Morphofunctional characteristics of x and y human chromosomes. Molecular organization of chromosomes
The set of chromosomes of a somatic cell that characterizes an organism of a given species is called karyotype (Fig. 2.12).
Rice. 2.12. Karyotype ( A) and idiogram ( b) human chromosomes
Chromosomes are divided into autosomes(the same for both sexes) and heterochromosomes, or sex chromosomes(different set for males and females). For example, a human karyotype contains 22 pairs of autosomes and two sex chromosomes - XX in a woman and XY y men (44+ XX and 44+ XY respectively). The somatic cells of organisms contain diploid (double) set of chromosomes, and gametes - haploid (single).
Idiogram- this is a systematized karyotype, in koto-1M chromosomes are located as their size decreases. It is not always possible to accurately arrange chromosomes in size, since some pairs of chromosomes have similar sizes. Therefore, in 1960 it was proposed Denver classification of chromosomes, which, in addition to size, takes into account the shape of the chromosomes, the position of the centromere, and the presence of secondary constrictions and satellites (Fig. 2.13). According to this classification, 23 pairs of human chromosomes were divided into 7 groups - from A to G. An important feature that facilitates classification is centromeric index(CI), which reflects the ratio (in percent) of the length of the short arm to the length of the entire chromosome.
Rice. 2.13. Denver classification of human chromosomes
Consider groups of chromosomes.
Group A (chromosomes 1-3). These are large, metacentric and submetacentric chromosomes, their centromeric index is from 38 to 49. The first pair of chromosomes is the largest metacentric (CI 48-49), in the proximal part of the long arm near the centromere there may be a secondary constriction. The second pair of chromosomes is the largest submetacentric (CI 38-40). The third pair of chromosomes is 20% shorter than the first, the chromosomes are submetacentric (CI 45-46), easily identified.
Group B (chromosomes 4 and 5). These are large submetacentric chromosomes, their centromeric index is 24-30. They do not differ from each other with normal staining. The distribution of R- and G-segments (see below) is different for them.
Group C (chromosomes 6-12). Chromosomes of average size j measure, submetacentric, their centromeric index 27-35. In the 9th chromosome, a secondary constriction is often found. This group also includes the X chromosome. All chromosomes of this group can be identified using Q- and G-staining.
Group D (chromosomes 13-15). Chromosomes are acrocentric, very different from all other human chromosomes, their centromeric index is about 15. All three pairs have satellites. The long arms of these chromosomes differ in Q- and G-segments.
Group E (chromosomes 16-18). The chromosomes are relatively short, metacentric or submetacentric, their centromeric index is from 26 to 40 (chromosome 16 has a CI of about 40, chromosome 17 has a CI of 34, chromosome 18 has a CI of 26). In the long arm of the 16th chromosome, a secondary constriction is detected in 10% of cases.
Group F (chromosomes 19 and 20). Chromosomes are short, submetacentric, their centromeric index is 36-46. With normal staining, they look the same, but with differential staining, they are clearly distinguishable.
Group G (chromosomes 21 and 22). Chromosomes are small, acrocentric, their centromeric index is 13-33. This group also includes the Y chromosome. They are easily distinguishable by differential staining.
At the core Parisian classification of human chromosomes (1971) are methods of their special differential staining, in which each chromosome reveals its characteristic order of alternation of transverse light and dark segments (Fig. 2.14).
Rice. 2.14. Parisian classification of human chromosomes
Different types of segments are designated by the methods by which they are identified most clearly. For example, Q-segments are sections of chromosomes that fluoresce after staining with quinacrine mustard; segments are identified by Giemsa staining (Q- and G-segments are identical); R-segments are stained after controlled heat denaturation, etc. These methods make it possible to clearly differentiate human chromosomes within groups.
The short arm of chromosomes is denoted by the Latin letter p and the long q. Each chromosome arm is divided into regions numbered from centromere to telomere. In some short arms, one such region is distinguished, and in others (long) - up to four. The bands within the regions are numbered in order from the centromere. If the localization of the gene is precisely known, the band index is used to designate it. For example, the localization of the gene encoding esterase D is denoted 13 p 14, i.e., the fourth band of the first region of the short arm of the thirteenth chromosome. The localization of genes is not always known up to the band. Thus, the location of the retinoblastoma gene is indicated by 13 q, which means its localization in the long arm of the thirteenth chromosome.
The main functions of chromosomes are the storage, reproduction and transmission of genetic information during the reproduction of cells and organisms.
Examination No. 3
“Cell nucleus: main components of the nucleus, their structural and functional characteristics. The hereditary apparatus of the cell. Temporal organization of hereditary material: chromatin and chromosomes. The structure and functions of chromosomes. The concept of karyotype.
