What is the meaning of sexual reproduction. Sexual reproduction. Reproduction and evolution
REMEMBER
Question 1. What is the meaning of reproduction?
During reproduction, hereditary information is transferred from parental forms to offspring, which ensures the reproduction of traits not only of a given species, but also of specific parental individuals. Consequently, reproduction maintains the long existence of the species, while maintaining the continuity between parents and their offspring in a series of many generations.
Question 2. What functions does the cell nucleus perform?
The nucleus stores hereditary information and passes it on to daughter cells during division. On DNA molecules, in the process of transcription (rewriting of information), mRNA molecules are synthesized that transfer information about the structure of proteins from the nucleus to the sites of their synthesis in the extranuclear cytoplasm. In the nucleus, as a result of mutations, hereditary information can change, which leads to hereditary variability.
In the nuclei with the participation of the nucleoli, ribosomes are formed, which then enter the cytoplasm and participate in the biosynthesis of proteins. Thus, due to the implementation of hereditary information encoded as a sequence
Question 1. How does sexual reproduction occur in flowering plants?
In flowering plants, germ cells are formed in the flower: male - in the stamens, and female - in the pistils (Fig. 85). Pollen grains (pollen) ripen inside the anther of the stamen. At the tip of the pestle there is a sticky stigma that traps pollen.
The pistil contains an ovary containing one or more ovules. In the pollen grains, the male germ cells mature, and inside the ovule, the female germ cell.
In order for a fruit to start in a flower and seeds to form, pollination must occur, that is, pollen must fall on the stigma of the pistil. After the pollen grain has landed on the stigma of the pistil, it germinates, forming a pollen tube, which reaches the ovule through the style of the pistil. Male germ cells penetrate the ovule through the pollen tube, and fertilization occurs - the fusion of two germ cells - male and female. As a result of fertilization, one cell is formed, it is called a zygote. Then the zygote divides into two cells, then into four, eight, etc. A multicellular seed embryo develops. In addition to the embryo, a mature seed contains a storage tissue (endosperm) and a seed coat.
Question 2. What is the biological significance of sexual reproduction of organisms?
During sexual reproduction, parents pass on their genes to their offspring, therefore, the offspring will not be an exact copy of the parent. He will have new properties that will help him survive in the environment. And with asexual reproduction, the offspring are copies of the parent. No variety of signs, properties, it is harder for him to survive.
Question 3. How does asexual reproduction differ from sexual reproduction?
Unlike asexual reproduction, two individuals participate in sexual reproduction, forming special sex cells - gametes. Distinguish between male and female gametes, which are formed in male and female organisms, respectively. The formation of germ cells occurs in special organs, which are called the reproductive organs or organs of sexual reproduction. Gametes carry chromosomes that contain information about hereditary traits.
THINK!
Why is the offspring different in sexual reproduction?
Simple heredity is observed during vegetative reproduction, i.e., when a new individual is formed from the vegetative part of an already existing individual, spores. It is widespread in plants, bacteria, protozoa, sponges, coelenterates, and some other animals prone to asexual reproduction. Simple heredity is manifested during reproduction, both by specialized cells (spores) and by peculiar organs of vegetative reproduction (tubers, bulbs, brood buds, etc.). The category of complex heredity extends to all cases where development begins from the egg, including here parthenogenesis. During vegetative reproduction, the properties of one individual are transmitted to offspring, while during the sexual process, the zygote, from which a new individual will develop, carries hereditary information from two organisms. It is quite obvious that in the latter case, the patterns of inheritance of parental properties are more complex and more diverse.
Read the text of the textbook. What damage to human health is caused by bad habits? Find more information online.
Bad habits of a person are a repeatedly repeated series of actions, reaching the level of automatism. These actions are harmful in terms of social welfare, the people around them, or the condition of the person trapped in this habit.
The most striking characteristics of bad habits are the inexpediency, harmfulness and automaticity of actions that a person performs as a result of weak will.
The impact of bad habits on human health is quite detrimental. Of course, not everyone. There are good habits (brush your teeth, wash your face every morning, say hello to everyone, exercise, etc.).
The “harmfulness” of bad habits lies in the fact that in the end they will certainly subdue all the activities of the “ill” one. After all, bad habits are characterized by addiction, which is difficult to get rid of.
Alcohol;
drugs;
toxic substances;
Laziness and passivity;
The habit of biting a pen, nails, licking fingers;
The habit of eating in front of the TV;
Constant delays;
Love for sweets;
Shifting all important matters to the last moment or “tomorrow”;
The habit of leaving behind a mess;
Wrong nutrition;
Non-compliance with the daily routine.
As you can see, the list is impressive. Do you think that many of the list cannot be called bad habits? Then imagine the situation: you went with a girl to a restaurant, had a delicious dinner with oysters, and then the companion began to lick her fingers. Nicely? And if she does it always and everywhere - after ice cream in the park, after scrambled eggs for breakfast, after popcorn at the cinema?
But the most terrible consequences, of course, are the habits of using alcohol, nicotine, drugs, because they can develop into addiction. So, what can these "pests" lead to?
The dangers of smoking for human health are as follows:
Calcium is “drawn out” from the body, teeth deteriorate and turn yellow, the structure of nails and hair is destroyed, the skin of the face turns gray;
Vessels lose their elasticity and become weak and fragile, oxygen supply to the brain and all cells deteriorates, symptoms of hypertension appear;
Functioning deteriorates digestive system, an ulcer is formed;
The risk of heart disease, broncho-pulmonary tract, cancer, etc. increases.
Alcohol can lead to the following problems:
The body's resistance to various diseases weakens;
The work of the liver worsens and it gradually collapses;
The level of sugar in the blood rises;
The work of the digestive and nervous systems worsens;
Mortality is increasing as a result of poisoning with fusel oils, suicide, and accidents;
Gradually memory is lost, the person degrades.
Drug addiction is the worst enemy modern society. Its influence can be described for a long time, but let's note the most serious threats:
Life is significantly shortened;
Mortality is increasing as a result of drug poisoning, suicide, accident;
Somatic and neuralgic complications appear;
The personality is grossly degraded;
The body ages quickly;
Criminogenic behavior is manifested;
The risk of contracting incurable diseases, such as HIV, increases.
As mentioned above, bad habits are difficult to treat and correct. Therefore, so that they do not appear, it is necessary to think about preventive measures.
Of course, it is more difficult for an adult to convince, teach and change his behavior, but the mind of a teenager responds well to the correct presentation of information about the dangers of using drugs, alcohol, smoking and other habits.
Showing films, videos, visual aids (for example, the lungs of a smoker, the liver of an alcoholic or ulcers on the body of a drug addict), thematic conversations with the participation of doctors, psychologists, lawyers and other specialists are effective means.
