What evidence exists for the historical development of plants. Evidence of evolution
It is impossible to prove modern ideas about the evolution of life by direct methods. The experiment will last for millions of years (civilized society is no more than 10 thousand years old), and a time machine will most likely never be invented. How is truth obtained in this area of knowledge? How to approach the burning question “Who came from whom”?
Modern biology has already accumulated a lot of indirect evidence and considerations in favor of evolution. Living organisms have common features - biochemical processes proceed in a similar way, there are similarities in external and internal structure and in individual development. If the embryos of a turtle and a rat are indistinguishable in the early stages of development, then is this suspicious similarity a hint of a single ancestor from which these animals descended over millions of years? It’s about the ancestors modern species paleontology - the science of fossil remains of living beings - will tell. Interesting Facts, giving food for thought, provides biogeography - the science of the distribution of animals and plants.
EVIDENCE OF EVOLUTION
Morphological
Embryological
Paleontological
Biochemical
Biogeographic
1. Biochemical evidence of evolution.
1. All organisms, be they viruses, bacteria, plants, animals or fungi, have a surprisingly similar elementary chemical composition.
2. For all of them, proteins and nucleic acids play a particularly important role in life phenomena, which are always built according to a single principle and from similar components. A high degree of similarity is found not only in the structure of biological molecules, but also in the way they function. Principles of genetic coding, protein biosynthesis and nucleic acids are the same for all living things.
3. The vast majority of organisms use ATP as energy storage molecules; the mechanisms for breaking down sugars and the main energy cycle of the cell are also the same.
4.Most organisms have a cellular structure.
2.Embryological evidence of evolution.
Domestic and foreign scientists have discovered and deeply studied the similarities in the initial stages of embryonic development of animals. All multicellular animals go through the blastula and gastrula stages during individual development. The similarity of embryonic stages within individual types or classes is particularly clear. For example, in all terrestrial vertebrates, as well as in fish, the formation of gill arches is found, although these formations have no functional significance in adult organisms. This similarity of embryonic stages is explained by the unity of origin of all living organisms.
3. Morphological evidence of evolution.
Of particular value for proving the unity of the origin of the organic world are forms that combine the characteristics of several large systematic units. The existence of such intermediate forms indicates that in previous geological eras there lived organisms that were the ancestors of several systematic groups. A clear example of this is the single-celled organism Euglena verida. It simultaneously has characteristics typical of plants and protozoa.
The structure of the forelimbs of some vertebrates, despite the performance of these organs, is completely different functions, are fundamentally similar in structure. Some bones in the skeleton of the limbs may be absent, others may be fused, the relative sizes of the bones may vary, but their homology is quite obvious. Homologous are those organs that develop from the same embryonic rudiments in a similar way.
Some organs or their parts do not function in adult animals and are superfluous for them - these are the so-called vestigial organs or rudiments. The presence of rudiments, as well as homologous organs, is also evidence of a common origin.
4. Paleontological evidence of evolution.
Paleontology points to the causes of evolutionary transformations. The evolution of horses is interesting in this regard. Climate change on Earth has caused changes in the horse's limbs. In parallel with the change in the limbs, a transformation of the entire organism took place: an increase in body size, changes in the shape of the skull and complication of the structure of the teeth, the emergence of a digestive tract characteristic of herbivorous mammals, and much more.
As a result of changes in external conditions under the influence of natural selection, a gradual transformation of small five-toed omnivores into large herbivores occurred. The richest paleontological material is one of the most convincing evidence of the evolutionary process that has been going on on our planet for more than 3 billion years.
5. Biogeographic evidence for evolution.
A clear indication of the evolutionary changes that have occurred and are ongoing is the spread of animals and plants across the surface of our planet. Comparison of the animal and plant world of different zones provides rich scientific material to prove the evolutionary process. The fauna and flora of the Paleoarctic and Neoarctic regions have much in common. This is explained by the fact that in the gap between the named areas there was a land bridge - the Bering Isthmus. Other areas have little in common.
Thus, the distribution of animal and plant species over the surface of the planet and their grouping into biographical zones reflects the process historical development Earth and the evolution of living things.
Island fauna and flora.
To understand the evolutionary process, the flora and fauna of the islands are of interest. The composition of their flora and fauna depends entirely on the history of the origin of the islands. A huge number of diverse biographical facts indicate that the characteristics of the distribution of living beings on the planet are closely related to the transformation earth's crust and with evolutionary changes in species.
1. The phylogenetic series of the horse is considered evidence of evolution
1. Embryological
2. Paleontological
3. Physiological
4. Genetic
Explanation: phylogeny is the historical development of an individual. Evidence of the existence of ancestors that were different from modern horses can only be paleontological, that is, skeletons of ancestral forms. The correct answer is 2.
