1. All leaves have veins. What structures are they formed from? What is their role in the transport of substances throughout the plant?
The veins are formed by vascular-fibrous bundles that penetrate the entire plant, connecting its parts - shoots, roots, flowers and fruits. They are based on conductive tissues, which carry out the active movement of substances, and mechanical ones. Water and minerals dissolved in it move in the plant from the roots to the above-ground parts through the vessels of the wood, and organic substances move through the sieve tubes of the bast from the leaves to other parts of the plant.
In addition to conductive tissue, the vein contains mechanical tissue: fibers that give the leaf plate strength and elasticity.
2. What is the role of the circulatory system?
Blood carries nutrients and oxygen throughout the body, and removes carbon dioxide and other waste products. Thus, the blood performs the respiratory function. White blood cells perform a protective function: they destroy pathogens that enter the body.
3. What does blood consist of?
Blood consists of a colorless liquid - plasma and blood cells. There are red and white blood cells. Red blood cells give blood its red color because they contain a special substance - the pigment hemoglobin.
4. Offer simple circuits closed and open circulatory systems. Point out the heart, blood vessels and body cavity.
Scheme of an open circulatory system
5. Offer an experiment that proves the movement of substances throughout the body.
Let us prove that substances move throughout the body using the example of a plant. Let's put a young shoot of a tree in water tinted with red ink. After 2-4 days, take the shoot out of the water, wash off the ink from it and cut off a piece of the lower part. Let us first consider a cross section of the shoot. The cut shows that the wood has turned red.
Then we cut along the rest of the shoot. Red stripes appeared in areas of stained vessels that are part of the wood.
6. Gardeners propagate some plants using cut branches. They plant the branches in the ground and cover them with a jar until they are completely rooted. Explain the meaning of the jar.
Under the can, high constant humidity is formed due to evaporation. Therefore, the plant evaporates less moisture and does not wither.
7. Why do cut flowers fade sooner or later? How can you prevent their rapid decline? Make a diagram of the transport of substances in cut flowers.
Cut flowers are not a full-fledged plant, because they have had the horse system removed, which ensured adequate (as intended by nature) absorption of water and minerals, as well as part of the leaves, which ensured photosynthesis.
The flower withers mainly because there is not enough moisture in the cut plant or flower due to increased evaporation. This begins from the moment of cutting and especially when the flower and leaves have been without water for a long time and have a large evaporation surface (cut lilac, cut hydrangea). Many greenhouse cut flowers find it difficult to tolerate the difference between the temperature and humidity of the place where they were grown and the dryness and warmth of living rooms.
But a flower can fade or grow old, this process is natural and irreversible.
To avoid fading and extend the life of flowers, a bouquet of flowers should be in a special package that serves to protect against crushing, penetration sun rays, warmth of hands. On the street, it is advisable to carry the bouquet with the flowers facing down (moisture will always flow directly to the buds while the flowers are being transferred).
One of the main reasons for flowers wilting in a vase is a decrease in the sugar content in the tissues and dehydration of the plant. This happens most often due to blockage of blood vessels by air bubbles. To avoid this, the end of the stem is immersed in water and an oblique cut is made with a sharp knife or pruning shears. After this, the flower is no longer removed from the water. If such a need arises, the operation is repeated again.
Before placing cut flowers in water, remove all lower leaves from the stems, and also remove thorns from roses. This will reduce the evaporation of moisture and prevent the rapid development of bacteria in the water.
8. What is the role of root hairs? What is root pressure?
Water enters the plant through root hairs. Covered with mucus, in close contact with the soil, they absorb water with minerals dissolved in it.
Root pressure is the force that causes one-way movement of water from roots to shoots.
9. What is the significance of water evaporation from leaves?
Once in the leaves, water evaporates from the surface of the cells and exits into the atmosphere in the form of steam through the stomata. This process ensures a continuous upward flow of water through the plant: having given up water, the cells of the leaf pulp, like a pump, begin to intensively absorb it from the vessels surrounding them, where water enters through the stem from the root.
10. In the spring, the gardener discovered two damaged trees. In one, mice partially damaged the bark; in another, hares gnawed a ring on the trunk. Which tree can die?
A tree whose trunk has been gnawed by hares may die. As a result, the inner layer of bark, called the bast, will be destroyed. Solutions of organic substances move through it. Without their influx, cells below the damage will die.
The cambium lies between the bark and wood. In spring and summer, the cambium divides vigorously, resulting in new phloem cells being deposited toward the bark and new wood cells toward the wood. Therefore, the life of the tree will depend on whether the cambium is damaged.
Question 1.
To maintain normal functioning, the body needs nutrients (minerals, water, organic compounds) and oxygen. Typically, these substances move through vessels (through the vessels of wood and bast in plants and through the blood vessels of animals). In cells, substances move from organelle to organelle. Substances are transported into the cell from the intercellular substance. Waste and unnecessary substances are removed from the cells and then through the excretory organs from the body. Thus, the transport of substances in the body is necessary for normal metabolism and energy.
Question 2.
In unicellular organisms, substances are transported by the movement of the cytoplasm. So, in an amoeba, the cytoplasm flows from one part of the body to another. The nutrients contained in it move and are distributed throughout the body. In the slipper ciliate - a single-celled organism with a constant body shape - the movement of the digestive vesicle and distribution nutrients throughout the cell is achieved by continuous circular movement of the cytoplasm.