Reproduction is the reproduction by an organism of its own kind. Thanks to him, the continuity of life is ensured. There are two ways of forming new organisms: asexual and sexual reproduction. Asexual, in which only one organism takes part, is carried out with the help of cell division in half, sporulation, budding, or vegetatively. It is characteristic mainly of primitive organisms. In asexual reproduction, new organisms are a copy of the parent. Sexual reproduction occurs with the help of sex cells called gametes. Two organisms mainly take part in it, which contributes to the emergence of new individuals that differ from the parent ones. Many animals alternate between asexual and sexual reproduction.
Types of sexual reproduction
There are such types of sexual reproduction:
- bisexual;
- hermaphroditic;
- parthenogenesis, or virgin reproduction.
Dioecious reproduction
Dioecious reproduction is characterized by the fusion of haploid gametes, which is called fertilization. During fertilization, a diploid zygote is formed containing the genetic information of both parents. Dioecious reproduction is characterized by the presence of a sexual process.
Types of the sexual process
There are three types of sexual process:
- Isogamy. It is characterized by the fact that all gametes are mobile and have the same size.
- Anisogamy or heterogamy. Gametes have various sizes, there are macrogametes and microgametes. But both gametes are capable of movement.
- Oogamy. It is characterized by the presence of a large immobile egg and a small sperm cell capable of movement.
Hermaphroditism
Parthenogenesis
Some organisms are able to develop from an unfertilized cell. This sexual reproduction is called parthenogenesis. Ants, bees, wasps, aphids and some plants breed with it. A variation of parthenogenesis is pedogenesis. It is characterized by virgin reproduction of larvae. Some Diptera and beetles reproduce by pedogenesis. Parthenogenesis provides a rapid increase in population size.
Plant propagation
Plants, like animals, can reproduce asexually and sexually. The difference is that the sexual reproduction of angiosperms occurs through double fertilization. What is it? With double fertilization, discovered by Navashin S.G., two sperm are involved in the fertilization of the egg. One of them unites with the egg. This produces a diploid zygote. The second sperm fuses with the diploid central cell, forming a triploid endosperm containing a supply of nutrients.
The biological meaning of sexual reproduction
Sexual reproduction makes organisms resistant to changing and adverse conditions. environment increases their viability. This is facilitated by the diversity of offspring born as a result of the combination of the heredity of two organisms.
1. What words in the sentences are omitted and replaced by letters (a-c)?
"Reproduction by living organisms of their own kind is called (a). There are two types of reproduction: (b) and (c)."
The following words are replaced by letters: a - reproduction (self-reproduction), b, c - asexual and sexual.
2. What is the biological significance of the reproduction of organisms?
Reproduction is an integral property of all living organisms, providing an increase in the number of individuals of a particular species. During reproduction, hereditary information is transferred from parental forms to offspring, which ensures the reproduction of traits not only of a given species, but also of specific parental individuals. Thus, reproduction ensures the long-term existence of biological species, while maintaining continuity between parents and their descendants over many generations.
3. In what ways can asexual reproduction be carried out in bacteria, protists, fungi, plants and animals? What forms of asexual reproduction are based on the phenomenon of regeneration?
Bacteria reproduce by cell division (more precisely, by simple binary fission). Unicellular protists can reproduce by cell division (for example, amoeba, euglena, ciliates) or with the help of spores (for example, chlorella). The main methods of asexual reproduction of multicellular algae and fungi are fragmentation of the thallus (or mycelium) and reproduction using spores. Asexual reproduction of plants is carried out using spores, as well as vegetatively. In primitive animals (sponges, coelenterates, some worms), budding and fragmentation are observed.
Vegetative reproduction and reproduction by fragmentation are based on the phenomenon of regeneration.
4. What methods of vegetative propagation are widely used in agriculture? Why? Give examples.
In agriculture, the propagation of cultivated plants by stem (currant, grapes) and leaf (Uzambara violet, begonia) cuttings, layering (gooseberry), modified shoots - tubers (potato, Jerusalem artichoke), bulbs (onion, garlic, tulip, narcissus), mustache (strawberries), etc. These methods of reproduction allow you to get a large number of daughter plants in a relatively short period of time.
In horticulture, vegetative propagation by grafting is common. This method allows you to quickly propagate valuable plants and ensures their accelerated development with full preservation of varietal qualities. The grafted cultivated plant (graft) can obtain such valuable properties of the rootstock (the plant that is grafted on) as frost resistance, disease resistance, undemanding soil fertility, etc.
5. What are the features of asexual reproduction of plants and animals?
In the development cycle of all plants, there is a strict alternation of two generations - gametophyte and sporophyte and, accordingly, two methods of reproduction - sexual and asexual. At the same time, special organs (sporangia) are formed in the sporophyte, in which specialized cells, spores, are formed by meiosis. They consist of a nucleus and cytoplasm with minimal nutrients. Under favorable conditions, spores germinate and give rise to new organisms.
In addition, many plants are capable of vegetative propagation. In this case, daughter individuals develop from the vegetative organs (or parts thereof) of the mother plant.
Among animals, asexual reproduction is observed only in primitive forms - sponges, coelenterates, and some worms. Asexual reproduction of these animals is carried out by budding or fragmentation.
6. When propagating plants with lignified cuttings, it is recommended to make an incision in the lower part of the cutting for faster rooting. What layer of tissue do you think you need to go deep? What kind of roots are formed on the cuttings?
The incision must be made before the cambium. Injury to the cells of the educational tissue causes stimulation of division, which helps to accelerate the process of root formation. The roots that form on the cuttings are called adventitious.
7*. In horsetails, the outer shell of each spore forms two ribbons, which unwind in dry air and unite the spores with each other. Due to this, horsetail spores spread in groups. In other plants, such as the fern, the spores scatter one by one. What is the reason for the presence of ribbons in horsetail spores and why do spores of the thyroid gland not have such adaptations?
Outgrowths (gametophytes) develop from spores of horsetails and ferns. In the thyroid gland, the outgrowths are bisexual, and in horsetails they are dioecious (antheridia are formed on some outgrowths, and archegonia on others). Due to the presence of ribbons, horsetail spores spread in groups, so male and female gametophytes are in close proximity to each other, which contributes to fertilization.
* Tasks marked with an asterisk require students to put forward various hypotheses. Therefore, when setting a mark, the teacher should focus not only on the answer given here, but take into account each hypothesis, evaluating the biological thinking of students, the logic of their reasoning, the originality of ideas, etc. After that, it is advisable to familiarize students with the answer given.
Natural selection. He decides which adaptations for a given habitat are favorable and which are not so desirable. If the adaptation is favorable, then organisms that have coding for that trait will live long enough to reproduce and pass on their genes to the next generation.
In order for natural selection to work for a population, there must be diversity. To get diversity in individuals, you need different genetics and expressed. It all depends on the method of reproduction of a particular species.
asexual reproduction
Asexual reproduction is the production of offspring from one parent that is not accompanied by mating or mixing of genes. Asexual reproduction results in cloning of the parent, meaning the offspring have identical DNA to their ancestor. As a rule, there is no species diversity from generation to generation.
