TYPE CRITERIA
Tasks : to study the concept of species, its criteria and structure.
Content elements: species, species criteria: morphological, physiological, genetic, ecological, geographical, historical.
Lesson type: combined.
Equipment: images of several organisms belonging to the same species.
During the classes
I. Organizing time.
II. Checking students' knowledge.
Test on the topic "Selection"
Questions:
1. A plant population characterized by a similar genotype and phenotype, obtained as a result of artificial selection, is:
a) view;
b) subspecies;
c) breed;
d) variety.
2. How is the breeding of new varieties carried out in plant breeding?
a) Growing plants on fertilized soils;
b) vegetative propagation using layering;
c) crossing plants of different varieties and subsequent selection of offspring with valuable traits;
d) growing plants on poor soils.
3. With artificial selection, signs are formed that are useful:
a) a person;
b) mind;
c) biogeocenosis;
d) breed.
4. The method of obtaining new varieties of plants by exposing the body to ultraviolet or X-rays is called:
a) heterosis;
b) polyploidy;
c) mutagenesis;
d) hybridization.
5. The phenomenon of heterosis is associated with:
a) with a new combination of genes;
b) with gene variability;
c) with modification variability;
d) with chromosomal rearrangements.
6. The group of animals most similar in structure and life activity, created for agricultural purposes by man, is called:
a) variety;
b) view;
c) breed;
d) kind.
7. A pure line of plants is the offspring of:
a) heterozygous forms;
b) one self-pollinating individual;
c) intervarietal hybrid;
d) two heterozygous individuals.
8. What underlies the creation of new breeds of farm animals?
a) Crossing and artificial selection;
b) natural selection;
c) good care of animals, their diet;
d) struggle for existence.
9. N. I. Vavilov developed:
a) the chromosome theory of heredity;
b) evolutionary theory;
c) the hypothesis of the origin of life;
d) the doctrine of the centers of diversity and origin of cultivated plants.
10. Inbreeding in animal breeding is used for:
a) fixing desirable features;
b) improvement of signs;
c) increase in heterozygous forms;
d) selection of the most productive animals.
Answers: 1 – d, 2 – c, 3 – a, 4 – c, 5 – a, 6 – c, 7 – b, 8 – a, 9 – d, 10 – a.
III. Learning new material.
The species is the basic structural unit of living nature. It arises, develops, and when the conditions of existence change, it can disappear or be transformed into other species.
View – a set of individuals occupying a certain area of \u200b\u200bdistribution, similar in structure, freely interbreeding with each other and giving fertile offspring
To date, about 1.5 million animal species and more than half a million plant species have been described. The process of describing new species continues. Every year, up to a thousand new species of living organisms are described. Some species differ from others by a number of features, the totality of which constitutes the criteria for the species.
View criteria - a set of certain features that make it possible to characterize any group of organisms as a species.
View criteria
Content of the criterion
1. Morphological
The similarity of the external and internal structure of individuals of the same species, structural features of representatives of the same species
2. Physiological
The similarity of all life processes, and above all the process of reproduction (free crossing of individuals of the species)
3. Genetic
Each species is characterized by a certain set of chromosomes inherent only to it and their special
structure (size, shape, composition of DNA)
4. Ecological
A species occupies a certain place in nature, has its own specialization, a set of environmental factors necessary for its existence
5. Geographic
The species has a certain area of \u200b\u200bdistribution in nature - an area
6. Historical
Common ancestors, a single history of origin
and development of the species
All criteria taken separately are relative. For example, different species may have morphological similarities (sibling species), but they do not interbreed (for example, six sibling species in the malarial mosquito). Therefore, to establish whether a group of organisms is a species, it is not enough to use any one criterion; only their combined study can give a correct answer to this question.
view structure
IV. Consolidation of the studied material.
Conversation on:
1. What is a view?
2. What kind of criteria do you know?
3. Is it possible to establish the belonging of an organism to a particular species by one criterion?
4. Why is it necessary to use together all the criteria to establish species?
5. How many species live on our planet?
Homework: § 4.1.