Question 3.
Cardiovascular the system ensures continuous blood movement, which is necessary for all organs and tissues. Through this system, organs and tissues receive oxygen, nutrients, water, mineral salts, and hormones that regulate the functioning of the body are supplied to the organs with blood. Carbon dioxide, decay products, enters the blood from organs. In addition, the circulatory system maintains a constant body temperature and ensures a constant internal environment of the body ( homeostasis), the relationship of organs, ensures gas exchange in tissues and organs. The circulatory system also performs a protective function, since the blood contains antibodies and antitoxins.
Question 4.
Blood- it's liquid connective tissue. It consists of plasma and formed elements. Plasma is a liquid intercellular substance, formed elements are blood cells. Plasma makes up 50-60% of blood volume and is 90% water. The rest is organic (about 9.1%) and inorganic (about 0.9%) plasma substances. Organic substances include proteins (albumin, gamma globulin, fibrinogen, etc.), fats, glucose, urea. Due to the presence of fibrinogen in plasma, blood is capable of clotting - an important protective reaction that saves the body from blood loss.
Question 5.
Blood consists of plasma and formed elements. Plasma is a liquid intercellular substance, formed elements are blood cells. Plasma makes up 50-60% of blood volume and is 90% water. The rest is organic (about 9.1%) and inorganic
(about 0.9%) plasma substances. Organic substances include proteins (albumin, gamma globulin, fibrinogen, etc.), fats, glucose, urea. Due to the presence of fibrinogen in plasma, blood is capable of clotting - an important protective reaction that saves the body from blood loss.
The formed elements of blood are erythrocytes - red blood cells, leukocytes - white blood cells and platelets - platelets.
Question 6.
Stomata represent a gap that is located between two bean-shaped (guard) cells. Guard cells are located above the large intercellular in loose leaf tissue. Stomata are usually located on the lower side of the leaf blade, and in aquatic plants (water lily, egg capsule) - only on the upper side. A number of plants (cereals, cabbage) have stomata on both sides of the leaf.
Question 7.
To maintain normal life functions, the plant absorbs CO 2 (carbon dioxide) from the atmosphere with its leaves and water with mineral salts dissolved in it from the soil with its roots.
Plant roots are covered, like fluff, with root hairs that absorb soil solution. Thanks to them, the suction surface increases tens and even hundreds of times.
The movement of water and minerals in plants is carried out due to two forces: root pressure and evaporation of water by leaves. Root pressure is a force that causes a one-way supply of moisture from roots to shoots. Evaporation of water by leaves is a process that occurs through the stomata of leaves and maintains a continuous flow of water with minerals dissolved in it throughout the plant in an upward direction.
Question 8.
Organic substances synthesized in the leaves flow into all organs of the plant through the sieve tubes of the phloem and form a downward current. In woody plants, the movement of nutrients in the horizontal plane occurs with the participation of medullary rays.
Question 9.
With the help of root hairs, water and minerals are absorbed from soil solutions. The cell membrane of root hairs is thin - this facilitates absorption.
Root pressure- a force that causes a one-way supply of moisture from roots to shoots. Root pressure develops when the osmotic pressure in the root vessels exceeds the osmotic pressure of the soil solution. Root pressure, along with evaporation, is involved in the movement of water in the plant body.
Question 10.
The evaporation of water by a plant is called transpiration. Water evaporates through the entire surface of the plant's body, but especially intensely through the stomata in the leaves. The meaning of evaporation: it takes part in the movement of water and solutes throughout the body of the plant; promotes carbohydrate nutrition of plants; protects plants from overheating.
Answers to tickets for biology 2006 9th grade
Ticket#1
1. No. 1. The relationship between plastic and energy metabolism
The constant interaction of every living organism with its environment. Absorption from environment some substances and the release of waste products into it. Metabolism between the body and the environment - main feature alive. Absorption of inorganic substances and sunlight energy by plants and some bacteria from the environment, using them to create organic substances. The absorption of oxygen by plants and animals from the environment during respiration and the release of carbon dioxide. Obtaining organic substances and the energy stored in them from the environment by animals, fungi, most bacteria, and humans.
2. The essence of exchange. Metabolism and energy conversion in a cell is a set of chemical reactions of the formation of organic substances using energy and the breakdown of organic substances with the release of energy.
3. Plastic metabolism - a set of reactions for the synthesis of organic substances from which cell structures are formed, its composition is updated, and enzymes necessary to accelerate chemical reactions in the cell are synthesized. The synthesis of a complex organic substance - protein - from less complex organic substances - amino acids - is an example of plastic metabolism. The role of enzymes in accelerating chemical reactions, the use of energy for the synthesis of organic substances released in the process of energy metabolism.
4. Energy metabolism - the breakdown of complex organic substances (proteins, fats, carbohydrates) into simple substances(ultimately to carbon dioxide and water) with the release of energy used in life processes. Breathing is an example of energy exchange, during which oxygen entering the cell from the air oxidizes organic substances and, at the same time, energy is released. Participation in the energy metabolism of enzymes that were synthesized in the process of plastic metabolism, in accelerating the oxidation reactions of organic substances.
5. The relationship between plastic and energy metabolism: plastic exchange supplies organic substances and enzymes for energy metabolism, and energy metabolism supplies plastic energy, without which synthesis reactions cannot occur. Violation of one type of cellular metabolism leads to disruption of all vital processes and to the death of the body.