Patterns of cell existence in time. Reproduction at the cellular level: mitosis and meiosis. The concept of apoptosis»
Questions for self-preparation:
The role of the nucleus and cytoplasm in the transmission of hereditary information; Characterization of the nucleus as a genetic center. The role of chromosomes in the transmission of hereditary information. Chromosome rules; Cytoplasmic (extranuclear) heredity: plasmids, episomes, their significance in medicine; The main components of the nucleus, their structural and functional characteristics. Modern ideas about the structure of chromosomes: nucleosome model of chromosomes, levels of DNA organization in chromosomes; Chromatin as a form of existence of chromosomes (hetero - and euchromatin): structure, chemical composition; Karyotype. Classification of chromosomes (Denver and Parisian). Types of chromosomes; The life cycle of a cell, its periods, its variants (features in different types of cells). The concept of stem, resting cells. Mitosis is a characteristic of its periods. regulation of mitosis. Morphofunctional characteristics and dynamics of chromosome structure in the cell cycle. The biological significance of mitosis. The concept of apoptosis. Categories of cell complexes. mitotic index. The concept of mitogens and cytostatics.
PART 1. Independent work:
Task number 1. Key concepts of the topic
Select the appropriate terms from the list and distribute them in the left column of Table 1, according to the definitions.
Metaphase chromosomes, Metacentric chromosomes, Acrocentric chromosomes; Meiosis; Sperm; spermatocyte; cytokinesis; Binary division; spermatogenesis; spermatogonia; Mitosis; monospermia; schizogony; Endogony; Ovogenesis; Amitosis; apoptosis; isogamy; gametogenesis; sporulation; gametes; Haploid set of chromosomes; cytokinesis; Ovogonia (oogonia); Anisogamy; Ovotida (ovum); Fertilization; Parthenogenesis; Ovogamia; Fragmentation; Hermaphroditism; The life cycle of a cell; Interphase; Cellular (mitotic cycle).
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this is a direct cell division, in which there is no uniform distribution of hereditary material between daughter cells |
part of the cell life cycle during which a differentiated cell performs its functions and prepares for division |
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Task number 2. "The degree of helix chromatin and localization of chromatin in the nucleus".
Based on the materials of the lecture and the textbook "Cytology" 1) study the chromatin depending on the degree of its spiralization and fill in the diagram:
2) study the chromatin depending on the localization in the nucleus and fill in the diagram:
PART 2. Practical work:
Task number 1. Study the person's karyogram below and answer the following questions in writing:
1) Chromosomal set of what sex (male or female) does the karyogram reflect? Explain the answer.
2) Specify the number of autosomes and sex chromosomes shown on the karyogram.
3) What type of chromosomes does the Y chromosome belong to?
Determine the gender and write the word in the box, explain your answer:
"Human Kariogram"
Answer with explanation: |
PART 3. Problem-situational tasks:
1. The synthesis of histone proteins is impaired in the cell. What consequences can this have for the cell?
2. On the micropreparation, non-identical two- and multi-nuclear cells were found, some of which did not contain nuclei at all. What process underlies their formation? Define this process.
In the microscopic analysis of chromosomes, first of all, their differences in shape and size are visible. The structure of each chromosome is purely individual. It can also be seen that chromosomes have common morphological features. They consist of two strands - chromatid, located in parallel and interconnected at one point, called centromere or primary stretch. On some chromosomes, one can see secondary stretch. It is a characteristic feature that allows you to identify individual chromosomes in a cell. If the secondary constriction is located close to the end of the chromosome, then the distal region bounded by it is called satellite. Chromosomes containing a satellite are referred to as AT chromosomes. On some of them, the formation of nucleoli occurs in the body phase.
The ends of chromosomes have a special structure and are called telomeres. Telomere regions have a certain polarity that prevents them from connecting to each other when broken or with the free ends of chromosomes. The section of chromatid (chromosome) from telomere to centromere is called arm of the chromosome. Each chromosome has two arms. Depending on the ratio of the lengths of the arms, three types of chromosomes are distinguished: 1) metacentric(equal-arms); 2) submetacentric(unequal shoulders); 3) acrocentric, in which one shoulder is very short and not always clearly distinguishable.
At the Paris Conference on the Standardization of Karyotypes, instead of the morphological terms "metacentrics" or "acrocentrics", in connection with the development of new methods for obtaining "striped" chromosomes, a symbolism was proposed in which all chromosomes of a set are assigned a rank (serial number) in descending order of magnitude and in both On the shoulders of each chromosome (p - short arm, q - long arm), sections of the arms and stripes in each section are numbered in the direction from the centromere. Such a notation allows a detailed description of chromosome anomalies.