One way to get some species diversity is through mutations at the DNA level. If an error occurs in the process or copying of the DNA, then this error will be passed on to the offspring, possibly changing its traits. However, some mutations do not change the phenotype, so not all changes in asexual reproduction result in offspring variations.
sexual reproduction
Sexual reproduction occurs when a female sex cell (egg) combines with a male cell (sperm). A descendant is a genetic combination of mother and father, half of its chromosomes come from one parent and the other half from the other. This ensures that the offspring are genetically different from their parents and even siblings.
Mutations can also occur in sexually reproducing species to further increase the diversity of offspring. The process that creates the (sex cells) used for reproduction also contributes to increased diversity. It ensures that the resulting gametes are genetically different. Independent recruitment during meiosis and random fertilization also affects gene mixing and allows offspring to better adapt to their environment.
Reproduction and evolution
As a rule, it is believed that sexual reproduction is more conducive to evolution than asexual reproduction, since it has much more. The evolution of an asexual population is usually facilitated by a sudden mutation.
Sexual reproduction - section Education, Essence of life Has a Universal Character, I.e. It is peculiar to Practical...
Has a universal character, i.e. it is characteristic of almost all living organisms (it is possible that in organisms that do not reproduce sexually, this process is simply unknown to researchers, although it really exists)
It is assumed that in the process of evolution, sexual reproduction, which has existed for more than 3 billion years, was preceded by asexual reproduction, which arose before sexual
The biological significance of sexual reproduction:
1. increase in the number of individuals (self-reproduction); individuals at the same time have recombined hereditary properties and traits of two parents and therefore are extremely diverse
2. ensuring biological diversity, hereditary variability of individuals of the same species, which provides material for natural selection, progressive evolution, adaptiogenesis)
Consists of four main processes:
1. gametogenesis - formation of sex cells (gametes)
2. fertilization (sexual process)) - the fusion of gametes and their nuclei and the formation of a zygote
3. embryogenesis (crushing of the zygote, formation and development of the embryo)
4. postembryogenesis (growth and development of the organism in the post-embryonic period)
sex cells (gametes) )
Gametes - these are germ cells specialized for performing the reproductive function, upon fusion of which a zygote is formed, from which a new individual develops(female sex cells are called male eggs - spermatozoa, spermatozoons, spermatozoa)
Gametes are highly differentiated cells characterized by the following features:
1. have a haploid set of chromosomes in the nuclei, which ensures the restoration in the zygote of a diploid set of chromosomes typical for this species
2. low level of metabolic processes, close to the state of suspended animation
3. changed nuclear-plasma relations(ratio of the volume of the nucleus to the cytoplasm)
4. not capable of mitotic division
In most organisms, germ cells are divided into maternal (eggs) and paternal (spermatozoa), which differ in a number of structural and functional features ( sexual dimorphism)
| Oocytes | Spermatozoa (sperm) |
| 1. Motionless, does not have special organs of active movement (in humans, it overcomes the distance to the uterine cavity, equal to 10 cm, in 4–7 days) 2. They are large in size (a large volume of cytoplasm); in mammals it has a size of about 100 - 200 microns, the largest egg in the herring shark is more than 29 cm. implantation) the embryo in the wall of the uterus in placental animals 5. Form and accumulate in the cytoplasm the yolk and pigments in the form of granules (supply of nutrients) 6. Have many mitochondria and plastids (in plants) 7. Have no acrosome 8. Characteristic cytoplasmic segregation - after fertilization in a not yet crushed egg, a regular redistribution of the cytoplasm occurs, which determines the direction of development of the tissues of the embryo 9. They have polarity, due to the occurrence animal and vegetative poles 10. They have a spherical or slightly elongated shape 11. They do not carry a charge 12. They are formed in insignificant quantities compared to spermatozoa 13. They are surrounded by an acidic fluid 14. They are formed in animals in the ovaries (in plants in archegonia) 15. They have reduced nuclear-plasma ratios, because they have a large volume of cytoplasm 16. The ability to enter the mitotic cycle is restored during fertilization 17. Absent 18. Protoplasm has a colloidal state 19. Little resistant to adverse environmental factors | 1. They are mobile, have an apparatus of active movement in the form of a flagellum (in a person it develops a speed of up to 5 cm / h); plant sperm, even without a flagellum, are also mobile 2. Very small, very small amount of cytoplasm (in humans - 50-70 microns, crocodile - 20 microns); the main task is to transport the DNA of an individual to the egg 3. The metabolism is very active 4. They do not have additional membranes 5. They do not form yolk and pigments, they do not have a supply of nutrients 6. Plant spermatozoa do not have plastids 7. They have an acrosomal apparatus (acrosome) - a modified Golgi apparatus containing enzymes for dissolving the egg cell membrane during fertilization 8. Cytoplasmic segregation does not occur 9. Non-polar 10. They have a head (acrosome and nucleus), a neck (centriole and a spiral thread formed from mitochondria) and a tail (axial thread of the flagellum 11 All spermatozoa carry the same negative charge, which prevents them from sticking together 12. In animals, a colossal number is formed (10 7 10 10 pieces are released during each sexual act in humans, 200 million are released) 13. In mammals, they are localized in the seminal fluid, which has an alkaline environment 14. Formed in animals in testicles (in plants in antheridia) 15. Have high nuclear-plasma ratios due to the small amount of cytoplasm 16. Do not enter the mitotic cycle 17. Have positive chemotaxis (actively move against the flow of fluid towards the egg) 18. Protoplasm of the head has a liquid-crystalline state 19. More resistant to adverse environmental conditions |
v In monoecious plants and hermaphroditic animals, eggs and sperm develop in the same organism
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Essence of life
Living matter qualitatively differs from non-living matter in its enormous complexity and high structural and functional orderliness. Living and non-living matter are similar at the elementary chemical level, i.e. Chemical compounds of cell matter..
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All topics in this section:
Mutation process and reserve of hereditary variability
In the gene pool of populations, a continuous mutation process occurs under the influence of mutagenic factors Recessive alleles mutate more often (encode less resistant to the action of mutagenic fa
Allele and genotype frequencies (population genetic structure)
The genetic structure of a population is the ratio of the frequencies of alleles (A and a) and genotypes (AA, Aa, aa) in the gene pool of the population Allele frequency
Cytoplasmic inheritance
There are data that are inexplicable from the point of view of the chromosome theory of heredity by A. Weisman and T. Morgan (i.e., exclusively nuclear localization of genes) The cytoplasm is involved in re
Plasmogenes of mitochondria
One myotochondria contains 4-5 circular DNA molecules about 15,000 base pairs long Contains genes for: - synthesis of t RNA, p RNA and ribosome proteins, some aero enzymes
Plasmids
Plasmids are very short, autonomously replicating circular fragments of the bacterial DNA molecule that provide non-chromosomal transmission of hereditary information.
Variability
Variability is a common property of all organisms to acquire structural and functional differences from their ancestors.
