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N. I. Sonin, V. I. Sonina
Biology. Living organism. 6th grade
Dear sixth graders!
In that academic year you continue to study biology. Biology is a science, or rather, a complex of sciences about life, about living organisms, which together make up wildlife.
The textbook you are holding in your hands is called Living Organism. Of course, you could call the textbook simply “Organism”, because the objects of inanimate nature that you learned about in primary school and when studying biology in grade 5, cannot be called organisms. Therefore, it is obvious that the textbook will deal with objects of wildlife. But the words “life”, “living” (organism), “living” (nature) emphasize movement, change, complex work that takes place inside each organism, within communities of organisms.
This year you and I have to define the concept of “life”, answer important questions: “Why are objects in nature so different in shape, size, behavior and meaning, such as a bacterium, a boletus mushroom, a forest lily of the valley, an apple tree, a dog, an elephant, a monkey and man, can be called living organisms? What unites them? Why can’t a robot that can have an outward resemblance to a person, can perform certain work and even “think” (solve problems, play chess, etc.) be called a living organism?
You will answer these and other questions by studying the textbook you have opened. It is only important to remember: to study does not mean to memorize, that is, to learn by heart. Memorizing the texts of textbook paragraphs without understanding them will not give you the opportunity to reflect, analyze, answer questions. When reading the text of the textbook, do not get distracted. Read with concentration, look at the pictures, ask yourself questions, try to answer them or find the answer in the text of the textbook. Learning only becomes interesting when it is clear what and why you are studying!
The structure of living organisms
Life activity of organisms
Organism and environment
Each topic is posted on several spreads. It contains the main educational material, which you must study, and additional, indicated by the sign.
The paragraph marked with an asterisk (*) contains material that is optional for study.
In some paragraphs, you will see text in a frame of green dots. Pay attention to it. This is interesting information on the topic of the paragraph that will be useful to you in the future. But if you get to know them now, it will be easier for you to study biology in the future.
At the end of each paragraph, you will find questions to test your knowledge by answering. We also recommend that you complete the tasks in workbook and solve tests. In a notebook for laboratory work and independent observations, do laboratory works. Imagine that you are a novice scientist, write down the results of your observations in a notebook and be sure to try to draw conclusions or “scientific” assumptions.
You will be greatly assisted in the course electronic application created for the tutorial. Thanks to him, even complex issues will become clearer and more accessible.
The study of a living organism is the beginning of the path to the knowledge of wildlife, of which we are a part. We wish you good luck in knowing yourself, your place in the world of living organisms around you and your significance in the amazing life of nature!
Part 1. The structure of living organisms
1. The cell is a living system
2. Cell division
3. Tissues of plants and animals
4. Organs of flowering plants
5. Organs and systems of animal organs
6. What have we learned about the structure of living organisms
1. The cell is a living system
Life on our planet is extremely diverse. Land, ocean, soil, even the air are inhabited by numerous organisms. Scientists believe that there are currently more than 2.5 million species on Earth. But no matter how great this variety of life is, it is based on a cell. Outside the cell, life has not been found on our planet. The only exception is viruses. They have a non-cellular structure, but are able to multiply only inside the cells of other organisms.
According to the structure of the cell, all living beings are divided into two large groups - pre-nuclear (non-nuclear) and nuclear. The cells of pre-nuclear (non-nuclear) organisms - bacteria, blue-green algae (cyanobacteria) are most simply arranged. The cells of nuclear organisms - fungi, plants and animals - have a nucleus and, in comparison with non-nuclear organisms, also have a more complex and varied structure.
Let us dwell on the structure of the nuclear cell in more detail. Any cell has a plasma membrane (from the Latin "membrane" - skin, film). It protects the internal contents of the cell from the effects of the external environment. Outgrowths and folds on the surface of the membrane contribute to the strong connection of cells to each other. The membrane is permeated with the thinnest tubules. Through the tubules of the membrane, nutrients and waste products of the cell are transported.