Along with the location of the centromere, the presence of a secondary constriction and a satellite, their length is important for determining individual chromosomes. For each chromosome of a certain set, its length remains relatively constant. Measurement of chromosomes is necessary to study their variability in ontogeny in connection with diseases, anomalies, and impaired reproductive function.
Fine structure of chromosomes. Chemical analysis of the structure of chromosomes showed the presence of two main components in them: deoxyribonucleic acid(DNA) and protein type histones And protomite(in sex cells). Studies of the fine submolecular structure of chromosomes led scientists to the conclusion that each chromatid contains one strand - lameness. Each chromoneme consists of one DNA molecule. The structural basis of the chromatid is a strand of protein nature. Chromonema is arranged in a chromatid in a shape close to a spiral. Evidence of this assumption was obtained, in particular, in the study of the smallest exchange particles of sister chromatids, which were located across the chromosome.
The flow of information in the cell, protein biosynthesis and its regulation. Plastic and energy metabolism.
Cell theory, its provisions and main stages of development (M. Schleiden, T. Schwann, R. Virchow). The current state of cell theory and its implications for medicine.
Human karyotype. Morphofunctional characteristics and classification of human chromosomes. The role of studying the karyotype for the detection of human pathology.
Medico-biological aspects of human environmental problems.
Organization of open biological systems in space and time.
Patterns of the manifestation of the properties of living things in the development and structural and functional organization of organs and tissues of the human body.
Tasks of human biology as a basic discipline in the system of natural science and professional training of a general practitioner.
The body as an open self-regulating system. The concept of homeostasis. Theory genetic, cellular and systemic bases of homeostasis.
The historical method and the modern systematic approach are the basis for the knowledge of the general laws and patterns of human life.
Prokaryotypic and eukaryotic cells, their comparative characteristics.
Fundamental properties of life, their diversity and attributes of life.
Creation of the chromosome theory of heredity.
molecular organization of organic substances (proteins, carbohydrates, nucleic acids, ATP) and their role.
Development of ideas about the essence of life. Definition of life from the standpoint of a systematic approach (vitalism, mechanism, dialectical materialism).
Immunity as a property of maintaining the individuality of organisms and diversity within a species. Types of immunity.
Background and modern ideas about the origin of life on Earth.
The law of physical and chemical unity of living matter V.I. Vernadsky. Natural biogenic elements.
Differences in the life cycles of normal and tumor cells. Regulation of the cell cycle and mitotic activity.
Patterns of the flow of substances in pro- and eukaryotic cells.
Features of the flow of information in pro- and eukaryotic cells.
Age-related changes in various tissues, organs in the human system.
Discretion and integrity. Living beings are a discrete form of life, as diversity and a single principle of organization.
Biological sciences, their tasks, objects and levels of knowledge.
History and modern stage of development of biology.
A cell is a genetic and structural and functional unit of a multicellular organism. The emergence of cellular organization in the process of evolution.
Features of energy flow in pro- and eukaryotic cells.
Communication of biology with other natural sciences. Genetics, ecology, chronobiology as social disciplines.
Structures and functions of the plasmalemma. Transport of substances through the plasmalemma.
Manifestations of the fundamental properties of living things at the main evolutionary-conditioned levels of organization. Hierarchy of levels of organization of living organisms.
General patterns of embryonic development: zygote, cleavage, gastrulation, histo- and organogenesis. Types of placenta.
Insemination. Fertilization. Parthenogenesis. Androgenesis. Biological features of human reproduction.
postembryonic anthogenesis. Periodization of postembryonic ontogenesis in humans.
modification variability. The norm of the reaction, its genetic determinism. Modification variability in humans.
Cell cycle, its periodization. mitotic cycle. Dynamics of the structure of chromosomes in the mitotic cycle.
Rules of uniformity and the law of splitting. dominance and recessiveness.
mutational variability. A mutation is a qualitative or quantitative change in genetic material. Mutation classification, brief description.
Biological aspects of the structure, death. Theory of aging. Molecular genetic cellular and systemic mechanisms of aging. Longevity problems.
The sexual process as a mechanism for the exchange of hereditary information within a species. Evolution of forms of sexual reproduction.
Proliferation and differentiation of cells, activation, differential inclusion of genes, embryonic induction.
Mitosis and its biological significance. DNA replication. Mitotic activity in cells of various tissues of organs of the human body.
Molecular and cellular bases of reproduction of organisms. The evolution of reproduction.
Genetic code: its properties and concept.
Egg shells of vertebrates and their biological significance. Types of eggs. The structure of the human egg.
Human genetics. The main methods of human genetics: genealogical, twin, cytogenetic, population-statistical, cultivation of somatic cells, DNA research using "probes", etc.