Mutational variability
Mutations - qualitative or quantitative DNA of body cells, leading to changes in their genetic apparatus (genotype) Mutation theory of creation
Causes of Mutations
Mutagenic factors (mutagens) - substances and influences capable of inducing a mutational effect (any factors of the external and internal environment that can
Mutation frequency
· The frequency of mutation of individual genes varies widely and depends on the state of the organism and the stage of ontogeny (usually increases with age). On average, each gene mutates once every 40,000 years.
Gene mutations (point, true)
The reason is a change in the chemical structure of the gene (violation of the nucleotide sequence in DNA: * gene inserts of a pair or several nucleotides
Chromosomal mutations (chromosomal rearrangements, aberrations)
Causes - are caused by significant changes in the structure of chromosomes (redistribution of the hereditary material of chromosomes) In all cases, they arise as a result of ra
polyploidy
Polyploidy - a multiple increase in the number of chromosomes in a cell (the haploid set of chromosomes -n is repeated not 2 times, but many times - up to 10 -1
The meaning of polyploidy
1. Polyploidy in plants is characterized by an increase in the size of cells, vegetative and generative organs - leaves, stems, flowers, fruits, root crops, etc. , y
Aneuploidy (heteroploidy)
Aneuploidy (heteroploidy) - a change in the number of individual chromosomes that is not a multiple of the haploid set (in this case, one or more chromosomes from a homologous pair are normal
Somatic mutations
Somatic mutations - mutations that occur in the somatic cells of the body Distinguish between gene, chromosomal and genomic somatic mutations
The law of homologous series in hereditary variability
· Discovered by N. I. Vavilov on the basis of the study of wild and cultivated flora of five continents 5. The mutation process in genetically related species and genera proceeds in parallel, in
Combination variability
Combinative variability - variability resulting from the regular recombination of alleles in the genotypes of offspring, due to sexual reproduction
Phenotypic variability (modification or non-hereditary)
Modification variability - evolutionarily fixed adaptive reactions of an organism to a change in the external environment without changing the genotype
The value of modification variability
1. most modifications have an adaptive value and contribute to the adaptation of the body to a change in the external environment 2. can cause negative changes - morphoses
Statistical patterns of modification variability
· Modifications of a single trait or property, measured quantitatively, form a continuous series (variation series); it cannot be built according to an unmeasurable feature or a feature that exists
Variation curve of the distribution of modifications in the variation series
V - trait variants P - frequency of occurrence of trait variants Mo - mode, or most
Differences in the manifestation of mutations and modifications
Mutational (genotypic) variability Modification (phenotypic) variability 1. Associated with changes in the geno- and karyotype
Features of a person as an object of genetic research
1. It is impossible to purposefully select parental pairs and experimental marriages (impossibility of experimental crossing) 2. Slow generational change, which occurs on average after
Methods for studying human genetics
Genealogical method The method is based on the compilation and analysis of pedigrees (introduced into science in late XIX in. F. Galton); the essence of the method is to trace us
twin method
The method consists in studying the patterns of inheritance of traits in single and dizygotic twins (the frequency of birth of twins is one case per 84 newborns)
Cytogenetic method
Consists of a visual study of mitotic metaphase chromosomes under a microscope Based on the method of differential staining of chromosomes (T. Kasperson,
Dermatoglyphics method
Based on the study of the relief of the skin on the fingers, palms and plantar surfaces of the feet (there are epidermal protrusions - ridges that form complex patterns), this trait is inherited
Population-statistical method
Based on statistical (mathematical) processing of inheritance data in large groups population (populations - groups that differ in nationality, religion, race, profession
Somatic cell hybridization method
Based on the reproduction of somatic cells of organs and tissues outside the body in sterile nutrient media (cells are most often obtained from the skin, bone marrow, blood, embryos, tumors) and
Modeling method
· Theoretical basis biological modeling in genetics gives the law of homological series of hereditary variability N.I. Vavilova For modeling, certain
Genetics and medicine (medical genetics)
Studying the causes, diagnostic signs, possibilities of rehabilitation and prevention of human hereditary diseases (monitoring of genetic abnormalities)
Chromosomal diseases
The reason is a change in the number (genomic mutations) or structure of chromosomes (chromosomal mutations) of the karyotype of the germ cells of the parents (anomalies can occur at different
Polysomy on sex chromosomes
Trisomy - X (Triplo X syndrome); Karyotype (47, XXX) Known in women; syndrome frequency 1: 700 (0.1%) N
Hereditary diseases of gene mutations
Cause - gene (point) mutations (changes in the nucleotide composition of a gene - insertions, substitutions, dropouts, transfers of one or more nucleotides; the exact number of genes in a person is unknown
Diseases controlled by genes located on the X or Y chromosome
Hemophilia - blood incoagulability Hypophosphatemia - loss of phosphorus and lack of calcium by the body, softening of the bones Muscular dystrophy - structural disorders
Genotypic level of prevention
1. Search and application of antimutagenic protective substances Antimutagens (protectors) are compounds that neutralize a mutagen before it reacts with a DNA molecule or remove it
Treatment of hereditary diseases
1. Symptomatic and pathogenetic - impact on the symptoms of the disease (the genetic defect is preserved and transmitted to offspring) n dieter
Gene Interaction
Heredity - a set of genetic mechanisms that ensure the preservation and transmission of the structural and functional organization of a species in a number of generations from ancestors
Interaction of allelic genes (one allelic pair)
There are five types of allelic interactions: 1. Complete dominance 2. Incomplete dominance 3. Overdominance 4. Codominance
complementarity
Complementarity - the phenomenon of the interaction of several non-allelic dominant genes, leading to the emergence of a new trait that is absent in both parents
Polymerism
Polymeria - the interaction of non-allelic genes, in which the development of one trait occurs only under the action of several non-allelic dominant genes (polygene
Pleiotropy (multiple gene action)
Pleiotropy - the phenomenon of the influence of one gene on the development of several traits The reason for the pleiotropic influence of a gene is in the action of the primary product of this
Selection basics
Selection (lat. selektio - selection) - science and industry of agricultural. production, developing the theory and methods of creating new and improving existing plant varieties, animal breeds
Domestication as the first stage of selection
Cultivated plants and domestic animals are descended from wild ancestors; this process is called domestication or domestication The driving force behind domestication is the suit
Centers of origin and diversity of cultivated plants (according to N. I. Vavilov)
Center name Geographical position Homeland of cultivated plants
Artificial selection (selection of parent pairs)
Two types of artificial selection are known: mass and individual
Hybridization (crossing)
Allows you to combine certain hereditary traits in one organism, as well as get rid of undesirable properties Use in breeding various systems crosses &n
Inbreeding (inbreeding)
Inbreeding is the crossing of individuals with a close degree of kinship: brother - sister, parents - offspring (in plants, the closest form of inbreeding occurs when self-breeding
Outbreeding (outbreeding)
When crossing unrelated individuals, harmful recessive mutations that are in the homozygous state become heterozygous and do not adversely affect the viability of the organism
heterosis
Heterosis (hybrid strength) is a phenomenon of a sharp increase in the viability and productivity of first-generation hybrids during unrelated crossing (interbreeding).