2. What can you learn about by studying the finds of plant imprints and fossils in ancient layers of the Earth?
1. About seasonal changes in plant life
2. On the historical development of plants
3. On the individual development of plants
4. How photosynthesis was carried out in ancient plants
Explanation: imprints and fossils are paleontological evidence of the historical development of plants (for example, coal was formed from the remains of ferns, which means that ferns are very ancient organisms). The correct answer is 2.
3. What is evidence of the historical development of plants?
1. The appearance of chlorophyll, the emergence of photosynthesis
2. Change of conditions environment
3. Cellular structure of plants
4. Presence of “living fossils”, transitional forms
Explanation: However, the evidence is the presence of transitional forms and “living fossils”. In this way we can "see" the evolution of plants. This can also be seen in the example of animals. The correct answer is 4.
4. Paleontological evidence of the evolution of the organic world includes
1. Similarity of vertebrate embryos
2. Similarities between island and mainland flora and fauna
3. Presence of fossils of transitional forms
4. Presence of rudiments, atavisms
Explanation: paleontological evidence - various fossils, for example, fossils of transitional forms. The correct answer is 3.
5. The coccygeal bone, appendix, the remnant of the third eyelid in the corner of the human eye is
1. Similar bodies
2. Homologous organs
3. Atavisms
4. Rudiments
Explanation: all of the listed signs are organs left over from ancestors and have lost their functions. Such organs are called vestigial. The correct answer is 4.
6. Mimicry is the result
1. Increasing the level of organization of living things
2. Selection of similar mutations in different species
3. Complications in the development of organisms
7. The appearance of dark-colored butterflies in a population of light-colored individuals of the birch moth as a result of hereditary variability is called
1. Warning paint
2. Mimicry
3. Industrial melanism
4. Imitative resemblance
Explanation: this phenomenon occurs due to strong exhaust emissions from factories and various industries, so dark butterflies become invisible to predators, but white ones become visible. The correct answer is 3.
8. Bee flies appearance look like bees. What form of adaptation does this sign illustrate?
1. Seasonal coloring
2. Dismembering coloring
3. Mimicry
4. Disguise
Explanation: this situation describes the phenomenon of mimicry. The correct answer is 3.
9. The habitat occupied by a species in nature is a criterion
1. Geographical
2. Ecological
3. Genetic
4. Physiological
Explanation: the correct answer is geographical, since the range is the territory (that is, a geographical object) that the population occupies. The correct answer is 1.
10. The formation of fitness in organisms is referred to as
2. Evidence of evolution
3. The results of evolution
4. The driving forces of evolution
Explanation: fitness is the most important result of evolution. This result is achieved with the help of the driving forces of evolution: heredity, variability, natural selection and the struggle for existence. The correct answer is 3.
11. In accordance with the physiological criterion, all individuals of the species have
1. General range
2. A specific set of chromosomes
3. Same chemical composition
4. Similar life processes
Explanation: physiology is the science of biochemical processes in living organisms, so the correct answer is 4.
12. In modern biological science, a population is considered to be
1. A set of organisms of one kingdom
2. Individuals forming the food chain
3. Individuals different types, forming a biocenosis
4. Individuals of the same species living in the same territory
Explanation: population - a group of individuals of the same species living in the same territory and freely interbreeding with each other. The correct answer is 4.
13. What is the name of the species criterion, which is based on the similarity of life processes?
1. Morphological
2. Ecological
3. Geographical
4. Physiological
Explanation: Life processes are studied by the science of physiology. Therefore, the species criterion that describes such processes in a particular species is called physiological. The correct answer is 4.
14. Similar composition organic compounds, inherent in individuals of one species, characterizes the criterion
1. Morphological
2. Biochemical
3. Genetic
4. Physiological
Explanation: the composition of organic compounds describes a biochemical criterion, since biochemistry is the science of chemical composition living organisms. The correct answer is 2.
15. As a result of the isolation of populations, new species are formed, which
1. They cannot interbreed with each other
2. They have significant external differences
3. Have significant differences in internal structure
4. When crossed, they produce fertile offspring
Explanation: the resulting species cannot interbreed due to genetic differences (cells will recognize cells of another species as foreign and reject them). The correct answer is 1.
16. A similar composition of organic compounds inherent in individuals of the same species characterizes the criterion
1. Morphological
2. Biochemical
3. Genetic
4. Physiological
Explanation: The composition of organic compounds in the body is described by a biochemical criterion. The correct answer is 2.