Biological role and forms of asexual reproduction. Evolution of forms of asexual reproduction. Meiosis, cytological and cytogenetic characteristics. biological significance. Essence.
Meiosis. Cytological and cytogenetic characteristics. biological significance. Essence.
Relative biological expediency of a biological species. Speciation, methods and ways.
Teratogenesis. Phenocopin. Hereditary and non-hereditary malformations of the human body, as a result of dysregulation of ontogenesis.
Structural and functional levels of organization of genetic material gene chromosomal, genomic. A gene is a functional unit of heredity. Structure, functions and regulation of the action of genes in prokaryotes and eukaryotes. Discontinuity of genes.
Critical periods of ontogeny. The role of environmental factors in ontogeny.
The nuclear apparatus is the control system of the cell. Chromosomes. Structure and functions. Types of chromosomes. DNA packaging levels in chromosomes.
Heredity and variability are fundamental, universal properties of living things. Heredity. As a property that provides material continuity between generations.
Chromosomal theory of sex determination. Inheritance of sex-linked traits.
The role of the nervous, endocrine and immune systems in ensuring the constancy of the internal environment and adaptive changes.
Immunological mechanisms of tissues. Organs and system of human organs.
Genetic cargo, its biological essence. Principles of population ecology. Definition and types of ontogeny. Periodization of ontogeny.
Definition and types of ontogeny. Periodization of ontogeny.
Genotype as a single integral historical system. Phenotype, as a result of the implementation of the genotype in certain environmental conditions. penetrance and expressivity.
Sexual dimorphism: genetic, morphophysiological, endocrine and behavioral aspects.
Regeneration of organs and tissues as a process of development. Physiological and reparative regeneration. Mechanisms and regulation of regeneration.
Mutagenesis in humans. Mutational variability and evolution. The manifestation and role of mutations in pathogenetic manifestations in humans.
Formation, development and formation of tissues, organs, organ systems in human embryogenesis. Transformation of the gill apparatus.
Preembryonic (prozygotic), embryonic (atenatal) and postembryonic (postnatal) periods of development.
Ch. Darwin's theory of evolution (evolutionary material, factors of evolution).
Phylogeny of the excretory system.
Prospects for genetic engineering in the treatment of genetic diseases. Prevention of hereditary diseases.
Population structure of the species. Population as an elementary evolutionary unit. population criteria.
Types of inheritance. Monogenic inheritance. The concept of alleles, homozygosity, heterozygosity.
Hybridization, importance for the development of genetics. Di- and poly-hybrid crosses. The law of independent feature splitting.
Variability as a property that provides the possibility of the existence of living organisms in various states. Variation forms.
Class Crustacea. Higher and lower crayfish are intermediate hosts of human helminths. Structure and meaning.
The concept of biological evolution. Formation of evolutionary ideas in the pre-Darwinian period.
Connection of individual and historical development. biogenetic law. Theory of phyloembryogenesis A.N. Severtsov.
Population-genetic effects of natural selection, stabilization of the gene pool of populations, maintenance of the state of genetic polymorphism over time.
The significance of the works of N.I. Vavilova, N.K. Koltsova, S.S. Chetverikova, A.S. Serebrovsky and other prominent Russian genetic scientists in the development of the national genetic school.
The subject of biology. Biology, as a science about the living nature of the planet, about the general patterns of life phenomena and the mechanisms of life and development of living organisms.
Subject, tasks and methods of genetics. The value of genetics for the training of physicians and medicine in general. Stages of development of genetics. Mendel is the founder of modern genetics.
Interaction of allelic genes: complete dominance, recessiveness, incomplete demination, codominance. Examples.
Phylogeny of the respiratory system.
The concept of V.I. Vernadsky about the biosphere. Ecological succession as the main event in the evolution of ecosystems.
Forms of natural selection. Its adaptive value, pressure and selection coefficients. The leading and creative role of natural selection.
Population structure of mankind. People - as an object of action of evolutionary factors. Drift of genes and features of gene pools of insulators.
Food chains, ecological pyramid. Energy flow. Biogeocenosis. Anthropocenosis. The role of V.N. Sukachev in the study of biogeocenosis.
Phylogeny of the endocrine system.
The contribution of Russian scientists to the development of the theory of biological evolution. Prominent domestic evolutionists.
Phylogeny of the reproductive system.
Microevolution. Rules and methods of group evolution. General patterns, directions and ways of evolution.
Phylogeny of the circulatory system.
Early diagnosis of chromosomal diseases and their manifestation in the human body. Consequences of related marriages for the manifestation of hereditary pathology in humans.
Type of arthropods, value in medicine. Characteristics and classification of the type. Features of the structure of the main representatives of classes of epidemiological significance.