Seaweed, whose size reaches 8 cm, is one giant cell
Liver moss is one of the most simply organized plants.
Blooming Ivan da Marya
plant cell
unicellular animal amoeba
animal cage
An adult nematode (worm) consists of only 959 cells.
In plants plasma membrane the outer side is adjacent to the dense shell, made up of cellulose (fiber). The shell serves as the outer frame of the cell, giving it a certain shape and size, performs protective and supporting functions, and participates in the transport of substances into the cell.
The internal environment of the cell is cytoplasm, it contains the nucleus and numerous organelles. It consists of a viscous semi-liquid substance. The cytoplasm binds organelles together, provides the movement of various substances and is the environment in which numerous chemical reactions take place.
The cytoplasm is penetrated by a network of numerous small tubules and cavities connected to each other. This endoplasmic reticulum. It makes up 30-50% of the cell volume. The endoplasmic reticulum connects all parts of the cell with each other, participates in the formation and transportation of various organic substances. Performs important functions in the cell golgi apparatus. It is a stack of flattened membrane sacs - cavities in which various substances accumulate and sort. Small membrane vesicles are separated from the Golgi apparatus, in which substances can be transferred to any part of the cell and even released from the cell.
Lysosomes- one of the smallest organelles of the cell - is also formed in the Golgi apparatus. These small vesicles contain substances that digest food particles inside the cell, destroy obsolete organelles and even whole cells. Remember what happens to the tadpole's tail over time, it sort of dissolves and disappears - this is the "work" of lysosomes.
All cells contain small rounded bodies - ribosomes. They provide assembly of complex protein molecules.
As a result of the breakdown of nutrients that have entered the cell, energy is released. This energy, necessary for life processes, accumulates in mitochondria.
animal cage
In plant cells there are special organelles characteristic only for them - plastids. There are three types of plastids. In colorless, reserve nutrients accumulate, for example, starch in potato tubers. Red-yellow contain compounds that provide a variety of colors for flowers and fruits of plants. Green plastids, or chloroplasts, contain pigment chlorophyll, giving leaves and young stems of plants green color. In chloroplasts, with the help of sunlight energy, they form organic matter- carbohydrates.
An essential part of a plant cell is vacuole. This is a large vesicle filled with cell sap, the composition of which differs from the surrounding cytoplasm.
In the cytoplasm of cells near the nucleus is cell center. In the cells of animals and lower plants, it includes centrioles. The cell center takes part in cell division.
plant cell
The most important part of the cell core. It is usually located in the center of the cell. However, in plant cells, the inner part is usually occupied by a large vacuole, so the nucleus is located near the cell membrane. The nucleus contains one or more nucleoli. The nucleus stores hereditary information about a given cell and about the organism as a whole. This information is "recorded" in molecules nucleic acid, which is part of chromosomes(from the Greek "chrome" - color, "soma" - body). Chromosomes become clearly visible during cell division.
It has been established that all cells of the body of animals and higher plants have a double set of chromosomes, it is customary to designate it 2 n. The only exceptions are germ cells, in which the set of chromosomes is single, therefore it is denoted by one letter n. The number of chromosomes for each type of organism is constant and does not depend on the level of its organization. So, a person has 46 chromosomes, a chicken has 78, a sheep has 54, a chimpanzee has 48, a rye has 14, an oak has 24. In cells, chromosomes of the same structure and size form pairs. Chromosomes of one pair are called homologous (from the Greek "homology" - correspondence, agreement).
Outside the host cell, viruses do not show signs of life and behave like ordinary chemical compounds.
Phagocytosis
Phagocytosis(from the Greek "phageo" - to devour, "cytosis" - a cell) - absorption by a cell of large molecules of organic substances and even whole cells. The plasma membrane is directly involved in this process. Many protozoa feed on phagocytosis. In vertebrates, only a few cells retained the ability to phagocytosis. For example, in humans, these are white blood cells - leukocytes. Capturing and "devouring" pathogens, they protect us from dangerous infections.
pinocytosis(from the Greek "pino" - to drink) - the capture and absorption of liquid and substances dissolved in it by the cell.