Tasks for independent solution
1. Paleontological evidence of evolution includes
1. Similarities between primal beasts and birds
2. Rudiments of limbs in modern cetaceans
3. Similarities between the embryos of birds and reptiles
4. Findings of skeletons of ancient lobe-finned fish
The correct answer is 4.
2. Organs that have lost their original function during evolution are called
1. Atavisms
2. Rudiments
3. Homologous
4. Similar
The correct answer is 2.
3. Adaptability of the mole cricket insect to living in soil - presence
1. Chitinous cover
2. Well-developed mouthparts
3. Bucket-shaped forelimbs
4. Mosaic structure of the visual organs
The correct answer is 3.
4. The development of multicellular organisms from a zygote serves as evidence
1. The origin of multicellular organisms from unicellular ones
2. Adaptation of organisms to environmental conditions
3. Individual development of plants and animals
4. Environmental influences on the development of organisms
The correct answer is 1.
5. Thanks to indirect development in animals, competition between
1. Individuals of different species
2. Populations of different species
3. Larvae and adult forms
4. Adults of the species
The correct answer is 3.
6. The results of evolution include
1. Hereditary variability
2. The struggle for existence
3. Adaptability of organisms
4. Natural selection
The correct answer is 3.
7. Paleontological evidence of evolution is
1. Imprint of Arechaeopteryx
2. Species diversity of organisms
3. Adaptation of fish to life at different depths
4. The presence of shells in mollusks
The correct answer is 1.
8. What ancient animals were the most likely ancestors of vertebrates?
1. Arthropods
2. Flatworms
3. Shellfish
4. Skullless
The correct answer is 4.
9. The main result of evolution is
1. Adaptation of organisms to their environment
2. Population fluctuations
3. Decrease in the number of populations of the species
4. The struggle for existence between individuals of the same species
The correct answer is 1.
10. Organs are considered homologous
1. Similar in origin
2. Performing similar functions
3. Buildings that do not have a general plan
4. Different in origin
The correct answer is 1.
11. Juicy fruits of plants can be considered as an adaptation to
1. Storage of organic substances
2. Storage of minerals
3. Seed distribution
4. Vegetative propagation
The correct answer is 3.
12. Embryological evidence of the evolution of vertebrates is the development of the embryo from
1. Zygotes
2. Somatic cell
3. Controversy
4. Cysts
The correct answer is 1.
13. Adaptations in individuals of a population over a long series of generations arise due to
1. Genetic drift
2. Natural selection
3. Intraspecific forms of struggle
4. Modification variability
The correct answer is 2.
14. What is the significance of warning coloring on animals?
1. Makes animals invisible
2. Scares away enemies
3. Attracts members of its own species
4. Exacerbates intraspecific struggle
The correct answer is 2.
15. Modification of leaves in coniferous plants serves as an adaptation to
1. Improving mineral nutrition of plants
2. Increasing the intensity of photosynthesis
3. Economical use of water
4. Capturing sunlight
The correct answer is 3.
16. Amphibians living in temperate climates, as a result of evolution, have developed an adaptation to endure unfavorable conditions -
1. Stocking feed
2. Numbness
3. Moving to warm areas
4. Color change
The correct answer is 2.
17. What is the significance of the bright colors of ladybugs?
1. Attracts individuals of the opposite sex
2. Warns of inedibility
3. Indicates belonging to the same species
4. Attracts predatory insects
The correct answer is 2.
18. Has a warning color
1. Ladybug
2. Snowy owl
4. Lake frog
The correct answer is 1.
19. What type of protective coloring is called mimicry?
1. Coloring that dismembers the body
2. Bright coloring, signaling the toxicity of the organism
3. Imitation in coloring of a less protected species to a more protected one
4. Merging the color of animals with surrounding objects
The correct answer is 3.
20. Adaptation of plants and animals to their environment
1. Depends on the anthropogenic factor
2. Formed during the evolution of organisms
3. Occurs during organ exercise
4. Is absolute and unchangeable
The correct answer is 2.
21. In a frog, crocodile and hippopotamus, the eyes and nostrils protrude above the surface of the head, this indicates their
1. Kinship
2. Development along the path of aromorphosis
3. Adaptation to life in water
4. Biological regression
The correct answer is 3.
22. Adaptation of an animal species to its environment - the result
1. Caring for the offspring
2. Exercises of organs and direct devices
3. Natural selection of hereditary changes
4. High numbers of individuals in populations
The correct answer is 3.
23. Scientists have discovered that twin species similar in external structure, life activity and habitat, differ according to the criterion
1. Ecological
2. Physiological
3. Genetic
4. Morphological
The correct answer is 3.