The definition of the concept of "kind" is very difficult.
We will consider a species as a historically formed set of organisms occupying a certain habitat and characterized by a common origin, a similar system of adaptations to environmental levels, and reproduction in generations of the main adaptive features and traits.
Organisms of one species have a phenotype and genotype characteristic of that species, different from those of organisms of another species.
The species occupies a certain area. The distribution range of some species is wide, and such species are usually polytypic - they include several geographical races, or subspecies. Other species have a much more limited range, they usually do not form geographical races and are monotypic. The individuals that make up the species do not form an unchanging homogeneous mass. Each organism of a species, having common and characteristic features, also has its own individual genotypic features, which together represent the hereditary variability of the species, or, as is sometimes called, the "gene pool" of the species.
The species, representing a single set of organisms, is divided into separate populations. population called a set of freely interbreeding individuals of the same species, characterized by a common habitat and adaptation to given conditions of existence. The population is formed under the influence of the condition of existence on the basis of the interaction of factors of heredity, variability, and selection. The formation of populations is a peculiar way of "fitting" a species to the specific conditions of its existence. Animal breeds and plant varieties created by artificial selection are also represented by separate populations.
The processes of population formation and their dynamics constitute microevolution. The emergence of new species begins with divergence - the division of a species into separate, non-crossing or isolated groups of organisms. The population is a kind of "forge" in which natural selection creates new forms.
In nature, populations of each species are characterized by genetic diversity. But we often don't notice it. Individuals of a population and a species appear to us relatively uniform in outward appearance. This relative uniformity of animals and plants, which allows taxonomists to attribute animals and plants to certain species, subspecies, races, is created by natural selection. Selection ensures not only diversity but also uniformity within a species.
However, this uniformity refers only to the main typical features, signs and properties of the organisms of a given population. As soon as we begin to genetically analyze the composition of the population in detail, decomposing it into separate lineages, we will immediately discover enormous genotypic variability. At the same time, it turns out that each population, within which individuals have interbred with each other for a long time, has its own character of variability in a limited area under given climatic conditions.
Sources of hereditary variability in a population are mutational and combinative variability. The action of genetic laws in a population is the subject of study of population genetics.
In nature, there are no two organisms that are absolutely similar to each other in terms of genotype. Zoologists or botanists who study biological processes in any group of individuals always deal with a hereditarily heterogeneous group of organisms. But since they study the phenotype of organisms, they have the right to neglect the genetic diversity of their material.
The study of the population can be carried out by a purely descriptive method. In this case, the phenotypic characteristics of the forms of the population, its biological characteristics are determined, the conditions of existence and the relationship of organisms, food chains, competition, population dynamics over the years and its dependence on various factors are clarified. Populations are isolated and formed as a result of the action of many factors: the method of reproduction, the nature of variability, changes in the number of individuals, the rate and direction of selection, climatic, geographical and physiological isolation. The main one is the selection of traits that ensure the process of reproduction of generations, i.e. reproduction. Obviously, with different methods of reproduction, the emergence and maintenance of populations is carried out in different ways, as can be seen by comparing the populations of cross-fertilizing (allogamous) and self-fertilizing (autogamous) organisms.
For the existence of a population, various types of hereditary variability are of paramount importance: gene mutations, chromosomal rearrangements, and polyploidy. Non-hereditary changes can play only a limited role. Organisms that differ genotypically, for example, in one gene, may not differ morphologically from each other, but have different physiological characteristics (viability, duration of development, fecundity). Genetic methods make it possible to form a more complete picture of the hereditary potential of a population, its adaptive characteristics, and the direction of evolution.
Breeders must be recognized as the initiators of the study of genetics, because in order to reveal the diversity of genotypes in populations, it was necessary to isolate, select for crossing individual pairs of parents and then study their offspring in a number of generations. This is exactly what breeders did when they created various varieties and breeds. However, the scientific foundations for the genetic study of a population could only be laid after the discovery of G. Mendel, who established the quantitative patterns of inheritance.