No. 2. Increasing complexity of plant organization in the process of evolution. Reasons for evolution
1. Algae. Single-celled algae are the most simply organized plants. The appearance as a result of variability and heredity of multicellular algae, the preservation of individuals with this useful feature by natural selection.
2. The origin of more complex plants - psilophytes - from ancient algae, and from them - mosses and ferns. The appearance of organs in mosses - stems and leaves, and in ferns - roots and a more developed conducting system.
3. Origin from ancient ferns due to heredity and variability, the action of natural selection of more complex plants of ancient gymnosperms, in which the seed appeared. Unlike a spore (one specialized cell from which a new plant develops), a seed is a multicellular formation that has a formed embryo with a supply of nutrients and is covered with a dense skin. The likelihood of a new plant emerging from a seed is much greater than from a spore that has a small supply of nutrients.
4. The origin of more complex plants from ancient gymnosperms - angiosperms, which developed flowers and fruits. The role of the fruit is to protect the seed from unfavorable conditions and increase the likelihood of their widespread distribution in nature.
5. The complication of the structure of plants from algae to angiosperms over many millennia due to the ability to change, to transmit changes by inheritance and due to the action of natural selection.
No. 3. Determining the magnification of a school microscope, preparing it for work
The magnification of a school microscope is determined by multiplying the numbers on the lens and eyepiece indicating their magnification. To work with a microscope, you need to place it with a tripod facing you, point the light at the opening of the stage with a mirror, place a microspecimen on the table, secure it with clamps, lower the tube down without damaging the microspecimen, and then, looking through the eyepiece, slowly lift the tube to obtain a clear image.
Ticket 2.
No. 1. Respiration of organisms, its essence and meaning.
1. The essence of respiration is the oxidation of organic substances in cells with the release of energy necessary for vital processes. The supply of oxygen necessary for respiration into the body cells of plants and animals: in plants through stomata, lentils, cracks in the bark of trees; in animals - through the surface of the body (for example, in earthworm), through the respiratory organs (trachea in insects, gills in fish, lungs in terrestrial vertebrates and humans). Transport of oxygen in the blood and its entry into the cells of various tissues and organs in many animals and humans. 2. Participation of oxygen in the oxidation of organic substances to inorganic ones, releasing energy obtained from food and using it in all life processes. The absorption of oxygen by the body and the removal of carbon dioxide from it through the body surface or respiratory organs is gas exchange. 3. The relationship between the structure and functions of the respiratory organs. The adaptability of the respiratory organs, for example in animals and humans, to perform the functions of absorbing oxygen and releasing carbon dioxide: an increase in the volume of the lungs of humans and mammals due to the huge number of pulmonary vesicles penetrated by capillaries, an increase in the surface of contact of blood with air, and thereby an increase in the intensity of gas exchange . The adaptability of the structure of the walls of the respiratory tract to the movement of air during inhalation and exhalation, cleaning it from dust (ciliated epithelium, the presence of cartilage). 4. Gas exchange in the lungs. Exchange of gases in the body by diffusion. The entry into the lungs through the arteries of the pulmonary circulation of venous blood containing a small amount of oxygen and a large amount of carbon dioxide. Penetration of oxygen into the plasma of venous blood from the pulmonary vesicles and capillaries by diffusion through their thin walls, and then into the red blood cells. The formation of a fragile compound of oxygen with hemoglobin - oxyhemoglobin. Constant saturation of the blood plasma with oxygen and the simultaneous release of carbon dioxide from the blood into the air of the lungs, the transformation of venous blood into arterial blood. 5. Gas exchange in tissues. The flow of arterial, oxygenated and carbon dioxide-poor blood into the tissue through the systemic circulation. The flow of oxygen into the intercellular substance and body cells, where its concentration is much lower than in the blood. Simultaneous saturation of the blood with carbon dioxide, converting it from arterial to venous. Transport of carbon dioxide, which forms a weak compound with hemoglobin, into the lungs.
2. Plant kingdom. The structure and vital activity of plants, their role in nature and human life
1. Characteristics of the plant kingdom. Diversity of plants: algae, mosses, ferns, gymnosperms, angiosperms (flowering plants), their adaptability to different environmental conditions. General features of plants: they grow all their lives, practically do not move from one place to another. The presence in the cell of a durable membrane made of fiber, which gives it its shape, and vacuoles filled with cell sap. The main feature of plants is the presence of plastids in their cells, among which the leading role belongs to chloroplasts containing the green pigment - chlorophyll. The method of nutrition is autotrophic: plants independently create organic substances from inorganic ones using solar energy(photosynthesis).
2. The role of plants in the biosphere. The use of solar energy to create organic substances through the process of photosynthesis and the release of oxygen necessary for the respiration of all living organisms. Plants are producers of organic matter, providing themselves, as well as animals, fungi, most bacteria and humans with food and the energy contained in it. The role of plants in the cycle of carbon dioxide and oxygen in the atmosphere.
No. 3. Consider the finished microspecimen of a protozoan and name its type.
Volvox Volvox globator (can be replaced with another micropreparation)
Volvox is a multicellular spherical colony consisting of a large number of flagellated unicellular individuals included in the gelatinous substance and interconnected by cytoplasmic bridges. Each individual has two flagella. Daughter colonies are visible inside the Volvox.
