are eaten, oil is also obtained from them.

Representatives of other classes of gymnosperms (cycads, gnets, ginkgos) are much rarer and less known than conifers. However, almost all types of cycads are decorative and are widely popular with gardeners in many countries. Evergreen leafless low shrubs of ephedra (class of oppressive) serve as a source of raw materials for the production of the alkaloid ephedrine, which is used as a means of stimulating the central nervous system, as well as in the treatment of allergic diseases.

Source : ON THE. Lemeza L.V. Kamlyuk N.D. Lisov "Biology manual for applicants to universities"

The lesson was built for the 6th grade according to the textbook by V.V. Pasechnik.

Lesson form: combined, using critical thinking technology

Stage of training on this topic: basic

Type of activity: search and reproductive

In this topic, a new group of plants is introduced, the representatives of which reproduce in a new way, for students, with the help of seeds and have cones of different sexes.

In Russia, 25% of the total area is occupied by coniferous forests, so this topic is of particular importance. Also, these forests are cut down everywhere, so it is necessary to talk about their protection.

Messages are given in advance to two students: “Pine”, “Spruce”. Pupils are given in advance to learn poems about nature protection and F. Tyutchev, which are available in the plan - abstract. You can also draw a table in advance, in order to save time. At the end of the lesson plan, an appendix is ​​given that can be used in the lesson, showing the diversity. At all stages of the lesson, a presentation is used, which is available in the application.

Purpose: to acquaint students with the structural features of gymnosperms and their diversity.

• Find out which plants are gymnosperms.
• Show the difference between seed reproduction and reproduction by spores.
• Consider the variety of gymnosperms, their significance.
• To form the ability to highlight the main thing, draw conclusions, work with a textbook and additional material. Develop the skills of search work, observation, accuracy when performing laboratory work.
• Concern for the protection of nature. Aesthetic design of the lesson and notebooks.

Equipment: herbarium material, fir cones, pine cones, computer, multimedia, screen, handout: crossword puzzle, labyrinth

Planned result:

• Students should know:
• Features of the structure of gymnosperms
• The structure of needles and cones of gymnosperms
• The value and diversity of gymnosperms in nature and human life
• Students should be able to:
• Distinguish species coniferous plants
• Call characteristics gymnosperms.

Organizing time.

I. Testing knowledge on the topics covered

Today we are moving on to the study of new plants, the name of which you will recognize by solving this crossword puzzle. The crossword puzzle grid is distributed to each desk. Children work in pairs.

1. Living organisms that have characteristics of plants and animals. Allocated to a separate kingdom.
2. Body of multicellular lower plants
3. green plant pigment
4. Another name for fungus
5. The cell by which fungi and lower plants reproduce
6. moss sex cells
7. Mutually beneficial cohabitation of living organisms
8. moss group
9. An organism composed of algae and a fungus
10. The deepest seaweeds
11. The group of algae to which kelp belongs
12. All living organisms are made up of them.

II. Main part

This is the topic of our lesson (recording the topic)

Look at the title. What does it tell you?

Today you will learn: (tasks are shown on the slide and spoken out)

1. What plants belong to this group, their meaning.

3. Does seed propagation give these plants an advantage?

5. We will carry out laboratory work to identify individual types

Slideshow. The task is given: write down the plants that belong to this group. Title on slides. The poem is read by the teacher or student.

... Not what you think, nature:
Not a cast, not a soulless face -
It has a soul, it has freedom,
It has love, it has a language... (F. Tyutchev)

While watching, the teacher pronounces the meaning of plants. from wood coniferous trees make furniture, paper, musical instruments, pencils, used as firewood. Gum is used for rosin, turpentine. Coniferous fragrance is used for the manufacture of creams, shampoo, soap. Larch gives a person wood that does not rot in water and is not inferior in strength to metal. The piles of the Troyan bridge on the Danube, built of larch, have been preserved for almost two millennia. Phytoncides are produced that kill microbes.

1. What do plants have in common? (coniferous, evergreen).

The teacher adds: thuja, spruce, fir, yew, gnetums (lianas), that conifers grow only in northern latitudes, and in South America and Australia, there are gymnosperms that have scaly leaves, such as cypress, Ginkgo. Over 500 species.