24. What example illustrates the manifestation of a biotic factor in the natural environment?
1. Pollution of water bodies located next to agrocenoses
2. Ladybug larvae eating apple aphids
3. Freezing of wheat seedlings during spring frosts
4. Lowering groundwater levels during prolonged drought
The correct answer is 3.
25. Unites individuals into one population
1. Free crossing and shared territory
2. Weakening of the struggle for existence
3. Lack of food and living in biocenosis
The correct answer is 1.
26. The area occupied by a species in nature is a criterion
1. Ecological
2. Geographical
3. Morphological
4. Physiological
The correct answer is 2.
27. The geographical mode of speciation is characterized by
1. Expansion of range, emergence of barriers between populations
2. The occurrence of mutations without changing the boundaries of the range
3. Intensification of intraspecific competition within the former range
4. Diversity of environmental conditions within the range
The correct answer is 1.
28. The elementary unit of evolution is considered
1. Organism
2. Family
3. Population
4. View
The correct answer is 3.
29. By what morphological character do birds differ from other chordates?
1. Chromosome set
2. Feather cover
3. Ability to fly
4. Intensive metabolism
The correct answer is 2.
30. Many species of animals and plants consist of several populations, which
1. Increases fluctuations in the number of individuals
2. Violates the stability of species
3. Causes an increase in their numbers
4. Provides diversity in their gene pools
The correct answer is 4.
31. Microevolution leads to change
1. Species
2. Childbirth
3. Families
4. Squads
The correct answer is 1.
32. Why is a population considered the elementary unit of evolution?
1. Individuals are connected by food chains and food networks
2. It consists of individual interacting individuals
3. It is the smallest unit of a species that varies over time
4. The circulation of substances and the transformation of energy take place in it
The correct answer is 3.
33. A species is a closed system, since its individuals
1. They do not interbreed with individuals of another species
2. Unite into one population
3. Have the same genotypes
4. They are part of the same biogeocenosis
The correct answer is 1.
34. Evolutionary changes in the structure of the beak of Galapagos finches reflect their adaptation to
1. Collecting material for nesting
2. Living in open spaces
3. Eating different foods
4. Catching small rodents
The correct answer is 3.
35. What definition corresponds to the concept of “species”?
1. The totality of different populations of natural biocenosis
2. A set of heterosexual individuals
3. A group of individuals isolated in space
4. Genetically closed biological system
The correct answer is 4.
36. The ability of black henbane to synthesize and accumulate alkaloids is an indicator of the species criterion
1. Morphological
2. Genetic
3. Biochemical
4. Geographical
The correct answer is 3.
37. What underlies the morphological criterion of a species?
1. Species-specific set of chromosomes
2. The similarity of all life processes in individuals
3. Uniformity of habitat factors of the species
4. Similarity between appearance and internal structure individuals
The correct answer is 4.
38. Applying a morphological criterion to the description of a plant species means characterizing it
1. Flowering time
2. Area of distribution
3. Habitat
4. Structural features
The correct answer is 4.
39. The distribution of the great tit in Eurasia and North-West Africa is classified as a species criterion
1. Geographical
2. Genetic
3. Ecological
4. Morphological
The correct answer is 1.
40. The population is considered the unit of evolution, since
1. Her gene pool is capable of directed change
2. Its individuals are most related
3. Its individuals experience modification changes
4. Its individuals are characterized by a certain reaction norm
The correct answer is 1.
41. The characteristics and properties characteristic of a species are called
1. Alternative signs
2. Modifications
3. Criteria
4. Alleles
The correct answer is 3.
42. What does the appearance of new alleles in a population lead to?
1. The emergence of barriers to free crossing
2. Increased homozygosity of the population
3. Formation of a new species
4. Genetic heterogeneity of the population
The correct answer is 4.
43. Crossing of different species of tits living within the same forest area is prevented by
1. Different chromosome set
2. Differences in feed consumed
3. Violation of the light regime
4. Lack of nesting sites
The correct answer is 1.
Sections: Biology
Goals:
- summarize students’ knowledge about the main divisions of plants, identify the stages of complication of plant structure and factors in the evolution of the plant world;
- bring schoolchildren to the conclusion about the kinship and unity of all life on Earth, continue to develop in students the ability to analyze, draw conclusions, and reason logically using problem situations;
- test students' knowledge of previously studied material.
During the classes
1. Org. moment.
Greeting students and getting ready to work.
II. Setting goals and objectives for the lesson.
– Today I want to start the lesson with the words of S.Ya. Marshak (slide 1)
A man - even if he is a genius three times -
Remains a thinking plant.
Trees and grass are related to him,
Don't be ashamed of this relationship!