The first scientific study of the population, which combined genetic and statistical methods, was undertaken by the Danish plant physiologist and geneticist W. Johannsen. His classic work On Inheritance in Populations and Pure Lines, published in 1903, marked the beginning of the genetic study of populations. As often happens in science, a classical discovery is made on a seemingly elementary phenomenon and using a simple technique. So in this case, W. Johannsen chose as the object of study populations not cross-pollinated, but self-pollinated plants - barley, beans and peas. Methodically, this simplified the work, since each such population could be easily decomposed into groups of descendants of individual individuals, i.e., separate, “pure” lines could be distinguished. “A pure line,” he wrote, “I call individuals who are descended from one self-pollinating individual. From this it is clear that the population of absolute self-pollinators consists only of pure lines, whose individuals in nature can be mixed, but cannot be affected by crossing.
The weight and size of the seeds were taken as signs. These quantitative traits are determined by the action of many genes, that is, they are determined polygenically, and are highly susceptible to variability under the influence of environmental factors - soil composition, climate, planting method, etc. Therefore, to establish the nature of their inheritance, it is necessary to use mathematical methods variability analysis.
According to these features, there is a pronounced modification, or paratypic, variability. There were different points of view on the significance of this variability for evolution in biology. Proponents of the theory of inheritance of acquired properties believed that changes caused by the influence of environmental factors are inherited, transmitted to offspring. Opponents of this theory denied the inheritance of modification changes. The solution of this dispute in favor of the latter was of fundamental importance, since the selection of organisms by phenotype without revealing hereditary potencies had previously been widespread in breeding and hindered the breeding of animal breeds and plant varieties.
Johannsen weighed the seeds of one bean variety and built a variation series according to this indicator. The weight of the seeds turned out to be variable in the range from 150 to 750 mg. Subsequently, seeds weighing from 250 to 350 mg were sown separately from seeds weighing 550-650 mg. Seeds were again weighed from each grown plant. Since the bean is a self-pollinating plant, the genotype of seeds from one plant must be the same, and seeds from different plants may have genotypic differences. Therefore, heavy seeds (550-650 mg) and light seeds (250-350 mg) selected from the variety representative of the population produced plants whose seeds varied significantly in weight. The average weight of seeds on plants grown from heavy seeds was 518.7 mg, and on plants grown from light seeds - 443.4 mg. This showed that the bean variety-population consists of genetically different plants, each of which can become the ancestor of a pure line.
Over the course of 6-7 generations, Johannsen also selected heavy and light seeds from each plant separately, i.e., he selected within pure lines. With such selection, no line has shifted in the series of generations towards heavy or light seeds. Consequently, the variability in seed weight within the pure line was non-hereditary, modification.
As a result of his research, Johannsen came to the following conclusions: 1) “selection in a population causes ... a greater or lesser shift - in the direction of selection - of that average trait around which, fluctuating, the corresponding individuals vary” and 2) “within pure lines, regression (degree the similarity of the trait of the offspring with the maternal one) was ... complete; selection within pure lines did not cause any type shift.”
As we can see, the population of autogamous plants consists of genotypically heterogeneous lines. Plants of such a population do not interbreed and do not exchange hereditary information. In this case, the existence of a population is based on strict natural selection of lines of a certain genotype, on the commonality of adaptive mechanisms to the same type of environmental conditions. In other words, the change in the population of autogamous plants and animals is carried out by the selection of certain hereditarily different lines and clones that have adaptive advantages.
With self-fertilization, an individual organism can be the initiator of a new race, subspecies and species, as well as a variety or breed. For example, a new variety of wheat may be bred from a single grain selected from a population.
However, speaking of high homozygosity in pure lines, it should be borne in mind that even pure lines cannot be absolutely homozygous for the following reasons. First, there are no obligate (absolute) self-pollinating plants. In populations of self-pollinators, for example, wheat, tomatoes, etc., plants with open flowering and cross-pollination are always found with one frequency or another. Because of this, between pure lines in populations, although rarely, the processes of crossing and, accordingly, the exchange of hereditary information take place. Secondly, self-pollinating plants have mutations that prevent self-pollination (incompatibility). Thirdly, in pure lines of self-pollinators, even in one generation, a very tangible number of various mutations arise that violate the homogeneity of the pure line.