Tobacco mosaic virus
Leaf infected with tobacco mosaic virus
Bacteriophage is a virus of bacteria
Human adenovirus causes colds and flu
Tobacco mosaic virus is being used to create bright colors in some new tulip varieties.
pinocytosis
Questions and tasks
1. What parts are required for the cells of all living organisms? Why?
2. Remember what science studies the structure and functions of cells.
3. What is the plasma membrane, what is its significance?
4. What is the essence of phagocytosis? Explain why phagocytosis is not possible in a plant cell.
5. What is the role of ribosomes in the body?
6. How is the structure of the endoplasmic reticulum related to the functions it performs?
7. After reading the text, explain how the Golgi apparatus and lysosomes are related.
8. Remembering the properties of living things, explain why a cell that does not have mitochondria and ribosomes cannot exist.
9. Potato tuber turns green in the light. With the transformation of what organelles in the cell is this associated?
10. Tell us about the meaning of the cell nucleus.
11. What are chromosomes? What is their role in the cell? How many chromosomes does a person have?
12. Make and fill in the table "Organoids and their functions."
13. Make a table "Comparison of the structure of plant and animal cells" (work in small groups).
14. Why do viruses need a cell to live?
15. Predict if a gauze bandage can fully protect against airborne viral infections and why.
Laboratory work
Do activity 3 on p. 13–15 (Laboratory work).
Work with computer
The cell is complete system. Mandatory parts of the cell are: the membrane, the cytoplasm and the genetic apparatus (in nuclear organisms, this is the nucleus). All organisms according to the structure of the cell are divided into two groups - pre-nuclear (non-nuclear) and nuclear. Viruses do not have cellular structure. Chromosomes are carriers hereditary information.
2. Cell division*
Division is the most important property of cells; without it, the growth and development of multicellular organisms, the replacement and restoration of individual cells, tissues, or even entire organs would be impossible. Think about how a lizard's tail grows back after she's shed a predator, or how a wound on your skin heals after a cut. Cell division underlies the reproduction of organisms.
There are two main types of division - mitosis (from the Greek "mitos" - thread) and meiosis (from the Greek "meiosis" - reduction). As a result mitosis From one mother cell, two daughter cells are formed. In this case, the number of chromosomes in both daughter cells is the same as in the mother cell, that is, the daughter and mother cells are the same.
As a result meiosis not two, but four cells are formed, each of which has half the number of chromosomes compared to the mother cell.
Chromosomes play an important role in the process of cell division: they ensure the transmission of hereditary information from generation to generation.
Mitosis
In the period between divisions (and it can last up to 20 hours in plant and animal cells), the cell grows and prepares for a new division. At this time, many proteins are formed in it, the most important organelles double. Chromosomes also double: now each consists of two daughter chromosomes, or chromatids. There are four successive phases of mitosis; their total duration is different for different organisms, to a greater extent it depends on external conditions, in particular on temperature. This is how mitosis proceeds in an animal cell.
1. Centrioles diverge towards the poles of the cell; division spindles appear; chromosomes are clearly visible, it is clear that they are double; the nuclear membrane dissolves, the nucleolus disappears.
2. Chromosomes are located along the equator of the cell, attached to the threads of the spindle of division.
3. Chromatids (daughter chromosomes) diverge to the poles of the cell due to division spindles.
4. Spindles of division disappear; nuclear membranes are formed around the separated chromosomes; the cytoplasm divides; daughter cells are formed.
Chromosomes move to the poles of the cell
Meiosis in an animal cell
Meiosis consists of two consecutive divisions, but chromosome duplication occurs only once, before the first division. Therefore, the resulting cells contain half the set of chromosomes compared to the original cell ( n).
I division
Chromosome duplication occurs before the first division
1. Chromosomes are clearly visible. Homologous chromosomes form pairs, closely adhering to each other and twisting along their entire length.