Read these lines carefully again and tell me what thoughts arose while reading.
Student answers (approximate):
- All living organisms have a cellular structure.
- Man is part of nature.
- No matter how smart a person is, he should not consider himself the king of nature.
- Man, trees, grass - these are all living organisms.
- Unity of origin of animals and plants.
So, life has existed on our planet for billions of years. It fills all its corners: lakes, rivers, mountains, deserts, and even the air is inhabited by living beings. It is estimated that over the entire history of life on Earth there have been 4.5 billion species of plants and animals. Nose ancient times the best minds humanity was interested in the questions: how did life arise and develop on our Earth? Have plants and animals always been the way they are now? Who was the first on Earth - plants or animals?
– Do these questions concern you?
– Which ones exactly?
(I ask the children what interests them most.)
– So let’s try to find answers to at least some of them in class today. Arrange the words basic, development, world, stages, plant, written on tablets, in the right order to make a meaningful sentence. This will be the topic of our lesson. ( Annex 1)
(Children make a sentence from the words and tell the topic of the lesson.)
We will write down the topic of the lesson “The main stages of development of the plant world” in a notebook. (slide 2)
And we all face common challenges: (slide 3)
- Determine the main stages of plant development;
- Identify signs of their complication in the process of historical development;
- Name the reasons (driving forces) for the evolution of plants;
- Make sure of the diversity of the plant world.
III. Testing students' knowledge.
- But before starting this research work, we will conduct a small test to prove that you are all ready to study the new section in the textbook.
Students' knowledge is tested in a differentiated manner, taking into account the level of preparation. Students with an average and low level of preparation work on cards (Appendix 2 AndAppendix 3 respectively).
Students with more high level preparation work together with the teacher:
The herbarium was issued: 1st row - algae and mosses, 2nd row - mosses and ferns, 3rd row - ferns and gymnosperms.
Task: Compare plant divisions. Where do they live? Indicate their differences in structure. How do they reproduce? How do they eat? Which plants are more progressive?
Prepare your cards. If your signal does not agree with my response signal, put (-) in your notebooks, the correct answer is (+) ( Appendix 4)
The cards have a specific color and represent different classes of plants:
- algae – blue color;
- mosses – green;
- ferns – brown;
- gymnosperms – yellow;
- all departments - multi-colored card.)
Questions:
- Kukushkin flax. (ferns, brown)
- Chlorella. (seaweed)
- Sunflower. (angiosperms)
- Spruce. (gymnosperms)
- Sphagnum. (mosses, green)
- Absorb carbon dioxide and release oxygen. (All)
- Formed coal deposits on Earth (ferns)
- The reproductive organ is the cone. (gymnosperms)
- Exclusively terrestrial, often evergreen (Gymnosperms)
- cuckoo flax (moss)
- Ulotrix. (seaweed)
- Laminaria (algae)
- Reproductive organs: pistil and stamen (angiosperms)
- Amphibians in the plant world. They have a spore capsule (fern)
- Orlyak. (ferns)
– Those who have not made a single mistake – score “5”, up to 3 mistakes – “4”, over 3 – “3”.
This can be done on sheets and turned in immediately. (Appendix 4)
Working with table No. 1 (slide 4)
– What can you say looking at this sign?
– But the table doesn’t have a name – what would you call it? (Evolution of the plant world.)
– What is “evolution”? (Refer to the dictionary).
Children read out answer options from V.I. Dahl’s dictionary, from TSB, from explanatory dictionary Ozhegova. – The word “evolution” is Latin and translated means “unfolding”, and in a broad sense - any change, development, transformation. In biology, the word “evolution” was first used in 1762 by the Swiss naturalist and philosopher Charles Bonnet.
– Where have you ever heard this word?
– Can we use it in class today?
– That’s right, because we can write the topic of our lesson “The main stages of development of the plant world” as “Evolution of the plant world.”
IV. Explanation of new material.
- So, let's turn the clock back. (the teacher turns the clock hands, which have terms instead of numbers)
We turn the clock hands and repeat the terms: prokaryotes, eukaryotes, autotrophs, heterotrophs.
Student: 3.5 billion years ago ancient earth very little resembled the planet on which we live. Its atmosphere consisted of water vapor, carbon dioxide and, according to some sources, nitrogen, according to others, methane and ammonia. There was no oxygen in the air of the lifeless planet. And, it must be said, the absence of oxygen was necessary for the emergence of life. The earth is covered with water. Heavy rains, accompanied by lightning strikes, have been raging on the planet for centuries. And in this “warm dilute broth” the first living organisms (coacervates) are already found. This hypothesis of the origin of life on Earth was first expressed in 1922 by Soviet biologist Alexander Oparin. It is difficult to call the resulting gelatinous lumps organisms; they are complex organic protein compounds. The structure of coacervates gradually became more complex - this is how the first simple unicellular organisms appeared.