Due to these reasons, varieties of self-pollinating plants, when reproduced in production, may lose some of their varietal qualities and require constant monitoring, on which the need for variety renewal is based.
During vegetative propagation of agam organisms that do not have a sexual process or have lost it again (some protozoa, fungi, algae, etc.), individual clones are the object of selection in the population. The genetic integrity (integration) of such clones in a population is very low due to the impossibility of crossing between individuals of different clones, but such populations, apparently, still exist in nature and are maintained by selection based on symbiotic relationships of different genotypes.
In cross-fertilizing organisms in nature, the population is formed on the basis of free crossing of heterosexual individuals with different genotypes, i.e., on the basis of panmixia. At the same time, the hereditary structure of the next generation is reproduced on the basis of various combinations of different gametes during fertilization. This implies that the number of individuals of a particular genotype in each generation will be determined by the frequency of occurrence of different gametes produced by genotypically different parental organisms. This means that traits and properties are preserved and distributed in the population based on the patterns of changes in the frequency of gene distribution. Such changes are based on the patterns of inheritance discovered by G. Mendel and T. Morgan. Knowing this made it possible to derive rules for the distribution of genes in a panmictic population.
Obviously, those organisms whose genotypes provide the best adaptation to the conditions of existence will produce a greater number of corresponding gametes than less adapted ones. Consequently, the frequency (occurrence) of a particular gene in a population will also be determined by natural selection.
The community of freely interbreeding genotypically different organisms within a species is called by some geneticists the Mendelian population. We prefer to call it panmictic, since its existence is determined not only by the laws of Mendel, but also by the interaction of all evolutionary factors that ensure the freedom of interbreeding of organisms within a population. The genotype diversity of a panmictic population is the result of mutational and combinative variability. A newly emerging mutation, in order to become the property of a population, must be preserved and reproduced, i.e., be part of the genotypes of a number of organisms. Any mutation in a population has its own fate.
Due to the spread of a large number of various mutations in the population, the genotypes of organisms are saturated with various mutations, which are most often in a heterozygous state. For example, the number of plants heterozygous for certain mutations can be quite a high percentage in a population. As the concentration of mutations in the population increases, they become homozygous.
The enormous saturation of a population with mutant genes is characteristic not only of cultivated plants and domestic animals, but, as S. S. Chetverikov was the first to show, also of natural populations. At the same time, mutations occur in the population that differ both in their genetic nature (gene mutations and chromosomal rearrangements) and in their phenotypic manifestation.
To illustrate the division of a panmictic population under the influence of selection, let us consider a model experiment with an artificially created hybrid population set up by the American geneticists D. Jones and E. East. These two researchers crossed two varieties of tobacco that differed in the length of the rim (short and long). Plants of the first generation were crossed with each other, and two lines A and B were taken from the second generation with similar variability in this trait.
The corolla length is determined by many genes, and therefore in F 2 it ranged from 52 to 88 mm in these lines. Subsequently, selection was made in the offspring of the taken lines for three generations: in line A - for a short corolla, and in line B - on a long whisk. In each generation, selected forms were crossed within both lines: in line A - with a short rim, and in line B - with a long rim. As we can see, already in the fifth generation, lines A and B differed so much that there was no overlap (transgression) between them, i.e., the maximum length of the corolla in line A was less than the minimum length in line B.
Consequently, by selecting and crossing the selected forms, it is possible to create lines with a different expression of the trait than in the original population: selection divides the population into different genotypes. In this experiment, artificial selection was carried out for one trait with deliberate crossing of plants. In nature, natural selection is carried out according to many characteristics and either preserves and maintains the population in an integral state, or decomposes it according to the specific conditions of existence.
The study of the genetics of populations is carried out by various methods, the main of which are cytogenetic, ecological-physiological, and mathematical.