Ticket No. 3
Transport of substances in living organisms.
1. Movement of water and minerals in the plant. Absorption of water and minerals by root hairs located in the root absorption zone. Movement of water and minerals through vessels - conductive tissue of the root, stem, leaf. Vessels are long hollow tubes formed by one row of cells, between which transverse partitions have dissolved. 2. Root pressure is the force by which water and minerals move up the stem and into the leaves. The role of root pressure in the movement of water and minerals from root vessels into veins and then into leaf cells. Veins are vascular-fibrous bundles of the leaf. Evaporation of water by leaves due to the continuous movement of water from the roots up to the leaves. Stomata are slits limited by two guard cells, their role in the evaporation of water: periodic opening and closing depending on environmental conditions. 3. The suction force resulting from the evaporation of water and root pressure are the reasons for the movement of minerals in the plant. The path of water from the root to the leaves is an upward current. Short rising current herbaceous plants, long - near the trees. The movement of water and minerals in spruce to a height of up to 30 m, in eucalyptus - up to 100 m. An experiment with a cut branch placed in water tinted with ink is proof of the movement of water through the vessels of wood. 4. Movement of organic substances in the plant. The formation of organic substances in plant cells with chloroplasts during photosynthesis. Their use by all organs in the process of life: growth, breathing, movement. The movement of organic substances through sieve tubes - living thin-walled elongated cells connected by narrow ends riddled with pores. Tree bark, the presence of bast with bast fibers and sieve tubes. The movement of organic substances from leaves to all organs is a downward current. An experiment with a ringed branch placed in a vessel with water is evidence of the movement of organic substances through the sieve tubes of the bast. 5. The movement of blood in the human body through two circles of blood circulation - large and small. Blood flows through a large circle to the cells of the body, and through a small circle into the lungs. 6. Systemic circulation. The pushing of oxygenated arterial blood from the left ventricle of the heart into the aorta, which branches into arteries. The blood flows through them into the capillaries - the smallest vessels with many holes. The release of oxygen by capillaries to the cells of the body and the entry of carbon dioxide from the cells into the capillaries. Saturation of blood in capillaries with carbon dioxide, turning it into venous. Movement of venous blood through the veins into the right atrium. 7. Pulmonary circulation. The pushing of venous blood from the right ventricle into the pulmonary artery, which branches into many capillaries intertwining the pulmonary vesicles. Diffusion of oxygen from the pulmonary vesicles into the capillaries - the conversion of venous blood into arterial blood. The entry of carbon dioxide from the capillaries into the pulmonary vesicles by diffusion. Removing carbon dioxide from the body when exhaling. The return of oxygenated arterial blood through the veins of the pulmonary circulation to the left atrium.
Question 2 Complication organization of chordates in the process of evolution. Reasons for evolution.
1. The first chordates. Cartilaginous and bony fish. The ancestors of chordates are bilaterally symmetrical animals similar to annelids. Active lifestyle of the first chordates. The origin of two groups of animals from them: sedentary (including the ancestors of modern lancelets) and free-swimming, with a well-developed spine, brain and sense organs. Origin from ancient free-swimming chordate ancestors of cartilaginous and bony fishes.
2. More high level organization of bony fish compared to cartilaginous fish: the presence of a swim bladder, a lighter and stronger skeleton, gill covers, a more advanced method of respiration, which allowed bony fish to spread widely in fresh water bodies, seas and oceans.
3. The origin of ancient amphibians. One of the groups of ancient bony fishes is lobe-finned fish. As a result of hereditary variability and the action of natural selection, the formation of dissected limbs in lobe-finned fish, adaptations to air breathing, and the development of a three-chambered heart. Origin from lobe-finned fishes of ancient amphibians.
4. The origin of ancient reptiles. The habitat of ancient amphibians is wet places, the banks of reservoirs. Penetration into the interior of the land by their descendants - ancient reptiles, which acquired adaptations for reproduction on land; instead of the mucous glandular skin of amphibians, a horny cover was formed, protecting the body from drying out.
5. Origin of birds and mammals. Ancient reptiles are the ancestors of ancient higher vertebrates - birds and mammals. Signs of their higher organization: a highly developed nervous system and sensory organs; four-chamber heart and two circulation circles, eliminating the mixing of arterial and venous blood, more intense metabolism; highly developed respiratory system; constant body temperature, thermoregulation, etc. The development of primates, from which man descended, is more complex and progressive among mammals.
Ticket number 3 question 3.
Prepare and examine a microscopic specimen (skin of onion scales or elodea leaf) under a microscope. Draw a cell and label its parts.
Apply 2-3 drops of iodine-tinted water to a glass slide. The sample is usually taken as a very thin transparent layer or section; it is placed on a rectangular glass plate, called a slide, and covered on top with a thinner, smaller glass plate, called a coverslip. The sample is often stained with chemicals to increase contrast. The glass slide is placed on the stage so that the sample is located above the central hole of the stage. The cell is sketched schematically. (Onion skins have no chloroplasts)
Ticket 4.
No. 1. Chemical composition of the cell. The role of water and inorganic substances in the life of a cell.
1. Elementary composition of the cell. Similarities chemical composition cells of different organisms as evidence of their relationship. Basic chemical elements components of the cell: oxygen, carbon, hydrogen, nitrogen, potassium, sulfur, phosphorus, chlorine, magnesium, sodium, calcium, iron.