Induced (artificial) mutagenesis
The frequency with the spectrum of mutations increases dramatically when exposed to mutagens (ionizing radiation, chemicals, extreme environmental conditions, etc.)
Interline hybridization in plants
It consists in crossing pure (inbred) lines obtained as a result of long-term forced self-pollination of cross-pollinated plants in order to obtain maximum
Vegetative propagation of somatic mutations in plants
The method is based on the isolation and selection of useful somatic mutations for economic traits in the best old varieties (possible only in plant breeding)
Methods of breeding and genetic work by I. V. Michurina
1. Systematically distant hybridization
polyploidy
Polyploidy - the phenomenon of a multiple of the main number (n) of an increase in the number of chromosomes in the somatic cells of the body (the mechanism for the formation of polyploids and
Cell engineering
Cultivation of individual cells or tissues on artificial sterile nutrient media containing amino acids, hormones, mineral salts and other nutritional components (
Chromosomal engineering
The method is based on the possibility of replacing or adding new individual chromosomes in plants It is possible to decrease or increase the number of chromosomes in any homologous pair - aneuploidy
Animal breeding
Has a number of features in comparison with plant breeding, which objectively make it difficult to carry out 1. Only sexual reproduction is characteristic (lack of vegetative
domestication
It began about 10 - 5 thousand years ago in the Neolithic era (it weakened the effect of stabilizing natural selection, which led to an increase in hereditary variability and an increase in the selection efficiency
Crossing (hybridization)
There are two methods of crossing: related (inbreeding) and unrelated (outbreeding) When selecting a pair, the pedigrees of each manufacturer are taken into account (stud books, learn
Outbreeding (outbreeding)
Can be intrabreeding and interbreeding, interspecific or intergeneric (systematically distant hybridization) Accompanied by the effect of heterosis of F1 hybrids
Checking the breeding qualities of producers by offspring
There are economic traits that appear only in females (egg production, milk production) Males are involved in the formation of these traits in daughters (it is necessary to check males for c
Selection of microorganisms
Microorganisms (prokaryotes - bacteria, blue-green algae; eukaryotes - unicellular algae, fungi, protozoa) - are widely used in industry, agriculture, medicine
Stages of selection of microorganisms
I. The search for natural strains capable of synthesizing the products necessary for a person II. The isolation of a pure natural strain (occurs in the process of repeated seeding of
Tasks of biotechnology
1. Obtaining feed and food protein from cheap natural raw materials and industrial waste (the basis for solving the food problem) 2. Obtaining a sufficient amount
Products of microbiological synthesis
q Stern and food protein q Enzymes (widely used in food, alcohol, brewing, winemaking, meat, fish, leather, textile, etc.
Stages of the technological process of microbiological synthesis
Stage I - obtaining a pure culture of microorganisms containing only organisms of one species or strain Each species is stored in a separate test tube and goes to production and
Genetic (genetic) engineering
Genetic engineering is a field of molecular biology and biotechnology that deals with the creation and cloning of new genetic structures (recombinant DNA) and organisms with specified characteristics.
Stages of obtaining recombinant (hybrid) DNA molecules
1. Obtaining the original genetic material - the gene encoding the protein (trait) of interest The necessary gene can be obtained in two ways: artificial synthesis or extraction
Achievements in genetic engineering
The introduction of eukaryotic genes into bacteria is used for the microbiological synthesis of biologically active substances, which in nature are synthesized only by cells of higher organisms Synthesis
Problems and prospects of genetic engineering
Study of the molecular basis of hereditary diseases and the development of new methods for their treatment, finding methods for correcting damage to individual genes Increasing the resistance of the organ
Chromosomal engineering in plants
It consists in the possibility of biotechnological replacement of individual chromosomes in plant gametes or the addition of new ones In the cells of each diploid organism there are pairs of homologous chromosomes
Cell and tissue culture method
The method is the cultivation of individual cells, pieces of tissue or organs outside the body under artificial conditions on strictly sterile nutrient media with constant physical and chemical
Clonial micropropagation of plants
Cultivation of plant cells is relatively uncomplicated, the media are simple and cheap, and cell culture is unpretentious The method of plant cell culture is that a single cell or t
Hybridization of somatic cells (somatic hybridization) in plants
Protoplasts of plant cells without rigid cell walls can merge with each other, forming a hybrid cell that has the characteristics of both parents Gives the opportunity to receive
Cellular engineering in animals
Method of hormonal superovulation and embryo transplantation Isolation of dozens of eggs per year from the best cows by the method of hormonal inductive poliovulation (called
Hybridization of somatic cells in animals
Somatic cells contain the entire amount of genetic information Somatic cells for cultivation and subsequent hybridization in humans are obtained from the skin, which
Obtaining monoclonal antibodies
In response to the introduction of an antigen (bacteria, viruses, erythrocytes, etc.), the body produces specific antibodies with the help of B-lymphocytes, which are proteins called imm
Environmental Biotechnology
· Purification of water through the creation of wastewater treatment plants using biological methods q Oxidation of wastewater on biological filters q Utilization of organic and
Bioenergy
Bioenergetics is a direction of biotechnology associated with obtaining energy from biomass with the help of microorganisms One of effective methods getting energy from the biome
Bioconversion
Bioconversion is the conversion of substances formed as a result of metabolism into structurally related compounds under the action of microorganisms The goal of bioconversion is
Engineering enzymology
Engineering enzymology is a field of biotechnology that uses enzymes in the production of given substances The central method of engineering enzymology is immobilization
Biogeotechnology
Biogeotechnology - the use of the geochemical activity of microorganisms in the mining industry (ore, oil, coal) With the help of micro
The boundaries of the biosphere
Determined by a complex of factors; to general conditions the existence of living organisms include: 1. the presence of liquid water 2. the presence of a number of biogenic elements (macro- and microelements
Properties of living matter
1. They contain a huge supply of energy capable of doing work 2. The speed of chemical reactions in living matter is millions of times faster than usual due to the participation of enzymes
Functions of living matter
Performed by living matter in the process of vital activity and biochemical transformations of substances in metabolic reactions 1. Energy - transformation and assimilation by living
Land biomass
Continental part of the biosphere - land occupies 29% (148 million km2) Land heterogeneity is expressed by the presence of latitudinal zonality and altitudinal zonality
soil biomass
Soil - a mixture of decomposed organic and weathered minerals; the mineral composition of the soil includes silica (up to 50%), alumina (up to 25%), oxide of iron, magnesium, potassium, phosphorus
Biomass of the oceans
The area of the World Ocean (Earth's hydrosphere) occupies 72.2% of the entire surface of the Earth Water has special properties that are important for the life of organisms - high heat capacity and heat conductivity
Biological (biotic, biogenic, biogeochemical cycle) cycle of substances
The biotic cycle of substances is a continuous, planetary, relatively cyclic, irregular distribution of substances in time and space.