The first two methods are used in the analysis of inheritance in a population - to estimate the concentration of mutations and frequencies, mutations. The ecological-physiological method turns out to be necessary for assessing the action of abiotic and biotic factors in determining the adaptive value of phenotypes belonging to genetically different classes of individuals. At the same time, modeling the action of selection in artificially created synthetic populations with predetermined genetic parameters opens up great experimental possibilities - the introduction of certain mutations, inversions, translocations, etc. into the population.
The mathematical method makes it possible to give a rigorous quantitative description of biological processes. The use of electronic computers was especially promising for modeling the dynamics of the genetic structure of a population, taking into account the complex interaction of many factors. The situations described in this case come close to reflecting the true, complex and contradictory picture of evolutionary processes occurring in natural populations of plants and animals.
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1. Increasing the productivity of molds that produce antibiotics is achieved by
1. Polyploidization
2. Mass selection
3. Artificial mutagenesis
4. Intraspecific hybridization
Explanation: In mushrooms, as well as in bacteria, genes for the production of antibiotics are built in, as a result of which they produce antibiotics in large quantities. The correct answer is 3.
2. In cell engineering, research is carried out related to
Explanation: cell engineering (rather than genetic) deals with nuclear transplantation. The correct answer is 1.
3. Hybrids obtained by distant hybridization are sterile, since they have
1. The process of conjugation in meiosis is impossible
2. The process of mitotic division is disrupted
3. Recessive mutations appear
4. Lethal mutations dominate
Explanation: when crossing non-closely related hybrids, there are no such problems as when crossing closely related individuals, therefore their offspring do not appear, since conjugation does not occur in meiosis. The correct answer is 1.
4. An increase in the number of chromosomes, a multiple of the haploid set, is obtained in plant breeding by
1. Heterosis
3. Artificial selection
4. Artificial mutagenesis
Explanation: we are talking about obtaining polyploid organisms, that is, with an increased set of chromosomes. Such a set can only be obtained by artificial mutagenesis. The correct answer is 4.
5. What makes it possible to overcome the infertility of offspring obtained by distant hybridization of plants?
2. Obtaining polyploids
3. Analyzing cross
4. Mass selection
Explanation: distant hybridization is possible only when obtaining polyploids. The correct answer is 2.
6. In breeding to obtain new polyploid plant varieties
2. Cross clean lines
Explanation: polyploids - organisms with a multiply increased set of chromosomes: 4n, 6n, 8n, etc. The correct answer is 1.
7. Individual selection in breeding, unlike mass selection, is more effective, since it is carried out
1. By genotype
2. Under the influence of environmental factors
3. Influenced by human activity
4. By phenotype
Explanation: mass selection is based on the phenotype (we select individuals with the well-defined trait we need), and individual selection is based on the genotype (that is, it is among individuals with a known genotype). The correct answer is 1.
8. To overcome the infertility of interspecific hybrids, G.D. Karpechenko proposed a method
1. Polyploidy
2. Experimental mutagenesis
3. Distant hybridization
4. Inbreeding
Explanation: polyploidy is a multiple increase in the set of chromosomes, which allows individuals of different species to produce offspring, which is created artificially (but there are also natural polyploids, they are usually larger and stronger than their relatives). The correct answer is 1.
9. The phenomenon of hybrid strength, which manifests itself in an increase in the productivity and viability of organisms, is called
1. Polyploidy
2. Mutagenesis
3. Heterosis
4. Dominance
Explanation: heterosis - a phenomenon in which, during interspecific crossing, heterozygous organisms are obtained. These organisms have very strong heterozygous traits. That is, in this case, the heterozygote is more pronounced than the homozygote for the dominant trait. For example, they may be more productive and viable. The correct answer is 3.
10. Animal breeding uses the method
1. Obtaining polyploids
2. Mentor (educator)
3. Self-fertilization of individuals
4. Estimates of parent individuals by offspring
Explanation: The purpose of breeding is to develop a new variety or breed with traits that are useful to humans and with greater manifestation. Such breeding takes a lot of time, since the ultimate goal is to obtain a pure line of individuals with the greatest manifestation of a trait, but at the beginning of this path, when crossing parental individuals, breeders cannot find out what traits the parents contain, they can only find out when breeding offspring, and maybe even several generations of offspring of these parents. The correct answer is 4.