Biological and social aspects of human and population adaptation in the conditions of life activity. The consequent nature of human adaptation. Man as a creative ecological factor.
100. Medical genetics. The concept of hereditary diseases. The role of the environment in their appearance. Genetic and chromosomal diseases, their frequency.
101. Lethal and field-lethal action of genes. Multiple allelism. Pleiotropy. Inheritance of a person's blood group.
102. Chromosomes as linkage groups of genes. Genome is a species, genetic system. Genotypes and phenotypes.
103. Class of infusoria.
105. Man and biosphere. Man - as a natural object, and the biosphere. As a habitat and source of resources. Characteristics of natural resources.
106. Biological variability of people and biological characteristics. The concept of ecological types of people. Conditions of their formation in the historical development of mankind.
108. Phylogeny of the nervous system.
109. Class Flukes. General characteristics of the class, development cycles, ways of infection, pathogenic effects, substantiation of laboratory diagnostics and prevention methods.
110. Class Insects: external and internal structure, classification. medical significance.
111. The contribution of Russian scientists to the development of the doctrine of the biosphere. Problems of environmental protection and the survival of mankind.
112. Class tapeworms. Morphology, development cycles, ways of infection, pathogenic impact, basic methods of laboratory diagnostics
113. Functions of the biosphere in the development of the nature of the Earth and maintenance in it
dynamic development.
114. Class arachnids. General characteristics and classification of the class. Structure, development cycles, control measures and prevention.
115. Type protozoa. Characteristic features of the organization, significance for medicine. General characteristics of the type system.
116. Human phylogeny: evolution of primates, australopithecines, archanthropes, paleontropes, non-anthropes. Factors of anthropogenesis. The role of labor in human evolution.
117. Wednesday. As a complex complex of abiotic, biotic and anthropogenic factors.
119. Class sporozoans. Morphofunctional characteristics, development cycles, ways of infection, pathogenic action, diagnosis and prevention.
120. Class arachnids. Ixodid ticks are carriers of human pathogens.
121. Biosphere as a global ecosystem of the Earth. IN AND. Vernadsky is the founder of the doctrine of the biosphere. Modern concepts of the biosphere: biochemical, biogeocenotic, thermodynamic, geophysical, socio-economic, cybernetic.
122. The concept of races and species unity of mankind. Modern (molecular-genetic) classification and distribution of human races.
123. Organization of the biosphere: living, bone, biogenic, bio-bone substance. Living substance.
124. Class insects. General characteristics and classification of detachments of epidemiological significance.
125. Phylogeny of the organs of the digestive system.
126. Influence of environmental factors on the state of human organs, tissues and systems. The importance of environmental factors in the development of defects in the human body.
127. Type flatworms, characteristics, features of organization. medical significance. Type classification.
128. Biogeocenosis, structural elementary unit of the biosphere and elementary unit of the biogeochemical cycle of the Earth.
129. The concept of helminths. Bio- and geohelminths. Biohelminths with migration, without migration.
130. Mankind, as an active element of the biosphere, is an independent geological force. The noosphere is the highest stage in the evolution of the biosphere. Biotechnosphere.
131.Social essence and biological heritage of man. The position of the species Homo sapiens in the system of the animal world.
132. Evolution of the biosphere. Cosmoplanetary conditions for the emergence of life on Earth.
133.Methods for obtaining metaphase chromosomes. Nomenclature of human chromosomes. Specificity and possibilities of methods of human genetics.
134. Type flatworms, characteristics, features, classification of type.
135. Type roundworms. Characteristics, features of the organization and medical significance. Type classification. main representatives. Morphology, development cycles, ways of penetration into the body, pathogenic action, diagnostics and prevention.
136. Man, as a natural result of the process of historical development of the organic world.
5.9. References (main and additional)
Main literature
1.Biology / Ed. V.N. Yarygin. - M, Higher School. 2004. -T. 1.2.
2.Gilbert S. Biology of development. - M.: Mir, 1993. - V.1; 1994. - V.2.
3.Dubinin N.P. General genetics. - M.: Nauka, 1976.
4.Kemp P. Arms K. Introduction to biology. – M.: Mir, 1988.
6.Pekhov A.P. Biology and general genetics. - M.: Ed. Peoples' Friendship University of Russia, 1993.
7. Pekhov A.P. Biology with the basics of ecology.-St.-P.-M.-Krasnodar, 2005.
8.Ricklefs R. Fundamentals of general ecology. - M.: Mir, 1979.
9.Roginsky Ya.Ya., Levin M.G. Anthropology. - M.: Higher school, 1978.
10. Slyusarev A.A., Zhukova S.V. Biology. -K .: Vishcha school. Head publishing house, 1987., 415s.
11.Taylor Miller. Life in the environment. - Progress, Pangea, 1993.-4.1; 1994.-4.2.