2. The role of various chemical elements in the cell. Oxygen, carbon, hydrogen and nitrogen are the main chemical elements that make up the molecules of organic substances. Elements such as potassium, sodium and chlorine are part of the blood plasma, participate in metabolism and ensure the constancy of the internal environment of the body - homeostasis.
Sulfur is an element that is part of some proteins, phosphorus is part of all nucleic acids, magnesium is chlorophyll, iron is hemoglobin (hemoglobin is a protein that is part of red blood cells and ensures the transport of oxygen and carbon dioxide in the body), calcium - bones, shells shellfish
3. Chemical substances that make up the cell: inorganic (water, mineral salts) and organic (carbohydrates, fats, proteins, nucleic acids, ATP).
4. Mineral salts, their role in the cell. The content of mineral salts in the cell in the form of cations (K+, Na+, Ca2+, Mg2+) and anions (-HPO|~, -H2PC>4, -SG, -HCS*z). The balance of the content of cations and anions in the cell, ensuring the constancy of the internal environment of the body. Examples: in the cell the environment is slightly alkaline, inside the cell there is a high concentration of K+ ions, and in the environment surrounding the cell there is a high concentration of Na+ ions. Participation of mineral salts in metabolism.
Ensuring cell elasticity. The consequences of cell loss of water are wilting of leaves, drying out of fruits;
Acceleration of chemical reactions by dissolving substances in water;
Ensuring the movement of substances: the entry of most substances into the cell and their removal from the cell in the form of solutions;
Ensuring the dissolution of many chemicals (a number of salts, sugars);
Participation in a number of chemical reactions;
Participation in the process of thermoregulation due to the ability to slowly heat up and slowly cool down.
Make a diagram of the food chains of a terrestrial ecosystem, the components of which are: plants, hawks, grasshoppers, lizards. Indicate which component of this circuit is most often found in other power circuits.
Plants – grasshoppers – lizards – hawk.
The most common plants are producers in this chain.
Ticket 5
1. No. 1. Proteins, their role in the body
Composition of protein molecules. Proteins are organic substances whose molecules include carbon, hydrogen, oxygen and nitrogen, and sometimes sulfur and other chemical elements.
2. The structure of proteins. Proteins are macromolecules consisting of tens or hundreds of amino acids. A variety of amino acids (about 20 types) that make up proteins.
3. Species specificity of proteins - the difference in proteins that make up organisms belonging to different types, determined by the number of amino acids, their diversity, and the sequence of compounds in protein molecules. The specificity of proteins in different organisms of the same species is the reason for the rejection of organs and tissues (tissue incompatibility) when they are transplanted from one person to another.
4. The structure of proteins is a complex configuration of protein molecules in space, supported by a variety of chemical bonds - ionic, hydrogen, covalent. Natural co-
standing squirrel. Denaturation is a violation of the structure of protein molecules under the influence of various factors - heating, irradiation, and the action of chemicals. Examples of denaturation: a change in the properties of protein when boiling eggs, the transition of protein from a liquid to a solid state when a spider builds a web.
5. The role of proteins in the body:
Catalytic. Proteins are catalysts that increase the rate of chemical reactions in the cells of the body. Enzymes are biological catalysts;
Structural. Proteins are elements of the plasma membrane, as well as cartilage, bones, feathers, nails, hair, all tissues and organs;
Energy. The ability of protein molecules to oxidize, releasing the energy necessary for the body’s functioning;
Contractile. Actin and myosin are proteins that make up muscle fibers and ensuring their reduction due to the ability of the molecules of these proteins to denature;
Motor. Movement of a number of unicellular organisms, as well as spermatozoa, with the help of cilia and flagella, which contain proteins;
Transport. For example, hemoglobin is a protein that is part of red blood cells and ensures the transport of oxygen and carbon dioxide;
Storage. Accumulation of proteins in the body as reserve nutrients, for example in eggs, milk, plant seeds;
Protective. Antibodies, fibrinogen, thrombin - proteins involved in the development of immunity and blood clotting;
Regulatory. Hormones are substances that, along with nervous system humoral regulation of body functions. The role of the hormone insulin in the regulation of blood sugar.
No. 2. Biological significance of reproduction of organisms. Reproduction methods
1. Reproduction and its meaning. Reproduction is the reproduction of similar organisms, which ensures the existence of species for many millennia, contributes to an increase in the number of individuals of the species, and the continuity of life. Asexual, sexual and vegetative propagation organisms.
2. Asexual reproduction is the most ancient method. Asexuality involves one organism, while sexualization most often involves two individuals. In plants asexual reproduction with the help of a spore - one specialized cell. Reproduction by spores of algae, mosses, horsetails, mosses, ferns. The precipitation of spores from plants, their germination and the development of new daughter organisms from them into favorable conditions. Death of a huge number of spores exposed to unfavorable conditions. There is a low probability of the emergence of new organisms from spores, since they contain few nutrients and the seedling absorbs them mainly from the environment.