Each chromosome is made up of two chromatids.
Homologous chromosomes exchange regions and separate.
2. Pairs of homologous chromosomes line up along the equator.
3. Homologous chromosomes, consisting of two chromatids, diverge towards the poles. The divergence of each pair occurs independently of the chromosomes of other pairs.
4. Daughter cells are formed with a halved number of chromosomes, each of which consists of two chromatids.
II division
Chromosome doubling does not occur
1. Chromosomes are visible, the nuclear envelope is destroyed. The nucleus disappears. Fission spindles are formed.
2. Chromosomes line up along the equator, attach to the spindle threads.
3. Chromatids of chromosomes in both daughter cells diverge towards the poles.
4. Four cells are formed with a single set of chromosomes. These cells form germ cells.
When the germ cells merge, the number of chromosomes in the newly formed cell is restored.
Questions and tasks
1. What is the role of cell division in the life of organisms?
2. Name the main types of cell division.
3. What is mitosis?
4. What happens in a cell before division?
5. Where are the chromosomes located?
6. What is a chromatid?
7. What is meiosis?
8. Select criteria for comparing the processes of mitosis and meiosis. Discuss them with classmates and make a table.
9. What is the biological role of mitosis and meiosis?
10. Give examples of phenomena that are explained by cell division.
Work with computer
Refer to the electronic application. Study the material of the lesson and complete the suggested tasks.
Cell division is the basis of growth, reproduction and individual development organisms. Meiosis is associated with reproduction, as a result of which cells with a single set of chromosomes are formed: in animals - germ cells, and in plants - spores. As a result of mitosis, daughter cells have the same set of chromosomes as the mother.
3. Tissues of plants and animals
You already know that all living organisms are divided into two large groups according to their structure - unicellular and multicellular. The bodies of unicellular organisms consist of a single cell in which all life processes take place.
The situation is different in multicellular organisms. Their bodies are made up of many different cells. For example, there are more than 100 trillion cells in the human body. Each cell of a multicellular organism has its own "specialty", that is, it performs a strictly defined function - work. Some serve as a support for the body, others provide the movement of substances, digestion, reproduction of the body, and many other functions.
A group of cells that are similar in size, structure and functions forms textile. Cells of the same tissue are interconnected intercellular substance.
Let's look inside the plant and see how its tissues are arranged.
Here we have the tips of the root and shoot. They are formed by small, constantly dividing cells with large nuclei; there are no vacuoles at all in their cytoplasm. This educational cloth, the division of its cells ensures the growth of the plant. For example, the embryo of a plant consists entirely of it.
Protect plants from adverse effects, from damage covering tissues. They are formed by both living and dead cells. Thick and durable shells of dead cells do not let water or air through. They are very strongly connected to each other. This covering tissue is called cork. It is well developed on tree trunks.
The skin consists of living cells - the integumentary tissue of leaves and young stems.
Perform integumentary tissues and other functions: through special education- stomata and lenticels - plants breathe, evaporate water. The skin of the leaf secretes a waxy substance that prevents excessive evaporation of water from its surface in hot weather.
unicellular organisms
Animal cells
plant cells
Plant tissues
Gives support to the plant and its organs mechanical fabric. Its cells have thickened, lignified shells, and living content is often absent in them. You can get an idea of the strength of a mechanical tissue by breaking a walnut shell, an apricot pit - they contain special stony cells. And in the stem, the supporting role is played by elongated cells - mechanical fibers.
Water, minerals and organic substances dissolved in it move along conductive tissues. Conductive tissue cells can be either living or dead. The bast, which conducts organic substances, consists of living cells. From the dead - wood, conducting water with minerals. Cells of bast and wood outwardly resemble tubules. The strands of these tissues (conductive bundles) go throughout the plant - from the root to the stem and leaves.