12.Fedorov V.D. Gilmanov T.G. Ecology. - M.: MGU, 1980.
14.Shilov I.A. Ecology. - M .: Higher school, 1998.
15.Schwartz S.S. Ecological patterns of evolution. - M.: Nauka, 1980.
16.Yablokov A.V. and Yusufov A.G. evolutionary doctrine. - M.: Higher school, 1989.
17. Yarygin V.N. and etc. Biology. / - M.: Vyssh.shk., 2006.-453p.
additional literature
1..Albert B., Bray D., Lewis J., Raff M, Roberts C., Watson J. Molecular biology of the cell. - M.: Mir, 1994. - T.1,2,3.
2.Belyakov Yu.A. Dental manifestations of hereditary diseases and syndromes. - M.: Medicine, 1993.
3.Bochkov N.P. Clinical genetics. - M.: Medicine, 1993.
4.Dzuev R.I. Study of the karyotype of mammals. - Nalchik, 1997.
5.Dzuev R.I. Chromosomal set of Caucasian mammals. - Nalchik: Elbrus, 1998.
6.Kozlova S.I., Semanova E.E., Demikova N.N., Blinnikova O.E. Hereditary syndromes and medical genetic counseling. -2nd ed. - M.: Practice, 1996.
7. Prokhorov B.B. Human Ecology: Proc. for high school students textbook institutions / - M.: Publishing Center "Academy", 2003.-320s.
8. Kharitonov V.M., Ozhigova A.P. and others. Anthropology: Textbook. For stud. higher Textbook Institutions.-M.: Humanit. Ed. Center VLADOS, 2003.-272p.
5.10. Protocol for the coordination of the RUPD with other disciplines of the direction (specialty)
PROTOCOL OF COORDINATION OF THE WORK PROGRAM WITH OTHER DISCIPLINES OF THE SPECIALTY
The name of the discipline, the study of which is based on this discipline | department | Proposals for changes in the proportions of the material, the order of presentation and the content of the lessons | Decision taken (protocol No., date) by the department that developed the program |
Histology, cytology and embryology | Normal and pathological anatomy | The Department of General Biology, when giving a course of lectures and conducting laboratory classes in General Biology at the 1st year of the Faculty of Medicine (General Medicine and Dentistry), excludes the following sections of lecture material: “Cytology” and “Embryology” (especially when presenting research methods, cell surface and microenvironment , cytoplasm, types of mammalian placenta, germ layers, their significance and differentiation, the concept of embryonic histogenesis). | No. 4 dated 10.02.09. |
5.11. Additions and changes to the RUPD for the next academic year
ADDITIONS AND CHANGES TO THE WORK PROGRAM
FOR 200__ /200__ ACADEMIC YEAR
The following changes have been made to the work program:
Developer:
Position _______________ Acting Surname
(signature)
The work program was reviewed and approved at a meeting of the department
"______" ________________ 200___
Protocol No. ____
Head Department _______________ Dzuev R.I.
(signature)
The changes I approve:
"____" _________________ 200___
Dean of the Charity Fund ____________________ Paritov A.Yu.
(signature)
Dean of the Ministry of Finance ____________________ Zakhokhov R.R.
6. Educational– methodological support of the discipline biology with ecology
One of the most important tasks facing higher education is the training of highly qualified specialists in such areas of social society, where biological science serves as the theoretical basis for practical activities. This has a special place in personnel training.
In recent years, in order to improve the biological training of medical specialists, in accordance with the State Educational Standard (1999), the discipline "Biology" has been introduced in universities for all medical specialties.
The implementation of this urgent task largely depends on the ability of the teacher to select material for classes. Choose the form of its presentation, methods and types of work, the compositional structure of classes and their stages, establishing links between them. Build a system of training, testing and other types of work, subordinating them to the goals set.
The main task of studying at a university is to equip students with the knowledge of the basics of the science of life and, on the basis of the laws and systems of its organization - from molecular genetic to biospheric, to maximally contribute to the biological, genetic and environmental education of students, the development of their worldview, thinking. Various forms of control are offered to test knowledge and skills. The most effective form of control is computer testing for individual blocks of the material covered. It allows you to significantly increase the amount of controlled material in comparison with traditional written control work and thereby creates the prerequisites for increasing the information content and objectivity of learning outcomes.
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Educational and methodological complex on the discipline "state regulation of the economy"
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Educational and methodological complex in the discipline of general professional training "theory and methods of teaching biology" specialty "050102 65 - biology"
Training and metodology complexeducational-methodicalcomplexBydiscipline general professional training "Theory and methods of teaching ... students' works By biology with microscope and micropreparations. Analysis educational-methodicalcomplex For example complexBy section "Plants" ...