Teacher: Right! According to Oparin, the distance from these “clumps” to the most primitive bacteria is no less than from an amoeba to a person. But let's assume who they are - these first living organisms:
- Prokaryotes or eukaryotes
- What type of nutrition was typical for them (autotrophs or heterotrophs)
- Who are they: animals or plants? (Discussion in progress).
Conclusion: The first living organisms that appeared on Earth were nuclear-free cells that fed on ready-made organic substances, and they cannot be classified either in the plant kingdom or in the animal kingdom.
We will record our knowledge in a table (lies on the tables) ( Appendix 5)
About 1 billion years have passed...
The land is still a bare desert. But a new gas appears in the water - oxygen. What does this indicate? What ancient organisms do you think could be responsible for the appearance of oxygen?
Student: These were the first simple organisms that ran out of nutrients found on Earth and some cells adapted to use sunlight to convert water and carbon dioxide into organic matter, i.e. a process arose photosynthesis. And as a result of photosynthesis, oxygen began to accumulate. – What method of feeding organisms appeared? Student Answer: These cells containing chloroplasts are autotrophs, i.e. They themselves synthesize the organic substances necessary for life using light energy. This is how the first ones appeared plants. – Other living beings have retained the same way of eating – heterotrophic, primary plants began to serve as food for them. These were the first animals. This happened during the Precambrian period. It lasted over 3 billion years. During this period, the structure of living beings was increasingly improved. The first single-celled plants, blue-green algae, learned to break down water. They accomplished a real feat - oxygen began to be released into the atmosphere. The composition of the air gradually approached the modern one, i.e. consisted of nitrogen, oxygen, carbon dioxide. This atmosphere contributed to the development of more advanced forms of life. Primary unicellular algae gave rise to multicellular algae.
– Let’s continue filling out the table.
– Over time, the climate on Earth has changed. Due to vibrations of the earth's crust, land appeared in place of some seas and oceans. The primary seas began to shallow. And thanks to oxygen, a layer of ozone appeared in the upper layers of the atmosphere, softening ultraviolet radiation. What began to happen to some ancient algae under the influence of new living conditions?
Student: Some algae have become more advanced and have adapted to live in damp places on land along the shores of water bodies. The transition of some plants from an aquatic lifestyle to a terrestrial one began. This happened ~ 350-400 million years ago. This is the most ancient group of terrestrial plants - psilophytes and rhinophytes. These plants covered the banks with a green carpet up to 25 cm high. They did not have roots, stems, or leaves, but were branching axes, on the underground parts of which rhizoids developed. In rhinophytes, tissue differentiation occurred: integumentary tissue (skin) and vascular bundles (wood and bast). Reproduction took place using spores.
Let's enter this information into a table.
– Pay attention to who rhyniophytes are. These are plants that lived on land, but nevertheless looked like algae.
And where else can we use this meaning – rhinophytes?
- Right. We will place this word in the empty frame of table No. 1 (slide 4).
These are the first higher plants that appeared on Earth.
Student answer:
– Rhiniophytes became the predecessors of fern and moss plants. Habitat: terrestrial, humid. The ferns developed a stem, leaves and roots. Ferns reached their peak during the Carboniferous period 300 million years ago.
Moss mosses - calamites - were spread out like a continuous carpet, ferns were branching, giant horsetails were towering in whole groves, lepidodendrons were turning green...
Let's write down the next stage of plant development in the tablet.
Physical exercise.
If you squat correctly, if you squat incorrectly, your hands are up.
- Rhiniophytes are the first land plants.
- Life first originated on land. (No)
- Ferns are terrestrial plants. (Yes)
- Nucleated cells were the first to appear on Earth) (yes)
At the end of the Carboniferous period, the climate on Earth became drier and colder, and tree ferns were replaced by the first primitive gymnosperms - seed ferns, the seeds developed on their leaves.
Living conditions continued to change. Where the climate became more severe, the ancient spores died out and the ancient gymnosperms appeared.
Student: Gymnosperms are classified as seed-bearing plants. They reproduce by seeds, which are not protected by the walls of the fruit (gymnosperms do not have flowers or fruits). The appearance of the seed important stage in plant evolution. The supply of nutrients in the seed ensures the life of the embryo when it is especially vulnerable - in initial period its development. Durable seed covers protect the embryo from unfavorable environmental factors. These evolutionary gains and the independence of fertilization from the presence of water (unlike spore plants) caused the widespread distribution of gymnosperms on land.