Biogeochemical cycles of individual chemical elements
Biogenic elements circulate in the biosphere, that is, they perform closed biogeochemical cycles that function under the influence of biological (life activity) and geological
nitrogen cycle
The source of N2 is molecular, gaseous, atmospheric nitrogen (it is not absorbed by most living organisms, because it is chemically inert; plants are able to assimilate only associated with ki
The carbon cycle
The main source of carbon carbon dioxide atmosphere and water The carbon cycle is carried out due to the processes of photosynthesis and cellular respiration The cycle begins with f
The water cycle
Carried out by solar energy Regulated by living organisms: 1. absorption and evaporation by plants 2. photolysis in the process of photosynthesis (decomposition
Sulfur cycle
Sulfur is a biogenic element of living matter; found in proteins as part of amino acids (up to 2.5%), is part of vitamins, glycosides, coenzymes, is found in vegetable essential oils
Energy flow in the biosphere
Source of energy in the biosphere - continuous electromagnetic radiation of the sun and radioactive energy q 42% of solar energy is reflected from clouds, dust atmosphere and the Earth's surface in
The emergence and evolution of the biosphere
Living matter, and with it the biosphere, appeared on Earth as a result of the emergence of life in the process of chemical evolution about 3.5 billion years ago, which led to the formation of organic substances
Noosphere
The noosphere (literally, the sphere of the mind) is the highest stage in the development of the biosphere, associated with the emergence and formation of civilized humanity in it, when its mind
Signs of the modern noosphere
1. Increasing amount of recoverable materials of the lithosphere - growth in the development of mineral deposits (now it exceeds 100 billion tons per year) 2. Mass consumption
Human influence on the biosphere
The current state of the noosphere is characterized by an ever-increasing prospect of an ecological crisis, many aspects of which are already manifesting themselves in full, creating a real threat to the existence
Energy production
q The construction of hydroelectric power plants and the creation of reservoirs causes flooding of large areas and the resettlement of people, raising the level ground water, erosion and waterlogging of the soil, landslides, loss of arable land
Food production. Depletion and pollution of the soil, reduction of the area of fertile soils
q Arable land covers 10% of the Earth's surface (1.2 billion ha) q Cause - overexploitation, imperfection of agricultural production: water and wind erosion and the formation of ravines, in
Reduction of natural biological diversity
q Human economic activity in nature is accompanied by a change in the number of animal and plant species, the extinction of entire taxa, and a decrease in the diversity of living things.
acid rain
q Increased acidity of rains, snow, fogs due to the emission of sulfur and nitrogen oxides from fuel combustion into the atmosphere q Acid precipitation reduces crops, destroys natural vegetation
Ways to solve environmental problems
In the future, a person will exploit the resources of the biosphere on an ever-increasing scale, since this exploitation is an indispensable and main condition for the very existence of h
Sustainable consumption and management of natural resources
q The most complete and comprehensive extraction of all minerals from the fields (due to the imperfection of the extraction technology, only 30-50% of the reserves are extracted from oil fields q Rec
Ecological strategy for the development of agriculture
q Strategic direction - increasing crop yields to feed a growing population without increasing acreage q Increasing crop yields without negative
Properties of living matter
1. Unity of the elementary chemical composition(98% is carbon, hydrogen, oxygen and nitrogen) 2. Unity biochemical composition- all living organisms
Hypotheses for the origin of life on Earth
There are two alternative concepts of the possibility of the origin of life on Earth: q abiogenesis - the emergence of living organisms from substances of inorganic nature
Stages of the development of the Earth (chemical prerequisites for the emergence of life)
1. The stellar stage of the Earth's history q The geological history of the Earth began more than 6 years ago. years ago, when the Earth was a red-hot over 1000
The emergence of the process of self-reproduction of molecules (biogenic matrix synthesis of biopolymers)
1. Occurred as a result of the interaction of coacervates with nucleic acids 2. All the necessary components of the process of biogenic matrix synthesis: - enzymes - proteins - pr
Prerequisites for the emergence of the evolutionary theory of Ch. Darwin
Socio-economic background 1. In the first half of the XIX century. England has become one of the most economically developed countries in the world with a high level of
· Set out in the book of Ch. Darwin "On the origin of species by natural selection or the preservation of favored breeds in the struggle for life", which was published
Variability
Substantiation of the variability of species To substantiate the position on the variability of living beings, Charles Darwin used common
Correlative (relative) variability
A change in the structure or function of one part of the body causes a coordinated change in the other or others, since the body is an integral system, the individual parts of which are closely interconnected
The main provisions of the evolutionary teachings of Ch. Darwin
1. All kinds of living creatures inhabiting the Earth have never been created by anyone, but arose naturally 2. Having arisen naturally, species slowly and gradually
The development of ideas about the form
Aristotle - used the concept of species when describing animals, which had no scientific content and was used as a logical concept D. Ray
Species criteria (signs of species identification)
Significance of species criteria in science and practice - determination of species belonging of individuals (species identification) I. Morphological - similarity of morphological inheritances
Population types
1. Panmictic - consist of individuals that reproduce sexually, cross-fertilized. 2. Clonial - from individuals that breed only without
mutation process
Spontaneous changes in the hereditary material of germ cells in the form of gene, chromosome and genomic mutations occur constantly throughout the entire period of life under the influence of mutations
Insulation
Isolation - cessation of the flow of genes from population to population (limitation of the exchange of genetic information between populations) The value of isolation as a fa
Primary insulation
Not directly related to the action of natural selection, is a consequence external factors Leads to a sharp decrease or cessation of migration of individuals from other populations
Environmental isolation
· Arises on the basis of ecological differences in the existence of different populations (different populations occupy different ecological niches) v For example, the trout of Lake Sevan
Secondary isolation (biological, reproductive)
Is of decisive importance in the formation of reproductive isolation Arises as a result of intraspecific differences in organisms Arose as a result of evolution Has two iso
Migrations
Migrations - the movement of individuals (seeds, pollen, spores) and their characteristic alleles between populations, leading to a change in the frequencies of alleles and genotypes in their gene pools
population waves
Population waves ("waves of life") - periodic and non-periodic sharp fluctuations in the number of individuals in a population under the influence of natural causes (S. S.