A very old group. 150 million years ago they reached their dominance. The first were cycads, similar to a palm tree. The last paragraph of the textbook.

Among them there are champions. Long-livers: sequoia dendron - mammoth tree (6000 years), in California - spiny pines live 4600 years. The largest of them are proper names. In the trunk of the Tree-House (height 90 m, thickness 11 m) a dacha was equipped, a road was laid through the Tree-Tunel. It has been calculated that 25 wagons would be required to transport the General Sherman.

2. What is needles? Find the answer in the textbook (p. 75)

• Are these plants superior or inferior? Rationale.
• How do they reproduce?
• What is the advantage of seed propagation? Answer by yourself or find the answer in the textbook.
• How are the seeds. Showing cones (we lead to the answer that the seeds lie openly on the surface of the scales). The teacher adds that there are male and female cones. There is no flower.

Primary consolidation of knowledge.

• What did you learn about gymnosperms? A conclusion is made with the help of a teacher. Available on a slide in a presentation.

Conclusion: only trees, shrubs and vines. Seeds have a supply of substances, the embryo is protected. The seeds lie open on the surface of the scales. There are male and female cones. The needles have a dense skin and are covered with wax, therefore they evaporate little water and are adapted to adverse conditions.

And now we will conduct laboratory work and learn how to identify plants by signs.

Lab (p. 79 ). "Study of the structure of needles". I recommend considering only the needles of two plants (lack of time). For example, Scotch pine and spruce.

Conclusion about the difference of needles. Made by students.

Message from students about pine and spruce. The rest of the students complete the table. The first line is helped by the teacher. The second is filled out on their own, after listening to the report. Slide

plant name	living conditions	cones	Peculiarities	Age
pine	light-loving In dry forests	Male - greenish-yellow, collected in groups at the base of young shoots Female - reddish, solitary, lignified	Tall, slender, without lower branches Sprawling in open areas	350, 400 years
spruce
larch
juniper

Homework: Complete the table.

III. Consolidation.

Questions for the class.

1. What is the main difference between seed plants and spore plants?
2. Why are conifers called otherwise gymnosperms?
3. What conditions are necessary for the life of pine and spruce?
4. What plants are gymnosperms?
5. How does a person use conifers? What does he get from them?

Labyrinth. Shown on the slide. distributed to each table. Used textbook. Work in pairs .

Answer key: 1, 6, 7, 8, 13, 14, 9, 10, 15, 19, 24, 20, 25.

Students independently check and rate themselves (if the maze is completed completely - “5”, 7-12 correct moves - “4”, less - “3”)

Final word:

No matter how widely these plants are used by man. It is necessary to think about their protection. Conifers are cut down everywhere. The taiga is getting poorer. At the same time, there is less and less oxygen and water. Conifers are not resistant to air pollution. Therefore, our industry is destroying them. The poem is on the slide. Read by heart by the student

We speak in front of all the people:
To prolong nature's age,
Gotta help nature
The friend of nature is man.
For the years to pass peacefully
flourished for century century,
To be a friend to all nature
Every person should!

IV. Summarizing.

Gymnosperms

Slides: 13 Words: 543 Sounds: 0 Effects: 0

Department Gymnosperms. Characteristics of gymnosperms. The structure of gymnosperms. The stomata are immersed in the leaf tissue, which reduces the evaporation of water. Reproduction of conifers. Scales are located along the axis of such a bump. A mature pollen grain consists of two cells. value in nature. Gymnosperms play an important role in nature. Significance in human life. Gymnosperms are also used by humans in their economic activities. The entire sailing fleet is built mainly from pine. Many of the conifers are still excellent building material. The core of some tropical forms (eg cycads) is eaten. - Gymnosperms.ppt

Lesson Gymnosperms

Slides: 18 Words: 432 Sounds: 0 Effects: 0

Lesson-journey "Gymnosperms". Cultivate respect for nature. Lesson plan. 1.Organizational part Reporting the tasks of the lesson 2.Independent work Fill in the table. Answer the questions. Test. Learning new material. Pinery. Spruce ordinary. Juniper. Fir. Common larch. Laboratory work "The structure of needles and cones." Common pine. Consider the shape, size, color of the cones. Fill the table. Consolidation of knowledge. Tasks: 1) Arrange in order of complexity: algae, lichens, mosses, ferns, gymnosperms. Complete the diagram. - Lesson Gymnosperms.ppt