The pulp of leaves and fruits, the soft parts of the flower, the main mass of the bark and core of the stems, the root forms main fabric. Its functions are very diverse. The cells of the leaf pulp contain chloroplasts- organelles that are involved in the formation of nutrients during photosynthesis (photosynthetic basic tissue). Many parts of the plant body accumulate nutrients (storage basic tissue).
Animal tissues
Now consider the structural features of the tissues of animal organisms. There are four types of animal tissues - epithelial, connective, muscle and nervous.
The outer surface of the body of animals, as well as the cavities of internal organs, for example, the oral cavity, the cavity of the stomach, intestines, is lined epithelial tissue. Its cells are very tightly adjacent to each other, and the intercellular substance is almost absent. This structure protects the underlying tissues from drying out, penetration of microbes, and mechanical damage. When damaged, epithelial cells are quickly replaced by new ones. Epithelial tissue is also involved in the formation of glands - salivary, sweat, pancreas, liver and others, which form substances important for the body.
The supporting and protective function in the body of animals is performed by connective tissue. It also largely determines the shape of their body, can serve as an energy depot and protect the body from heat loss. This type includes bone tissue, cartilage, adipose tissue, blood and others. Despite the great diversity, all types of connective tissue are united by one feature - the presence of a large amount of intercellular substance. It can be dense, like in bone tissue, loose, like in tissues that fill the space between organs, and liquid, like in blood.
An important feature of animals is their ability to move. The movement of most animals is the result of muscle contractions. Muscles are made up of muscle tissue. Distinguish between smooth and striated muscle tissue. Their main property is excitability and contractility.
Cells of smooth muscle tissue are mononuclear; they contract very slowly, but can remain contracted for a long time. It is smooth muscles that ensure the prolonged closing of the shells of molluscs, the narrowing and expansion of blood vessels in humans.
The striated muscle consists of multinucleated cells that have a striated striation, hence the name of the tissue. It is with their contractions that the rapid movements of numerous arthropods (insects, crayfish, spiders) and vertebrates are associated. Remember the swift flight of a dragonfly, swallows, the running of an antelope, a cheetah!
A striated muscle can instantly contract - a thousand times faster than a smooth one.
nervous tissue forms nervous system animal. It is based on nerve cells. Any nerve cell has a body and numerous processes of various lengths. One of them is usually especially long, it can reach a length of several centimeters to several meters, like, for example, a giraffe. Basic properties nerve cell are excitability and conduction.
The embryo of a plant consists entirely of educational tissue. As it develops, most of it is transformed into other types of tissues, but even in the oldest tree, educational tissue remains: it is preserved on the tops of all shoots, in all buds, at the tips of roots, in the cambium - cells that ensure the growth of the tree in thickness.
In the embryos of all vertebrates, the skeleton consists of cartilage, which is replaced by bone tissue as it develops. The exceptions are sharks and rays - their skeleton remains cartilaginous until the end of their lives.
Muscle tissues contain a large number of parallel contractile fibers. It is their contraction, in which they become shorter and thicker, that allows the muscle to perform mechanical work.
Questions and tasks
1. What is fabric? List four types of animal tissue and five types of plant tissue.
2. Look at the picture. Prove that it does not contradict the information that there are four types of animal tissue.
3. What tissues are connective?
4. Name the features of the structure of epithelial tissue.
5. What tissue provides plant growth?
6. What tissue does a potato tuber consist of?
7. Using the text and drawings of the paragraph, draw up the schemes “Classification of plant tissues” and “Classification of animal tissues”.
8. What is blood?
9. What are the main properties of muscle tissue?
10. How are nerve cells arranged?
11. What are the structural features of the educational tissue of plant organisms?
12. In what parts of the plant is the educational tissue?
13. What tissue provides support for the body of the plant and its organs?
14. Name the tissue along which water, mineral salts and organic substances move in plants.
15. How are the structural features of tissues related to the functions they perform?
16. What is the importance of cell specialization for a multicellular organism?
Laboratory work
Do activity 5 on p. 17–18 and 6 on p. 19–20 (Laboratory work).
Work with computer
Refer to the electronic application. Study the material of the lesson and complete the suggested tasks.