Significance of population waves
1. Leads to an undirected and abrupt change in the frequencies of alleles and genotypes in the gene pool of populations (random survival of individuals during the wintering period can increase the concentration of this mutation by 1000 r
Gene drift (genetic-automatic processes)
Genetic drift (genetic-automatic processes) - random non-directional, not due to the action of natural selection, change in the frequencies of alleles and genotypes in m
The result of genetic drift (for small populations)
1. Causes the loss (p = 0) or fixation (p = 1) of alleles in the homozygous state in all members of the population, regardless of their adaptive value - homozygotization of individuals
Natural selection is the guiding factor of evolution
Natural selection is the process of preferential (selective, selective) survival and reproduction of the fittest individuals and non-survival or non-reproduction
Struggle for existence Forms of natural selection
Driving selection (Described by C. Darwin, modern teaching developed by D. Simpson, English) Driving selection - selection in
Stabilizing selection
· The theory of stabilizing selection was developed by the Russian acad. I. I. Shmagauzen (1946) Stabilizing selection - selection acting in stable
Other forms of natural selection
Individual selection - selective survival and reproduction of individuals that have an advantage in the struggle for existence and elimination of others
The main features of natural and artificial selection
Natural selection Artificial selection 1. Arose with the emergence of life on Earth (about 3 billion years ago) 1. Arose in the
Common features of natural and artificial selection
1. Initial (elementary) material - individual characteristics of the organism (hereditary changes - mutations) 2. Carried out according to the phenotype 3. Elementary structure - population
The struggle for existence is the most important factor in evolution
The struggle for existence is a complex relationship of an organism with abiotic (physical conditions of life) and biotic (relations with other living organisms) fact
Reproduction intensity
v One roundworm produces 200 thousand eggs per day; the gray rat gives 5 litters per year, 8 rats, which become sexually mature at the age of three months; offspring of one daphnia per summer
Interspecies struggle for existence
Occurs between individuals of populations of different species Less acute than intraspecific, but its intensity increases if different types occupy similar ecological niches and have
Fight against adverse abiotic environmental factors
Observed in all cases when individuals of the population are in extreme physical conditions(excessive heat, drought, harsh winter, excessive moisture, infertile soils, harsh
The main discoveries in the field of biology after the creation of STE
1. Discovery of the hierarchical structures of DNA and protein, including the secondary structure of DNA - the double helix and its nucleoprotein nature 2. Deciphering the genetic code (its triplet
Signs of the organs of the endocrine system
1. They are relatively small in size (fractions or a few grams) 2. Anatomically unrelated 3. Synthesize hormones 4. Have an abundant network of blood vessels
Characteristics (signs) of hormones
1. Formed in the endocrine glands (neurohormones can be synthesized in neurosecretory cells) 2. High biological activity - the ability to quickly and strongly change the int
The chemical nature of hormones
1. Peptides and simple proteins (insulin, somatotropin, adenohypophysis tropic hormones, calcitonin, glucagon, vasopressin, oxytocin, hypothalamic hormones) 2. Complex proteins - thyrotropin, lute
Hormones of the middle (intermediate) share
Melanotropic hormone (melanotropin) - the exchange of pigments (melanin) in integumentary tissues Hormones of the posterior lobe (neurohypophysis) - oxytrcin, vasopressin
Thyroid hormones (thyroxine, triiodothyronine)
The composition of thyroid hormones certainly includes iodine and the amino acid tyrosine (0.3 mg of iodine is secreted daily in the hormones, therefore a person must receive daily with food and water
Hypothyroidism (hypothyroidism)
The cause of hypotherosis is a chronic deficiency of iodine in food and water. The lack of hormone secretion is compensated by the growth of the gland tissue and a significant increase in its volume.
Cortical hormones (mineralcorticoids, glucocorticoids, sex hormones)
The cortical layer is formed from epithelial tissue and consists of three zones: glomerular, fascicular and reticular, which have different morphology and functions. Hormones related to steroids - corticosteroids
Adrenal medulla hormones (epinephrine, norepinephrine)
- The medulla consists of special yellow-staining chromaffin cells (these cells are located in the aorta, the branching point of the carotid artery and in the sympathetic nodes; they are all
Pancreatic hormones (insulin, glucagon, somatostatin)
Insulin (secreted by beta cells (insulocytes), is the simplest protein) Functions: 1. Regulation carbohydrate metabolism(the only sugar lowering
Testosterone
Functions: 1. Development of secondary sexual characteristics (body proportions, muscles, growth of a beard, body hair, mental characteristics of a man, etc.) 2. Growth and development of reproductive organs
ovaries
1. Paired organs (sizes about 4 cm, weight 6-8 grams), located in the small pelvis, on both sides of the uterus 2. Consist of a large number (300-400 thousand) so-called. follicles - structure
Estradiol
Functions: 1. Development of female genital organs: oviducts, uterus, vagina, mammary glands 2. Formation of female secondary sexual characteristics (body build, figure, fat deposition, in
Endocrine glands (endocrine system) and their hormones
Endocrine glands Hormones Functions Pituitary gland: - anterior lobe: adenohypophysis - middle lobe - posterior
Reflex. reflex arc
Reflex - the body's response to irritation (change) of the external and internal environment, carried out with the participation of the nervous system (the main form of activity
Feedback mechanism
The reflex arc does not end with the body's response to irritation (by the work of the effector). All tissues and organs have their own receptors and afferent nerve pathways suitable for sensory
Spinal cord
1. The most ancient part of the CNS of vertebrates (first appears in the cephalochordates - the lancelet) 2. In the process of embryogenesis, it develops from the neural tube 3. It is located in the bone
Skeletal motor reflexes
1. Patellar reflex (the center is localized in the lumbar segment); vestigial reflex from animal ancestors 2. Achilles reflex (in the lumbar segment) 3. Plantar reflex (with
Conductor function
The spinal cord has a two-way connection with the brain (stem and cerebral cortex); through the spinal cord, the brain is connected with the receptors and executive organs of the body
Brain
The brain and spinal cord develop in the embryo from the outer germ layer - ectoderm It is located in the cavity of the brain skull It is covered (like the spinal cord) by three shells
Medulla
2. In the process of embryogenesis, it develops from the fifth cerebral bladder of the neural tube of the embryo 3. It is a continuation of the spinal cord (the lower boundary between them is the exit site of the root
reflex function
1. Protective reflexes: coughing, sneezing, blinking, vomiting, tearing 2. Food reflexes: sucking, swallowing, digestive juice secretion, motility and peristalsis
midbrain
1. In the process of embryogenesis from the third cerebral vesicle of the neural tube of the embryo 2. Covered with white matter, gray matter inside in the form of nuclei 3. Has the following structural components
Functions of the midbrain (reflex and conduction)
I. Reflex function (all reflexes are innate, unconditioned) 1. Regulation of muscle tone during movement, walking, standing 2. Orienting reflex
Thalamus (optical tubercles)
Represents paired accumulations of gray matter (40 pairs of nuclei), covered with a layer of white matter, inside - the III ventricle and reticular formation All nuclei of the thalamus are afferent, senses
Functions of the hypothalamus
1. The highest center of the nervous regulation of the cardiovascular system, the permeability of blood vessels 2. The center of thermoregulation 3. The regulation of the water-salt balance of the body
Functions of the cerebellum
The cerebellum is connected to all parts of the central nervous system; skin receptors, proprioceptors of the vestibular and locomotive system, subcortex and cerebral cortex Functions of the cerebellum explore the way