Department of gymnosperms

Slides: 44 Words: 3116 Sounds: 0 Effects: 15

Department Gymnosperms. Common pine. Gnetum. Ginkgo. Department Gymnosperms (Pinophyta, or Gymnospermae). General characteristics of the department The most ancient department of seed plants. Represented by numerous fossils and modern views(about 700 in total). The type genus is pine (Pinus). Features of the life cycle. Alternation of generations with dominance of the asexual generation (sporophyte). The most important evolutionary acquisition of seed plants is internal fertilization. All gymnosperms are heterosporous plants. life forms. There are no herbaceous forms. The secondary xylem usually consists of scalariform tracheids (not vessels). - Division Gymnosperms.ppt

Gymnosperms

Slides: 9 Words: 211 Sounds: 0 Effects: 0

Gymnosperms. Definition of gymnosperms. The structure of the leaves of coniferous plants. The structure of the cone. The value of coniferous trees. Gymnosperms - plants that do not have fruits and the seeds lie open, naked. Conifers are classified as gymnosperms. Coniferous - plants that have modified leaves - needles. Needles are modified needle-like leaves of coniferous plants. Seeds are located in cones on hard scales. Immature cones are greenish, with tightly pressed scales. In a mature brown cone, the scales open. In gymnosperms, seeds are not in fruits, but in cones. - Gymnosperms.ppt

Biology Gymnosperms

Slides: 9 Words: 382 Sounds: 0 Effects: 26

Biology. Department Gymnosperms. General characteristics. Lesson plan. Examination homework(work with tests). Plan general characteristics Gymnosperms. About 700 species. Woody plants, rarely shrubs. The leaves are needle-shaped, slightly flattened or scaly. Evergreens. They do not form fruits. There are no real vessels. Diverse plants. Fertilization occurs without the participation of water. Male gametes are non-motile sperm. Reproduction through seeds. In gymnosperms, the seeds are not covered by the walls of the fruit. Seeds are formed on modified, shortened, generative shoots - cones. - Biology Gymnosperms.ppt

Gymnosperms

Slides: 9 Words: 80 Sounds: 0 Effects: 8

Department of gymnosperms. Cones develop on the branches. Sex cells are formed in cones, fertilization occurs, seeds are formed. Seeds are located on the scales openly (naked). What plants did the gymnosperms come from? Life forms of gymnosperms. Trees. Shrubs. Representatives of the coniferous class. Juniper. Cypress. Yew. The Pine family is the most numerous among the conifers. - Plants of the gymnosperms department.ppt

General characteristics of gymnosperms

Slides: 18 Words: 511 Sounds: 0 Effects: 17

Department Gymnosperms. The most popular children's song. And brought a lot of joy to the kids. Conifers are widely distributed on Earth. There are no herbaceous plants among conifers, but only shrubs and trees. The leaves of most conifers are narrow, needle-like - the so-called needles. On swampy soils, the main root is poorly developed. Plan of general characteristics of gymnosperms. About 700 species. Woody plants, rarely shrubs. The leaves are needle-shaped, slightly flattened or scaly. Evergreens. They do not form fruits. There are no real vessels. Diverse plants. - General characteristics of gymnosperms.pptx

Reproduction of gymnosperms

Slides: 14 Words: 115 Sounds: 0 Effects: 0

Topic: Reproduction of gymnosperms. Gymnosperms. Choose the excess. asexual reproduction sexual reproduction Sperm Ovum. Gamete Ovum Sperm Fertilization. Chlamydomonas Ulothrix Moss cuckoo flax. What mode of reproduction is depicted in chlamydomonas? What mode of reproduction is depicted in ulotrix? Which moss is a female plant? Horsetail Moss Pine Fern. The structure of the cone. Scheme "Pollination and changes occurring in the cone." Scheme "Formation of seeds in pine". Ovum Sperm Zygote Embryo Seed. Ovule Endosperm The seed coat. -

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From history Gymnosperms are the most ancient group of seed plants. They appeared on Earth over 350 million years ago, long before the emergence of angiosperms. Imprints of seed ferns are found in the deep layers of the earth's crust.