11. N.I. Vavilov, while studying the characteristics of the inheritance of traits of cultivated plants, substantiated the law
1. Homologous series in hereditary variability
2. Independent inheritance of non-allelic genes
3. Dominance of first generation hybrids
4. Sex-linked inheritance
Explanation: N.I. Vavilov formulated the law of homological series, which is as follows: due to the great similarity of their genotypes (almost identical sets of genes), closely related species have similar potential hereditary variability (similar mutations of identical genes); as the evolutionary-phylogenetic removal of the studied groups (taxa), due to the emerging genotypic differences, the parallelism of hereditary variability becomes less complete. Consequently, the basis of parallelisms in hereditary variability are mutations of homologous genes and genotype regions in representatives of different taxa, that is, truly homologous hereditary variability. However, even within the same species, outwardly similar characters can be caused by mutations in different genes; such phenotypic parallel mutations of various genes can, of course, also occur in different, but rather closely related, species. The correct answer is 1.
12. Inbreeding in animal breeding is used for
1. Feature improvements
2. Increases in heterotic forms
3. Obtaining polyploid forms
4. Selection of the most productive animals
Explanation: in breeding, for example, a chicken and a rooster with large muscle mass are crossed in order to get offspring with muscle mass too. The correct answer is 1.
13. The method of distant hybridization of individuals is used by breeders for
1. Increasing the fertility of individuals
2. Shaping clean lines
3. Appearance of mutant forms
Explanation: the distant hybridization method is used to obtain the effect of heterosis, since with this effect, heterozygous traits appear much brighter in offspring than in parent individuals (the presence of the effect of heterosis has been proven, but the reasons have not been fully elucidated). The correct answer is 4.
14. What method do scientists use to obtain combinative variability in cultivated plants?
1. Hybridization
2. Tissue culture
3. Vaccinations
4. Selection
Explanation: combinative variability is possible (choosing from the proposed options) only in the case of hybridization, since combinative variability is the variability that occurs when parental genes are recombined. The reasons may be violations in: crossing over in the metaphase of meiosis, divergence of chromosomes in meiosis, fusion of germ cells. The correct answer is 1.
15. In breeding, to overcome the infertility of distant hybrids, they use
1. Polyploid organisms
2. Purebred individuals
3. Heterozygous organisms
4. Individuals of the same sex
Explanation: interspecific crossing of polyploid organisms is possible, and the infertility of distant hybrids is overcome. The correct answer is 1.
Tasks for independent solution
1. With closely related crossing, the viability of the offspring decreases due to
1. Manifestations of recessive mutations
2. Occurrence of dominant mutations
3. Increase in the proportion of heterozygotes
4. Reduction in the number of dominant homozygotes
The correct answer is 1.
2. The effect of heterosis is manifested due to
1. Increase in the proportion of homozygotes
The correct answer is 4.
3. At the heart of the creation of pure lines of cultivated plants by breeders is the process
1. Reducing the proportion of homozygotes in the offspring
2. Reducing the proportion of polyploids in the offspring
3. Increase in the proportion of heterozygotes in the offspring
4. Increasing the proportion of homozygotes in the offspring
The correct answer is 4.
4. Obtaining hybrids based on the connection of chromosomes of cells of different organisms is engaged in
1. Cell engineering
2. Microbiology
3. Genetic engineering
4. Cytology
The correct answer is 1.
5. The phenomenon of hybrid strength, which manifests itself in an increase in the productivity and viability of organisms, is called
1. Polyploidy
2. Mutagenesis
3. Heterosis
4. Dominance
The correct answer is 3.
6. To obtain a high yield of potatoes, it should be hilled several times during the summer for
1. Accelerate fruit ripening
2. Pest reduction
3. Development of adventitious roots and stolons
4. Improving the nutrition of the roots with organic substances
The correct answer is 3.