Let's enter this data into a table.
– 120 million years ago
What event happened during this time period?
Student: Angiosperms are descended from gymnosperms, but which families are more ancient and closer to gymnosperms has not been precisely determined by science. Some scientists consider catkins (birch, alder, willow) to be the oldest angiosperms, others consider polycarpids: magnolias and buttercups. Angiosperms differ from gymnosperms in the presence of a flower, fruit, sepals, petals, as well as the formation of a pistil, through which the pollen tube grows to the ovule and egg. The seeds of angiosperms develop inside the fruit and are well protected by the pericarp.
Angiosperms have dominated the Earth for more than 60 million years. This is the only group of plants that forms complex multi-layered communities. This contributes to more intensive use of the environment and the successful conquest of new territories.
Let's finish compiling our table.
Final table “Development of flora on Earth” (slide 5)
Exercise for the eyes:
When you open your eyes correctly, when you open them incorrectly, close them.
- Fertilization of gymnosperms remains highly dependent on water. (No)
- Gymnosperms are completely land plants (Yes)
- Angiosperms are no different from gymnosperms (no)
- Angiosperms arose about 120 million years ago.(yes)
- Gymnosperms arose about 10 million years ago. (No)
What is the word written on the board? (Palaeobotany.) What does it mean?
Student answer: Paleobotany is a science that deals with the study of plants of past eras . (slide 6)
Based on plant fossils, scientists have established that the older the organisms, the simpler their structure. The closer we get to our time, the more complex organisms become and more and more similar to modern ones.
– So, as a result of the development of the organic world, higher plants and highly organized animals appeared, as well as a thinking person who tries to get an answer to the question: “When and how did life arise on Earth?” And an inquisitive mind finds these answers (Slide 7)
Working with the textbook p. 260 (methods for studying ancient plants).
What branch of science is paleobotany? What kind of science is this?
V. Consolidation.
VI. Homework.
paragraph 58, questions orally. (slide 8)
Lesson summary, assessments
The diversity of plants that currently exist and previously lived on Earth is the result of the evolutionary process. The modern classification of plant organisms gives an idea not only of their exceptional diversity, but also allows us to trace the paths of formation of certain systematic groups of plants. All plants, according to the structure of the vegetative body, can be divided into lower (layered) and higher plants. Lower plants include bacteria and actnomycetes (conditionally), algae and lichens. Higher plants include long-extinct psilophytes and living mosses, ferns, horsetails, mosses, gymnosperms and angiosperms (flowering) plants.
Evidence of the historical development of plants is paleontological finds of their fossil remains. Among them are stromatolites - multi-layered formations from the remains of ancient primitive algae that lived in the seas and oceans, imprints of giant ferns, horsetails and mosses found in coal deposits and peat bogs, numerous spores and pollen in soil deposits of different geological ages.
The very first plant organisms - bacteria and blue-green algae - arose in the Archean era about 3 billion years ago. This is evidenced by the presence of terrestrial rocks of organic origin, which include limestone and marble. These were unicellular prokaryotic organisms, widespread in the seas and oceans, capable of autotrophic (chemo- and phototrophic) nutrition. Thanks to their vital activity in primary atmosphere oxygen appeared. The first autotrophic eukaryotes appeared about 1.5 billion years ago. These were the ancestors of modern unicellular algae, from which multicellular species of algae evolved. The emergence of the process of photosynthesis in the Archean era marked the beginning of the division of all living organisms into plants and animals. With the appearance of the first green plants - algae - the process of formation and accumulation of organic matter on Earth began.
In the Proterozoic era, the dominance of blue-green algae was replaced by the active development of green algae, including multicellular ones. The structure of their vegetative body became more complex, the surface area increased, which contributed to more productive photosynthesis. Large multicellular algae became widespread in the Cambrian period of the Paleozoic era. The emergence of plants onto land also dates back to the Paleozoic era. This happened at the end of the Silurian period, when continents arose as a result of mountain-building processes. The emergence of green algae on land was confined to the littoral zone of seas and oceans, to conditions of variable moisture. The first true land plants are considered to be psilophytes, a now extinct group. In connection with the land way of life, they acquired new qualities: to protect them from the changing conditions of the terrestrial environment, they were protected by integumentary tissues with stomata; mechanical tissues performed a supporting function; Primitive conductive tissues appeared. Psilophytes were forms transitional from lower to higher plants. Their further spread on land was prepared by the vital activity of prokaryotic organisms (blue-green algae, bacteria) and fungi, which formed the primary soil cover.