Telencephalon (large brain, large hemispheres of the forebrain)
1. In the process of embryogenesis, it develops from the first cerebral bladder of the neural tube of the embryo 2. It consists of two hemispheres (right and left), separated by a deep longitudinal fissure and connected
Cerebral cortex (cloak)
1. In mammals and humans, the surface of the cortex is folded, covered with convolutions and furrows, providing an increase in surface area (in humans it is about 2200 cm2
Functions of the cerebral cortex
Study methods: 1. Electrical stimulation of individual areas (the method of “implanting” electrodes into brain areas) 3. 2. Removal (extirpation) of individual areas
Sensory zones (areas) of the cerebral cortex
They are the central (cortical) sections of the analyzers, sensitive (afferent) impulses from the corresponding receptors are suitable for them Occupy a small part of the cortex
Functions of association zones
1. Communication between different areas of the cortex (sensory and motor) 2. Unification (integration) of all sensitive information entering the cortex with memory and emotions 3. Decisive
Features of the autonomic nervous system
1. It is divided into two sections: sympathetic and parasympathetic (each of them has a central and peripheral parts) 2. It does not have its own afferent (
Features of the departments of the autonomic nervous system
Sympathetic department Parasympathetic department 1. The central ganglia are located in the lateral horns of the thoracic and lumbar segments of the spinal
Functions of the autonomic nervous system
Most of the organs of the body are innervated by both the sympathetic and parasympathetic systems (dual innervation) Both departments have three kinds of actions on the organs - vasomotor,
Influence of the sympathetic and parasympathetic division of the autonomic nervous system
Sympathetic department Parasympathetic department 1. Accelerates the rhythm, increases the force of heart contractions 2. Expands the coronary vessels of the
Higher nervous activity of a person
Mental mechanisms Reflections: Mental Mechanisms for Designing the Future - Feel
Features (signs) of unconditioned and conditioned reflexes
Unconditioned reflexes Conditioned reflexes
Methodology for the development (formation) of conditioned reflexes
Developed by I.P. Pavlov on dogs in the study of salivation under the action of light or sound stimuli, odors, touches, etc. (the salivary gland duct was brought out through the opening
Conditions for the development of conditioned reflexes
1. An indifferent stimulus must precede the unconditioned one (anticipatory action) 2. The average strength of an indifferent stimulus (with low and high strength, the reflex may not form
The meaning of conditioned reflexes
1. Underlying training, obtaining physical and mental skills 2. Subtle adaptation of vegetative, somatic and mental reactions to conditions with
Induction (external) braking
o Develops under the action of a foreign, unexpected, strong stimulus from the external or internal environment v Strong hunger, overcrowded bladder, pain or sexual arousal
Fading Conditional Inhibition
Develops with a systematic non-reinforcement of the conditioned stimulus with an unconditioned stimulus v If the conditioned stimulus is repeated at short intervals without reinforcing it without
Relationship between excitation and inhibition in the cerebral cortex
Irradiation - the spread of processes of excitation or inhibition from the focus of their occurrence to other areas of the cortex An example of the irradiation of the process of excitation
Causes of sleep
There are several hypotheses and theories of the causes of sleep: Chemical hypothesis - the cause of sleep is the poisoning of brain cells with toxic waste products, the image
REM (paradoxical) sleep
Comes after a period of slow sleep and lasts 10-15 minutes; then again replaced by slow sleep; repeated 4-5 times during the night Characterized by rapid
Features of higher nervous activity of a person
(differences from the GNI of animals) The channels for obtaining information about the factors of the external and internal environment are called signaling systems The first and second signaling systems are distinguished
Features of higher nervous activity of man and animals
Animal Man 1. Obtaining information about environmental factors only with the help of the first signaling system (analyzers) 2. Specific
Memory as a component of higher nervous activity
Memory is a set of mental processes that ensure the preservation, consolidation and reproduction of previous individual experience v Basic memory processes
Analyzers
All information about the external and internal environment of the body, necessary for interaction with it, a person receives with the help of the senses (sensory systems, analyzers) v The concept of analysis
Structure and functions of analyzers
Each analyzer consists of three anatomically and functionally related sections: peripheral, conductive and central Damage to one of the parts of the analyzer
The value of analyzers
1. Information to the body about the state and changes in the external and internal environment 2. The emergence of sensations and the formation on their basis of concepts and ideas about the world, i.e. e.
Choroid (middle)
Located under the sclera, rich in blood vessels, consists of three parts: the anterior - the iris, the middle - the ciliary body and the posterior - the vascular itself
Features of the photoreceptor cells of the retina
Rods Cones 1. Quantity 130 million 2. Visual pigment - rhodopsin (visual purple) 3. Maximum amount on n
lens
· Located behind the pupil, has the shape of a biconvex lens with a diameter of about 9 mm, absolutely transparent and elastic. Covered with a transparent capsule, to which the zinnia ligaments of the ciliary body are attached
The functioning of the eye
Visual reception begins with photochemical reactions that begin in the rods and cones of the retina and consist in the breakdown of visual pigments under the action of light quanta. Exactly this
Vision hygiene
1. Injury prevention (goggles at work with traumatic objects - dust, chemicals, chips, splinters, etc.) 2. Eye protection from too bright light - sun, electric
outer ear
Representation of the auricle and external auditory canal The auricle - freely protruding on the surface of the head
Middle ear (tympanic cavity)
Lies inside the pyramid of the temporal bone Filled with air and communicates with the nasopharynx through a tube 3.5 cm long and 2 mm in diameter - the Eustachian tube Eustachian function
inner ear
It is located in the pyramid of the temporal bone It includes a bone labyrinth, which is a complex structure of channels Inside the bone
Perception of sound vibrations
The auricle picks up sounds and directs them to the external auditory canal. Sound waves cause vibrations of the tympanic membrane, which are transmitted from it through the system of levers of the auditory ossicles (
Hearing hygiene
1. Prevention of hearing injuries 2. Protection of the hearing organs from excessive strength or duration of sound stimuli - the so-called. "noise pollution", especially in noisy environments
biospheric
1. Represented by cellular organelles 2. Biological mesosystems 3. Mutations are possible 4. Histological research method 5. Beginning of metabolism 6. About
"Structure of a eukaryotic cell" 9. Cell organoid containing DNA 10. Has pores 11. Performs a compartmental function in the cell 12. Function
Cell Center
Verification thematic digital dictation on the topic "Cell Metabolism" 1. Carried out in the cytoplasm of the cell 2. Requires specific enzymes
Thematic digital programmed dictation
on the topic "Energy exchange" 1. Hydrolysis reactions are carried out 2. End products - CO2 and H2 O 3. End product - PVC 4. NAD is restored
oxygen stage
Thematic digital programmed dictation on the topic "Photosynthesis" 1. Photolysis of water is carried out 2. Recovery occurs
Cell Metabolism: Energy Metabolism. Photosynthesis. Protein biosynthesis” 1. Carried out in autotrophs 52. Transcription is carried out 2. Associated with the functioning
The main features of the kingdoms of eukaryotes
Kingdom of Plants Kingdom of Animals 1. They have three sub-kingdoms: - lower plants (true algae) - red algae
Features of types of artificial selection in breeding
Mass selection Individual selection 1. Many individuals with the most pronounced hosts are allowed to breed.
Common features of mass and individual selection
1. Carried out by man with artificial selection 2. Only individuals with the most pronounced desired trait are allowed for further reproduction 3. Can be repeated