The interphase chromosome is an untwisted double strand of DNA; in this state, the information necessary for the life of the cell is read from it. That is, the function of interphase XP is the transfer of information from the genome, the sequence of nucleotides in the DNA molecule, for the synthesis of the necessary proteins, enzymes, etc.
When the time comes for cell division, it is necessary to save all available information and transfer it to daughter cells. XP can't do this in a "disrupted" state. Therefore, the chromosome has to be structured - to twist the thread of its DNA into a compact structure. DNA by this time has already been doubled and each strand is twisted into its own chromatid. 2 chromatids form a chromosome. In prophase, under a microscope, small loose lumps become visible in the cell nucleus - these are future XP. They gradually become larger and form visible chromosomes, which by the middle of the metaphase line up along the equator of the cell. Normally, in telophase, an equal number of chromosomes begin to move towards the poles of the cell. (I do not repeat the 1st answer, everything is correct there. Summarize the information).
However, it sometimes happens that chromatids cling to each other, intertwine, pieces come off - and as a result, two daughter cells receive slightly unequal information. This thing is called pathological mitosis. After it, the daughter cells will not work correctly. With severe damage to the chromosomes, the cell will die, with a weaker one, it will not be able to divide again or give a series of incorrect divisions. Such things lead to the emergence of diseases, from violations of the biochemical reaction in a single cell, to cancer of some organ. Cells divide in all organs, but with different intensity, so different organs have a different probability of getting cancer. Fortunately, such pathological mitoses do not happen too often, and nature has come up with mechanisms for getting rid of the resulting abnormal cells. Only when the organism's environment is very bad (radioactive background is increased, severe water and air pollution with harmful chemicals, uncontrolled use of drugs, etc.) does the natural defense mechanism fail. In this case, the likelihood of diseases increases. It is necessary to try to reduce the harmful factors affecting the body to a minimum and take bioprotectors in the form of live food, fresh air, vitamins and substances necessary in the area, it can be iodine, selenium, magnesium or something else. Don't ignore your health concerns.
Chromatin(Greek χρώματα - colors, paints) - this is the substance of chromosomes - a complex of DNA, RNA and proteins. Chromatin is located inside the nucleus of eukaryotic cells and is part of the nucleoid in prokaryotes. It is in the composition of chromatin that the realization of genetic information, as well as DNA replication and repair takes place.
There are two types of chromatin:
1) euchromatin, localized closer to the center of the nucleus, lighter, more despirilized, less compact, more functionally active. It is assumed that it contains the DNA that is genetically active in the interphase. Euchromatin corresponds to chromosome segments that are despiralized and open for transcription. These segments are not stained and are not visible under a light microscope.
2) heterochromatin - a densely spiralized part of chromatin. Heterochromatin corresponds to condensed, tightly coiled chromosome segments (making them inaccessible to transcription). It is intensely stained with basic dyes, and in a light microscope has the appearance of dark spots, granules. Heterochromatin is located closer to the shell of the nucleus, is more compact than euchromatin and contains "silent" genes, i.e. genes that are currently inactive. Distinguish between constitutive and facultative heterochromatin. Constitutive heterochromatin never becomes euchromatin and is heterochromatin in all cell types. Facultative heterochromatin can be converted into euchomatin in some cells or at different stages of the organism's ontogeny. An example of an accumulation of facultative heterochromatin is the Barr body, an inactivated X chromosome in female mammals, which is tightly twisted and inactive in the interphase. In most cells, it lies near the karyolemma.
Sex chromatin - special chromatin bodies of the cell nuclei of female individuals in humans and other mammals. They are located near the nuclear membrane, on the preparations they usually have a triangular or oval shape; size 0.7-1.2 microns (Fig. 1). Sex chromatin is formed by one of the X-chromosomes of the female karyotype and can be detected in any human tissue (in cells of mucous membranes, skin, blood, biopsied tissue). The simplest study of sex chromatin is to study it in epithelial cells of the oral mucosa. A buccal mucosal scraping taken with a spatula is placed on a glass slide, stained with acetoorcein, and 100 light-stained cell nuclei are analyzed under a microscope, counting how many of them contain sex chromatin. Normally, it occurs on average in 30-40% of the nuclei in women and is not found in men.