The Carboniferous period - the dominance of ferns, which had a number of advantages over psilophytes: developed root and vascular systems, leaves as an effective organ of photosynthesis. And although in reproduction the ferns were still closely associated with water, since their life cycle had flagellated stages, they formed vast forests on the vast territory of the then continents, created fertile soil cover, and enriched the atmosphere with the oxygen necessary for the development of animals. The appearance of fundamentally belongs to the same period new group plants - seed ferns, which are known only in the form of fossil remains. These were the direct ancestors of modern gymnosperms. The emergence of the seed determined the further progress of higher plants: firstly, the presence of the seed made the sexual process completely independent of the presence of water, secondly, the seed protected the embryo located inside it from the adverse effects of the external environment, thirdly, the seed contained reserve nutrients necessary for the initial stages of embryo development.
In the Permian period of the Paleozoic era, the humid climate gave way to a dry one, which led to the death of giant ferns, tree-like horsetails and mosses, as well as seed ferns. Only ancient gymnosperms that survived until the end of the Mesozoic era turned out to be viable. Gymnosperms switched to a fundamentally new type of fertilization: germ cells began to develop in their internal tissues. The male reproductive cell did not come into contact with the external environment, but reached the egg, passing inside the pollen tube. This contributed to the further conquest of land, and the adaptation of seeds to being carried by wind and water helped to quickly populate new territories.
Further complication of the reproductive organs of plants led to the emergence of a flower, which became a universal adaptation to a more effective pollination process than in gymnosperms. The ovary of angiosperms protects the ovule; the seeds develop inside the ovule, which serves them both as protection and as a source of nutritional material. Angiosperms quickly conquered the earth's surface and even mastered aquatic habitats in the silt of their endurance in different climatic and soil conditions. Thanks to natural selection, angiosperm flowers have acquired the widest range of pollination adaptations. The simultaneous evolution of pollinating insects played a major role in their development; the present time is the dominance of angiosperms, although both gymnosperms and spores have disappeared from the face of the earth. The vast majority of flowering plants are concentrated in tropical latitudes. These are predominantly woody species. In subtropical and temperate latitudes they are common along with conifers, and in northern sprats they are inferior in distribution.
Human economic activity causes significant damage to the richness and diversity of plant matter. The protection of plants must be carried out in different directions: this includes the preservation of their natural habitats, a ban on the collection and use in economic activities of many rare and endangered species, and the creation of nature reserves and sanctuaries where the preservation of plants in their natural conditions is ensured.
"Evidence for the Historical Development of Plants"
I. Check of knowledge.
Questions No. 1
When did planet Earth originate? (5 billion)
When did the first living organisms appear? (2.5 - 3 billion) But these were precellular life forms - small microscopic lumps of mucus.
When did the first single-celled organisms appear? (1.5 – 2 billion)
How did the first living organisms eat?
Where did living organisms originate?
Indicate which type of nutrition appeared first: heterotrophic or atotrophic?
What changes in the structure of the cell made it possible to switch to an autotrophic type of nutrition?
What is photosynthesis?
What changes took place in the Cosmos after the emergence of the process of photosynthesis? (atmosphere)
Where did multicellular organisms, both plant and animal, originate? (water)
Questions No. 2
Name the organisms that gave rise to the first multicellular algae.
What changes on Earth necessitated reaching land? (oscillations of the earth's crust, ebb and flow, drainage)
Name the most ancient group of plants that were the first to reach land.
Name the adaptations in the structure of the first land plants that helped them live on land.
Name the organisms that probably evolved from psilophytes?
What was the climate like on Earth during the reign of pteridophytes? (wet)
Why does the air have to be humid?
Name the organisms that gave rise to angiosperms.
What structural features provided angiosperms with a dominant position on Earth?
Checking d/z
Psilophytes - the first land plants, lived 420-400 million years ago. Died out. They grew along the banks of reservoirs. Green. Multicellular.
There were no organs yet, there were rhizoids.
There were fabrics: integumentary (skin), conductive (wood, bast)
Reproduction by spores.
Working with a table on the board.
| Changing conditions of existence | Changes in the structure of the body |
| Nutrient depletion in the primordial ocean | Chlorophyll (photosynthesis) atmosphere |
| Oscillations of the earth's crust | Fabrics (plant access to land) |
| Warm and humid climate | Organs (fern flowering) |
| Climate change | Seed (seed ferns – gymnosperms) |
Working with text *89
What science proves that vegetable world evolved?
What are fossils?
What are fingerprints?
Their significance for science?
Why do we now call araucaria, gingo, and tree ferns living fossils?
III. D/z*89.90, prepare for s/r on the topic.
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