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Features of gymnosperms Main Feature of these plants is reproduction by means of seeds. Seeds develop from ovules (ovules) and lie open (naked) on the scales of female cones. Hence the name - gymnosperms. Another feature of gymnosperms is the complete independence of the fertilization process from the presence of water due to the appearance of a pollen tube through which male gametes moving towards the female.

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Classes of Gymnosperms The department of gymnosperms unites 6 classes: seed ferns, cycads, bennetites, gnets, ginkgos, conifers. To date, seed ferns, bennetites, have completely died out and their existence is evidenced only by prints and fossils of various organs of these plants. Of the ginkgos, only one species has survived to this day - ginkgo biloba.

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The most numerous and most common class of modern gymnosperms are conifers. There are only about 560 species of them, despite the fact that conifers surpass all living gymnosperms in antiquity. The most ancient of conifers are plants of the pine family (pine, spruce, fir, etc.). They have existed for more than 300 million years and have retained the main structural features of their ancestors. conifer class

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Scots pine. Features of the structure and vital activity of gymnosperms can be considered on the example of Scots pine. This tree is up to 40 - 50 m high, lives up to 400 years, grows everywhere: on poor sandy soils, sphagnum bogs, limestone slopes.

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Pine is a drought-resistant plant Pine is a drought-resistant plant. This is due to the fact that its leaves - needles - are narrow, long, covered with a thin dense skin with a small number of stomata. Therefore, pines economically evaporate water, easily tolerate drought. The needles contain vitamin C, release substances called phytoncides, which kill pathogenic microbes.

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Pine is a photophilous plant. It is one of the first to populate forest-free areas, but does not tolerate shading well. In the forest, pines develop deep roots well, and on sandy soil, surface roots. Pines growing in swamps develop only superficial roots. Hyphae of fungi often settle on the roots, mycorrhiza is formed, due to which the supply of water and mineral salts to the tree improves. Pine - light-loving plant

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Pine wood Pine wood consists mainly of tracheids, which have a polygonal or, less commonly, round shape in cross section. Bordered pores are arranged in one or two rows on their radial walls. Annual rings are clearly expressed in the wood, so it is not difficult to determine the age of the pine.

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Pine reproduction Pine is a monoecious plant: male and female cones are formed on the same individuals. An adult pine plant is a sporophyte. In spring, small reddish cones are formed on the tops of young pine shoots - female cones of the first year. The cone consists of an axis on which the scales are located, and on each scale there are two ovules. At the base of young shoots of pine, greenish-yellow cones are located in groups - male cones. They form pollen in special pollen sacs.

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These sacs are arranged in pairs on transparent scales. If you look at pollen under a microscope, you can see that each speck of dust is equipped with two air sacs. - Thanks to these air sacs, pollen is easily carried by the wind over long distances. Even at an altitude of 3 thousand meters, as well as 2 km from the pine forest, pine pollen is found. This is a pine tree's adaptation to wind pollination. pollen sacs

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Ripe with the help of the wind Ripened pollen with the help of wind and air sacs falls on the ovules of female cones, after which their scales tightly close and stick together with resin. The speck of dust remains inside the ovule until the next spring. It takes about 13 months from pollination to fertilization. When the egg matures, a speck of dust germinates, a pollen tube develops from the vegetative cell, and two sperm cells develop from the generative cell. One of the sperm merges with the nucleus of the egg, and the second dies. From the resulting zygote, an embryo develops with a margin nutrients. When the seeds ripen, the lignified scales diverge and the seeds, each with a long wing, spill out of the cone. They are picked up by the wind and dispersed over long distances. Seeds germinate in spring if conditions are favorable.

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Both in nature and in human life, conifers take second place after flowering plants. coniferous forests accumulate a huge amount organic matter, it is a valuable source of wood and many other plant products. From conifers, ornamental and construction wood, fuel are obtained, and paper is made. Many types of conifers contain balsams, resins, from which, after distillation, valuable chemical substances. Second place after flowering plants