15.Features of the structure of metaphase chromosomes. Types of chromosomes. chromosome set. Chromosome rules.
metaphasic chromosome consists of two sister chromatids connected by a centromere, each of which contains one DNP molecule, stacked in the form of a supercoil. During spiralization, the sections of eu- and heterochromatin stack in a regular way, so that alternating transverse bands are formed along the chromatids. They are identified with the help of special colors. The surface of chromosomes is covered with various molecules, mainly ribonucleoproteins (RNPs). Somatic cells have two copies of each chromosome, they are called homologous. They are the same in length, shape, structure, arrangement of stripes, they carry the same genes that are localized in the same way. Homologous chromosomes can differ in the alleles of the genes they contain. A gene is a section of a DNA molecule on which an active RNA molecule is synthesized. The genes that make up human chromosomes can contain up to two million base pairs.
Despiralized active regions of chromosomes are not visible under a microscope. Only a weak homogeneous basophilia of the nucleoplasm indicates the presence of DNA; they can also be detected by histochemical methods. Such areas are referred to as euchromatin. Inactive highly helical complexes of DNA and high molecular weight proteins stand out when stained in the form of clumps of heterochromatin. Chromosomes are fixed on the inner surface of the karyotheca to the nuclear lamina.
Chromosomes in a functioning cell provide the synthesis of RNA necessary for the subsequent synthesis of proteins. In this case, the reading of genetic information is carried out - its transcription. Not the entire chromosome is directly involved in it.
Different parts of the chromosomes provide the synthesis of different RNA. Particularly distinguished are the sites synthesizing ribosomal RNA (rRNA); not all chromosomes have them. These sites are called nucleolar organizers. The nucleolar organizers form loops. The tops of the loops of different chromosomes gravitate towards each other and meet together. Thus, the structure of the nucleus, called the nucleolus, is formed (Fig. 20). Three components are distinguished in it: a weakly stained component corresponds to chromosome loops, a fibrillar component corresponds to transcribed rRNA, and a globular component corresponds to ribosome precursors.
Chromosomes are the leading components of the cell that regulate all metabolic processes: any metabolic reactions are possible only with the participation of enzymes, while enzymes are always proteins, proteins are synthesized only with the participation of RNA.
At the same time, chromosomes are also the guardians of the hereditary properties of the organism. It is the sequence of nucleotides in DNA chains that determines the genetic code.
The location of the centromere determines three main types of chromosomes:
1) equal shoulder - with shoulders of equal or almost equal length;
2) uneven shoulders, having shoulders of unequal length;
3) rod-shaped - with one long and the second very short, sometimes hardly detectable shoulder. chromosome set-Karyotype - a set of features of a complete set of chromosomes inherent in the cells of a given biological species, given organism or cell line. A karyotype is sometimes also called a visual representation of a complete chromosome set. The term "karyotype" was introduced in 1924 by a Soviet cytologist
Chromosome Rules
1. The constancy of the number of chromosomes.
The somatic cells of the body of each species have a strictly defined number of chromosomes (in humans -46, in cats - 38, in Drosophila flies - 8, in dogs -78, in chickens -78).
2. Pairing of chromosomes.
Each. the chromosome in somatic cells with a diploid set has the same homologous (same) chromosome, identical in size, shape, but unequal in origin: one from the father, the other from the mother.
3. The rule of individuality of chromosomes.
Each pair of chromosomes differs from the other pair in size, shape, alternation of light and dark stripes.
4. The rule of continuity.
Before cell division, the DNA is doubled and the result is 2 sister chromatids. After division, one chromatid enters the daughter cells, so the chromosomes are continuous: a chromosome is formed from a chromosome.
16.Human karyotype. His definition. Kariogram, the principle of compilation. Idiogram, its content.
Karyotype.(from karyo ... and Greek typos - imprint, shape), a set of morphological characteristics of chromosomes typical of the species (size, shape, structural details, number, etc.). An important genetic characteristic of a species that underlies karyosystematics. To determine the karyotype, a micrograph or a sketch of chromosomes is used during microscopy of dividing cells. Each person has 46 chromosomes, two of which are sex. In a woman, these are two X chromosomes (karyotype: 46, XX), and in men, one X chromosome and the other is Y (karyotype: 46, XY). The study of the karyotype is carried out using a method called cytogenetics.
Idiogram(from the Greek idios - one's own, peculiar and ... gram), a schematic representation of the haploid set of chromosomes of an organism, which are arranged in a row according to their size.
Kariogram(from karyo... and... gram), a graphic representation of the karyotype to quantify each chromosome. One of the types of K. is an idiogram, a schematic sketch of chromosomes arranged in a row along their length (Fig.). Dr. type K. - a graph on which the coordinates are any values \u200b\u200bof the length of a chromosome or its part and the entire karyotype (for example, the relative length of chromosomes) and the so-called centromeric index, that is, the ratio of the length of the short arm to the length of the entire chromosome. The arrangement of each point on K. reflects distribution of chromosomes in a karyotype. The main task of karyogram analysis is to identify the heterogeneity (differences) of outwardly similar chromosomes in one or another of their groups.