7. In plant breeding, pure lines are obtained by
1. Cross pollination
2. Self-pollination
3. Experimental mutagenesis
4. Interspecific hybridization
The correct answer is 2.
8. The decrease in the effect of heterosis in subsequent generations is due to
1. Manifestation of dominant mutations
2. An increase in the number of heterozygous individuals
3. An increase in the number of homozygous individuals
4. The appearance of polyploid forms
The correct answer is 3.
9. Obtaining hybrids based on the connection of cells of different organisms using special methods is
1. Cell engineering
2. Microbiology
3. Systematics
4. Physiology
The correct answer is 1.
10. In animal breeding, in contrast to the breeding of plants and microorganisms, selection is carried out
1. Artificial
2. Bulk
3. According to the exterior
4. Stabilizing
The correct answer is 3.
11. What is a variety or breed?
1. Artificial population
2. Natural population
3. View
4. Genus
The correct answer is 1.
12. Animals are practically not used in breeding
1. Mass selection
2. Unrelated crossing
3. Inbreeding
4. Individual selection
The correct answer is 1.
13. Polyploidy is used in breeding
1. Molds
2. Cap mushrooms
3. Pets
4. Cultivated plants
The correct answer is 4.
14. A plant population characterized by a similar genotype and phenotype, obtained as a result of artificial selection, is
1. View
2. Subspecies
3. Breed
4. Variety
The correct answer is 4.
15. Individual selection in plant breeding is carried out to obtain
1. Hybrids
2. Heterosis
3.Clean lines
4. Self-pollinating individuals
The correct answer is 3.
16. In breeding, the phenomenon of heterosis is explained
1. A multiple increase in the number of chromosomes
2. Change in the gene pool of a variety or breed
3. The transition of many genes to a homozygous state
4. Heterozygous hybrids
The correct answer is 4.
17. The basis for the creation of new breeds of farm animals is
1. Crossing and artificial selection
2. Influence of the natural environment on organisms
4. Compliance with the diet and complete feeding
The correct answer is 1.
18. How is the breeding of new varieties carried out in plant breeding?
1. Growing plants on fertilized soils
2. Vegetative propagation using layering
3. Crossing plants of different varieties with subsequent selection
4. Growing plants on poor soils
The correct answer is 3.
19. To restore the ability to reproduce in hybrids with distant hybridization, it is necessary
1. Convert them to polyploid forms
2. Propagate them vegetatively
3. Obtain Heterotic Organisms
4. Draw clean lines
The correct answer is 1.
20. A pure line of plants is an offspring
1. Heterotic forms
2. One self-pollinating individual
3. Intervarietal hybrid
4. Two heterozygous individuals
The correct answer is 2.
21. Artificial mutagenesis is most often used in breeding
1. Microorganisms
2. Pets
3. Cap mushrooms
4. Filamentous algae
The correct answer is 1.
22. Polyploid forms of the silkworm were obtained by
1. Inbreeding
2. Increase in the number of chromosomes in the offspring genotype
3. Drawing clean lines
4. Changes in the nature of nutrition of the offspring
The correct answer is 2.
23. Mass selection in plant breeding is used to
1. Estimates of offspring genotypes
2. Selection of plants by phenotype
3. Obtaining clean lines
4. Getting the effect of heterosis
The correct answer is 2.
24. The ability to predict the occurrence of similar features in related species appeared with the discovery of the law
1. Intermediate inheritance of traits
2. Segregation of traits in offspring
3. Homological series in hereditary variability
4. Linked inheritance of genes
The correct answer is 3.
25. What agricultural method improves the supply of oxygen to the roots of cultivated plants?
1. Thinning crops
2. Top dressing with mineral fertilizers
3. Weeding
4. Loosening the soil
The correct answer is 4.
26. Preservation of traits in heterotic hybrids of plants is possible only with
1. Sexual reproduction
2. Vegetative propagation
3. Distant hybridization
4. Using the polyploidy method
The correct answer is 2.
27. Polyploid plants are obtained in breeding by
1. Artificial mutagenesis
2. Vegetative propagation
3. Crossing heterozygous plants
4. Heterosis
The correct answer is 1.