3. Vegetative propagation - propagation of plants using vegetative organs: above-ground or underground shoots, parts of roots, leaves, tubers, bulbs. Participation in vegetative propagation of one organism or its part. The similarity of the daughter plant with the mother plant, since it continues the development of the mother’s organism. Greater efficiency and distribution of vegetative propagation in nature, since the daughter organism is formed faster from a part of the mother organism than from a spore. Examples of vegetative propagation: using rhizomes - lily of the valley, mint, wheatgrass, etc.; rooting of the lower branches touching the soil (layering) - currants, wild grapes; mustache - strawberry; bulbs - tulip, daffodil, crocus. The use of vegetative propagation in the cultivation of cultivated plants: potatoes are propagated by tubers, onions and garlic by bulbs, currants and gooseberries by layering, cherries and plums by root suckers, and fruit trees by cuttings.
4. Sexual reproduction. The essence of sexual reproduction is the formation of germ cells (gamet), the fusion of a male germ cell (sperm) and a female one (ovum) - fertilization and the development of a new daughter organism from a fertilized egg. Thanks to fertilization, the production of a daughter organism with a more diverse set of chromosomes, which means with more diverse hereditary characteristics, as a result of which it may be more adapted to its environment. The presence of sexual reproduction in algae, mosses, ferns, gymnosperms and angiosperms. Complication of the sexual process in plants in the process of their evolution, the appearance of the most complex form in seed plants.
5. Seed propagation occurs with the help of seeds; it is characteristic of gymnosperms and angiosperms (vegetative propagation is also widespread in angiosperms). The sequence of stages of seed reproduction: pollination - the transfer of pollen on the stigma of the pistil, its germination, the appearance by division of two sperm, their advancement into the ovule, then the fusion of one sperm with the egg, and the other with the secondary nucleus (in angiosperms). The formation of a seed from the ovule - an embryo with a supply of nutrients, and from the walls of the ovary - a fruit. A seed is the rudiment of a new plant; in favorable conditions it germinates and at first the seedling feeds on the nutrients of the seed, and then its roots begin to absorb water and minerals from the soil, and the leaves begin to absorb carbon dioxide from the air. sunlight. Independent life of a new plant.
№3.
Prepare two microscopes for work, place microspecimens of the specified tissues on the stage, illuminate the field of view of the microscopes, and move the tube with screws to achieve a clear image. Examine micropreparations, compare them and indicate the following differences: cells of epithelial tissue are located tightly, adjacent to each other, and in connective tissue they are loose. There is little intercellular substance in epithelial tissue, but a lot in connective tissue.
Examine microscopic specimens of epithelial and connective tissue under a microscope and identify their differences.
Examine two microscopic samples using two microscopes. Epithelial tissue cells are located tightly, adjacent to each other, and connective tissue is loose. There is little intercellular substance in epithelial tissue, but a lot in connective tissue.
Ticket number 6
No. 1. Carbohydrates and fats, their role in the body.
1. Organic substances of the cell: carbohydrates, fats, proteins, nucleic acids, ATP. Macromolecules are large and complex molecules of organic compounds, consisting of simpler molecules - “building blocks”.
2. Carbohydrates are organic compounds consisting of carbon, hydrogen and oxygen.
3. Structure of carbohydrates. Simple carbohydrates - glucose, fructose. The presence of glucose in fruits, vegetables, human blood, fructose in fruits and honey. Complex carbohydrates are macromolecules consisting of remnants of simple carbohydrate molecules. Examples of complex carbohydrates: cellulose (fiber), starch, glycogen - animal starch produced in the liver. Formation of cellulose, starch and glycogen molecules from the residues of glucose molecules. The presence in one starch molecule is from several hundred to several thousand residues of glucose molecules, and in the composition of a cellulose molecule - over 10,000 units. Strength and insolubility of complex carbohydrate molecules.
4. The role of carbohydrates in the body:
Storage - the ability of complex carbohydrates to accumulate, forming a supply of nutrients. Examples: accumulation of starch in the cells of potato tubers and rhizomes of many plants; formation from glucose molecules and accumulation of glycogen in liver cells;
Energy - the ability of carbohydrate molecules to oxidize to carbon dioxide and water with the release of 17.6 kJ of energy during the oxidation of 1 g of carbohydrates;
Structural. Carbohydrates are an integral part of various parts and organelles of the cell. Example: the presence of a cell membrane consisting of cellulose and playing the role of an exoskeleton in plants.
5. Fats are organic substances. Hydrophobicity (insolubility in water) is the main property of fats.
Energy - the ability to oxidize to carbon dioxide and water with the release of energy (38.9 kJ of energy during the oxidation of 1 g of fat);
Structural. Fats are part of the plasma membrane;
Storage - the ability of fats to accumulate in the subcutaneous fatty tissue of animals, in the seeds of some plants (sunflower, corn, etc.);
Thermoregulatory: protection of the body from cooling in a number of animals - seals, walruses, whales, bears, etc.;
Protective: in a number of animals, protection of the body from mechanical damage, protection from wetting of feathers or hair with water
No. 2. Immunity. Fighting infectious diseases diseases. Prevention of HIV infection and AIDS.
1. Skin, mucous membranes, and the fluids they secrete (saliva, tears, gastric juice, etc.) are the first barrier in protecting the body from microbes. Their functions: serve as a mechanical barrier, a protective barrier that prevents microbes from entering the body; produce substances with antimicrobial properties.
2. The role of phagocytes in protecting the body from microbes. Penetration of phagocytes - a special group of leukocytes - through the walls of capillaries to places where microbes, poisons, and foreign proteins enter the body, enveloping and digesting them.