Tissue is a group of cells that are similar in size, structure, and function. Tissue cells are interconnected by intercellular substance. In plants, educational, basic, integumentary, mechanical and conductive tissues are distinguished, in animals - epithelial, connective, muscle and nervous tissues.
Sixth graders on lessons biology there are many important things to learn, such as photosynthesis and how exactly it can affect human life. They will also have the opportunity to see an animal cell in a section under a microscope. But here with independent work there may be hitches, in the solution of which the solution to the textbook will help "Biology. Workbook Grade 6" Sonin. Publishing House Bustard, 2017
What is included in it.
One hundred and seventy exercises are distributed on one hundred and one pages of the manual. Detailed laboratory workshops will help to better understand the thematic sections. A training tasks V GDZ in biology Grade 6 Sonin designed to provide support on the way to overcome various difficulties.
Do you need a solver?
Botany has many tricky aspects, which are quite difficult to figure out alone. Especially when the teacher does not always have enough time in the classroom to explain all the material. Yes, and parents by and large try not to delve into the d / s in this subject, preferring to pay attention to the main disciplines. Handbook for the textbook "Biology. Workbook (with a bee) Grade 6" Sonin is a good help for schoolchildren, thanks to a detailed and thorough presentation of information.
- Sixth grade biology is the beginning of acquaintance with the kingdoms of living organisms. Students will learn a lot about fungi, protozoa and plants, and will gain basic skills and concepts that will help them further study the course of the discipline. In order for training to be as effective and efficient as possible, high-quality study guides. One of the common ones recommended by biology teachers is workbook in biology for the 6th grade, the author of which is Sonin N.I.
- What attracts this particular collection (it is also called the “notebook with a bee”)? It's colorful, according to needs, age characteristics 10-12-year-old teenagers designed and compiled edition, in which:
- worked out almost all the topics of the standard textbook;
- interesting and unusual tasks are offered, instilling interest and love for biology;
- exercises are ranked according to their level of difficulty. - If the task cannot be completed, and the student is not able to get help from the teacher for one reason or another, they will help GDZ to the allowance. They give complete and objective answers to all questions and tasks of the notebook. Such a solution book will become a faithful assistant for those for whom Sonin's manual is not the main workbook, but is used as a collection for self-study biology.
- The difficult discipline of biology with competently organized process learning and using interesting and effective literature can seriously captivate and interest a student. It is advisable to entrust the choice of training materials to experienced specialists - in this case, the effect and result of the classes will be significantly higher. To find quality educational materials and solutions for them, you need experience and knowledge of the features of the presented basic and additional sources in biology.
- Studying such collections and using GDZ to them, already from the middle school, students can be instilled with a good habit:
- competent selection and study of subject literature;
- assessment and analysis of the proposed tasks, comparison of information with their own goals and objectives. For example, for those who are preparing to participate in subject Olympiads and competitions in biology, materials containing tasks are needed. advanced level difficulties;
- remembering the technology of recording the correct answer to questions and tasks. An illiterate entry is often not counted, even if the solution is given correctly. Since correctly recorded results are given in the collections of ready-made homework assignments, students automatically remember this order and do not make annoying mistakes. - Among useful and interesting practical sources for sixth graders, many experts name biology workbooks for grade 6 compiled by N. I. Sonin - (with a bee), they were so named because of the bee depicted on the cover of the book. The main difference between such collections is a good systematization of the material, high-quality illustrations and a variety of multi-level tasks and exercises. Another plus is versatility, the ability to use this workbook complete with various basic sixth grade biology textbooks. Among the tasks of the manual:
- compilation and analysis of tables;
- biological crosswords;
- tasks for observation and determination of patterns;
- finding signs or, according to individual signs - phenomena and processes, similarities and differences. - Placed at the end of each section, the heading "Training sessions" allows sixth graders to independently check the level of their knowledge and degree of preparedness on topics and sections, instills valuable skills of self-control and self-examination.