28. In accordance with the law of homological series N.I. Vavilov, similar series of hereditary variability can be found in
1. Potato and sunflower
2. Strawberries and peas
3. Wheat and barley
4. Apple trees and grapes
The correct answer is 3.
29. Growing tissues outside the body - method
1. Centrifugation
2. Microscopy
3. Cell cultures
4. Polyploidy
The correct answer is 3.
30. A population of microorganisms characterized by similar hereditary characteristics and certain external features, obtained as a result of artificial selection, is
1. Strain
2. Genus
3. View
4. Subspecies
The correct answer is 1.
31. In cell engineering, research is carried out related to
1. Transfer of nuclei from one cell to another
2. Introduction of human genes into bacterial cells
3. Rearrangement of the organism's genotype
4. Transplantation of genes from bacteria into cereal cells
The correct answer is 1.
32. An increase in the number of chromosomes, a multiple of the haploid set, is obtained in plant breeding by
1. Heterosis
2. Inbreeding
3. Artificial selection
4. Artificial mutagenesis
The correct answer is 4.
33. What makes it possible to overcome the infertility of offspring obtained by distant hybridization of plants?
1. Formation of haploid spores
2. Obtaining polyploids
3. Analyzing cross
4. Mass selection
The correct answer is 2.
34. In breeding for obtaining new polyploid plant varieties
1. Multiple increase in the number of chromosomes in cells
2. Cross clean lines
3. They cross parents and offspring
4. Reduce the number of chromosomes in cells
The correct answer is 1.
35. The effect of heterosis is manifested due to
1. Increase in the proportion of homozygotes
2. Emergence of polyploid individuals
3. Increase in the number of mutations in somatic cells
4. Transition of recessive mutations to a heterozygous state
The correct answer is 4.
On this and the next 3 pages of my blog there are test questions of the Open Job Bank FIPI
on the 3rd section of biology "Organism as a biological system".
In total, in this section on the FIPI website, 1002 tasks were first published on 101 pages.
31
.
In addition to plants,
1) saprotrophic fungi
2) decay bacteria
3) chemosynthetic bacteria
4) hat mushrooms
The decrease in the effect of heterosis in subsequent generations is due to
1) manifestation of dominant mutations
2) an increase in the number of heterozygotes
3) a decrease in the number of homozygotes
4) manifestation of recessive mutations
Using the drawing, determine which features of tomato fruits (dark or light color, pear-shaped or spherical shape) dominate; what are the genotypes of the parents, genotypes and phenotypes of F1 and F2 hybrids. Make a scheme for solving the problem. The genes for both traits are not linked.
An organism with a genotype that is heterozygous for two pairs of alleles
1) AaBb
2) ABB
3) aaBB
4) AABb
What are the characteristics of modification variability?
1) is massive
2) has an individual character
3) not inherited
4) inherited
5) limited by the reaction rate
6) the range of variability has no limits
Animal breeding methods used in domestication include
1) hybridization
2) individual selection
3) natural selection
4) interbreeding
Selection and its tasks. 10-11 cells.
1. A group of the most similar in structure and activity of animalscreated for agricultural purposes by man is called
A) variety B) view; B) breed D) kind.
2. The method of obtaining new varieties of plants by exposing the body to ultraviolet or X-rays is called
A) heterosis; B) polyploidy; B) mutagenesis; D) hybridization.
3. In breeding to obtain new polyploid plant varieties
C) enhancing the growth of adventitious roots; D) increasing the resistance of plants to adverse conditions.
15. Artificial selection - the preservation by man of organisms with traits of interest to him for a number of generations - contributes to the emergence
A) the diversity of plant varieties and animal breeds; B) various types of plants;
C) different types of animals; D) the diversity of animal and plant populations.
16. To obtain a high yield of potatoes, it should be hilled several times during the summer in order to
A) accelerate the ripening of fruits; B) reduce the number of pests;
C) promote the development of adventitious roots and stolons;
D) improve the nutrition of the roots with organic substances.