3. Immunity. The production of antibodies by leukocytes, which are carried by blood throughout the body, combine with bacteria and make them defenseless against phagocytes. Contact of certain types of leukocytes with pathogenic bacteria, viruses, release of substances by leukocytes that cause their death. The presence of these protective substances in the blood provides immunity - the body's immunity to infectious diseases. The effect of different antibodies on microbes.
4. Prevention of infectious diseases. Introduction into the human body (usually in childhood) of weakened or killed pathogens of the most common infectious diseases - measles, whooping cough, diphtheria, polio, etc. - to prevent the disease. A person’s immunity to these diseases or the course of the disease in a mild form due to the production of antibodies in the body. When a person is infected with an infectious disease, administering blood serum obtained from recovered people or animals. The content of antibodies in serum against a particular disease. 5. Prevention of HIV infection and AIDS. AIDS is an infectious disease characterized by a deficiency of immunity. HIV is a human immunodeficiency virus that causes loss of immunity, which makes a person defenseless against an infectious disease. Infection occurs through sexual contact, as well as through blood transfusions containing HIV, the use of poorly sterilized syringes, and during childbirth (infection of a child from a mother who is a carrier of the AIDS pathogen). Due to the lack effective treatment It is important to prevent infection with the AIDS virus: strict control of donor blood and blood products, the use of disposable syringes, the exclusion of promiscuity, the use of condoms, and early diagnosis of the disease.
No. 3. Make pi diagrams the chains of the aquarium in which live: crucian carp, snails (pond snail and coil), plants (elodea and vallisneria), slipper ciliates, saprophytic bacteria. Explain what will happen in an aquarium if shellfish are removed from it.
An aquarium is a model of an ecosystem, a limited water space. Three groups of organisms living in the aquarium: producers of organic substances (algae and higher aquatic plants); consumers of organic substances (fish, unicellular animals, mollusks); destroyers of organic substances (bacteria, fungi that decompose organic residues into mineral substances).
Aquarium food chains:
saprophytic bacteria -- "slipper ciliates --" crucian carp;
saprophytic bacteria --» mollusks;
plants --" fish;
organic remains - shellfish.
Mollusks clean the walls of the aquarium and the surface of plants from various organic residues. The exclusion of shellfish from the food chain leads to turbidity in the water as a result of the massive proliferation of bacteria, as well as the release of metabolic products and undigested food debris by fish.
Ticket No. 7
No. 1. The nucleus, its structure and role in the transmission of hereditary information.
1. The nucleus is the main part of the cell. The presence of a nucleus in eukaryotic cells. Mononucleate and multinucleate cells.
2. Eukaryotes are organisms that have a nucleus in their cells, delimited from the cytoplasm by a nuclear membrane (fungi, plants, animals).
3. Structure of the nucleus: nuclear envelope, consisting of two membranes and having pores; nuclear juice; nucleoli; chromosomes. The role of the nuclear membrane in separating the contents of the nucleus from the cytoplasm. Connection between the internal contents of the nucleus and the cytoplasm through pores. Nucleoli are “workshops” for assembling ribosomes.
4. Chromosomes are structures located in the nucleus and consisting of one DNA molecule and protein molecules connected to it.
5. Set of chromosomes in cells. Somatic cells are all cells of a multicellular organism, except the sex cells. Diploid (double) set of chromosomes in somatic cells of most organisms (2p). Haploid (single) set of chromosomes in germ cells (In). The set of chromosomes in human somatic (2n = 46) and germ (In = 23) cells. Homologous - chromosomes that have the same shape, size and determine the manifestation of the same characteristics (the color of flowers, or the shape of fruits, or the growth of the organism, etc.). Non-homologous - chromosomes belonging to different pairs that differ in shape, size, and are responsible for the manifestation of different characteristics (for example, the color and shape of seeds in peas). The number, size and shape of chromosomes are the main characteristics of the species. Changes in the number, shape or size of chromosomes are the cause of mutations.
6. Chromosome structure. Chromatids are two identical thread-like structures consisting of a DNA molecule and associated protein molecules, forming one chromosome and interconnected in the region of the primary constriction - the centromere.
7. Genes - units of heredity - sections of chromosomes that determine the manifestation of certain characteristics in an organism, for example, height, body weight, fur color in animals or flower colors in plants, etc. Gene - a section of a DNA molecule containing information about one protein chain. The content of a large number (up to several thousand) genes in one DNA molecule.
8. The role of the nucleus: participation in cell division, storage and transmission of hereditary characteristics of the body, regulation of vital processes in the cell.
71. Let's find out why transport of substances is needed for multicellular organisms.
Thanks to the transport of substances, all minerals and various proteins, carbohydrates, fats reach their “destination” and begin to rapidly synthesize with other molecules.
72. Let's draw a plant and label its organs.
73. Let's write what substances move:
a) through wood vessels: minerals
b) along the sieve tubes of the bast: organic substances.
74.
Connective tissue. Thanks to the proteins contained in the blood, it performs many functions, including transport and protective.
75.
Let's define the concept of blood and its functions in the body.
In a closed c.s. the blood moves in a circle, and in an open circle, the blood vessels open into the body cavity.
76. Let's label the sections of the circulatory system shown in the pictures. Let's determine their type.
77. Let's supplement the sentences.
78. Let's give definitions.
An artery is a vessel through which oxygenated blood moves to the organs.
A vein is a vessel through which blood saturated with carbon dioxide moves from the organs.
A capillary is the smallest vessel that penetrates the entire body of an animal.
79. Let's label the parts of the heart indicated by numbers in the pictures. Let's write down the animals to which the hearts shown belong.
Laboratory work.
"Movement of water and minerals along the stem."
1. Transport through the lipid bilayer of the membrane (simple diffusion) and transport with the participation of membrane proteins
2. Active and passive transport
3. Simport, antiport and uniport
The easiest molecules to pass through the lipid bilayer are nonpolar molecules with small molecular weight(eg oxygen, nitrogen, benzene). Small polar molecules such as carbon dioxide, nitric oxide, water, and urea penetrate quite quickly through the lipid bilayer. Ethanol and glycerol, as well as steroid and thyroid hormones, pass through the lipid bilayer at a noticeable rate. For larger polar molecules (glucose, amino acids), as well as for ions, the lipid bilayer is practically impermeable, since its interior is hydrophobic.
The transfer of large polar molecules and ions occurs due to channel proteins or carrier proteins. Thus, in cell membranes there are channels for sodium, potassium and chlorine ions, as well as transport proteins for glucose, amino acids and other molecules. There are even special water channels - aquaporins.
Passive transport- transport of substances along a concentration gradient, which does not require energy consumption. Passive transport of hydrophobic substances occurs through the lipid bilayer of the membrane (∆G<0). Пассивно пропускают через себя вещества все белки-каналы и некоторые белки-переносчики. Пассивный транспорт с участием мембранных белков называют facilitated diffusion. Other carrier proteins (sometimes called “pump” proteins) transport substances across the membrane using energy, which is released during the hydrolysis of ATP. This type of transport is carried out against a concentration gradient transported substance and is called active transport.
Membrane transport of substances also differs in the direction of their movement and the amount of substances carried by a given carrier protein:
1) Uniport- transport of one substance in one direction depending on the concentration gradient.
2) Simport- transport of two substances in one direction using one carrier.
3) Antiport- movement of two substances in different directions through one carrier.
The main mechanisms for the movement of substances through the membrane are depicted in the following diagram:Uniport carries out a voltage-gated sodium channel through which sodium cations move into the cell during the generation of an action potential.
Simport carries out a glucose transporter located on the external (facing the intestinal lumen) side of the intestinal epithelial cells. This protein simultaneously captures a glucose molecule and a sodium cation and, changing its conformation, transfers both substances into the cell. This uses the energy of the electrochemical gradient, which, in turn, is created due to the hydrolysis of ATP by the enzyme sodium-potassium ATPase.
Antiport carried out by sodium-potassium ATPase. It transports 2 potassium cations into the cell and removes 3 sodium cations from the cell.
The operation of sodium-potassium ATPase is an example of active transport by antiport.
Mechanisms of transport of large fragments (biomolecules)
Endocytosis - capture of a large fragment by a cell. First, the membrane surrounds this fragment, forming a vesicle - the primary phagosome, then this vesicle merges with the cell organelle - the lysosome, where the fragment of the substance is broken down by the enzymes of the lysosome.
Fluid entrapment is called pinocytosis, solid matter capture - phagocytosis.
The process of releasing large fragments from a cell is called exocytosis, it occurs through the Golgi apparatus.
Example an antitumor drug that blocks transport across membranes.
Human estrogen-positive breast cancer cells transplanted into the body of a laboratory mouse died under the influence of a drug that blocks the transport of nutrients. This is the only transport that can supply all the essential amino acids necessary for the cell to survive, incl. tumor. Another type of cancer cell (estrogen-negative) is not affected by the drug. The drug is developed on the basis of the amino acid - alpha-methyl-(D,L)-tryptophan. The substance is capable of depriving nutrition only of cells that use this type of transport. The discovery will make it possible to defeat breast cancer, which cannot be treated with traditional drugs such as tamoxifen* or Clomid*.
*Clomid (clomiphene) and tamoxifen (Nolvadex) are antiestrogens belonging to the same group of chemicals - triphenylethylenes.
LECTURE No. 4
Buffer solutions. Buffer systems of the human body
Inorganic buffer systems.
Hasselbach-Genderson equation for type I and type II buffers.
Organic buffer systems.
Buffer systems of the human body.
Purpose: to study the general properties of buffer systems, to familiarize with the body’s buffer systems and their functioning.
Literature:Berezov T. T., Korovkin B. F. Biological chemistry: Textbook under. ed. acad. USSR Academy of Medical Sciences S.S. Debova. - 2nd ed., revised. and additional - M.: Medicine, 1990. 528 p.
Relevance. Buffer systems are widely represented in living organisms, incl. in humans. Buffers are used for laboratory research and also as a medium for storing tissue cells. Buffer solutions with a properly selected composition are used to correct the electrolyte composition and blood pH in patients ( acidosis, alkalosis). For these purposes, buffer solutions are specially prepared, having previously calculated their composition so that the electrolyte composition and pH of the system correspond to the purposes of use.
Buffer(buffer, buff- soften the blow) are called solutions with a stable concentration of H + ions, i.e. The pH of which does not change with dilution and the addition of small amounts of a strong acid or strong base. Any buffer contains at least 2 substances, one of which is capable of binding H + protons, and the second binds hydroxyl groups OH - in poorly dissociable compounds .