The formation of similar characters in unrelated organisms. Biology test for the first half of the year (grade 11)
Option 1
Part 1.
1. A type of evolutionary change in which unrelated organisms acquire similar characteristics
A) parallelism B) convergence C) divergence D) idioadaptation
2. Metabolism and energy is a sign
A) Characteristic of animate and inanimate bodies
B) By which living things can be distinguished from non-living things
C) How do unicellular organisms differ from multicellular organisms?
D) In which animals differ from humans.
3. Hereditary variability, the struggle for existence and natural selection are
A) Driving forces of evolution B) Results of the revolutionIN)Main directions of evolution
4. C. Linnaeus is the creator of:
A) The first evolutionary theory B) Binary nomenclature and the principle of gradation
C) The principle of gradation and autogenesis D) Binary nomenclature and the principle of hierarchy
5. The flipper-like limbs of whales and dolphins are an example
A) Idioadaptation B) Degeneration C) Aromorphosis 4) Convergence
6. The material for natural selection is:
A) Mutation variability B) Modification variability
C) Biological regression D) Relative fitness
7. A certain set of chromosomes in individuals of one species is considered a criterion:
A) Environmental B) Morphological C) Genetic D) Physiological-biochemical
8. Microevolution ends with the formation of new
A) Species B) Orders C) Families D) Populations
9. The set of external characteristics of individuals is referred to as the species criterion
A) Geographical B) Morphological C) Genetic
D) Ecological
10. What are the consequences of stabilizing selection?
A) preservation of old species B) preservation of individuals with changed characteristics
C) the emergence of new species D) all of the above options.
11. Indicate the correct plant classification scheme:
12. The age structure of the population is characterized
A) The ratio of female and male individuals B) The number of individuals
C) Its density D) The ratio of young and mature individuals
13 A form of selection in which constant change occurs is called
A) stabilizing selection B) driving selection
C) disruptive selection D) no selection
Part 2.
IN 1. What signs characterize biological progress?
A) Reduction in the number of species
B) Expansion of the species range
C) The emergence of new populations, species
D) Narrowing of the species' range
D) Simplification of organization and transition to a sedentary lifestyle
E) Increase in the number of species
AT 2. Evolutionary factors include:
A) Divergence
B) Hereditary variability
B) Convergence
D) The struggle for existence
D) Parallelism
E) Natural selection
B 3. Establish a correspondence between the characteristics of a systematic group and the direction of evolution
1) Variety of species
A) Biological progress
2) Limited range
B) Biological regression
3) Small number of species
4) Widespread ecological adaptations
5) Wide range
6) Decrease in population numbers
Cause of plant death
1) fruits, along with hay, enter the stomach of herbivores
2) plants die from severe frost and drought
3) seeds die in deserts and Antarctica
4) plants crowd out each other
5) Birds eat the fruits
6) plants die from bacteria and viruses
A) intraspecific
B) combating unfavorable conditions
B) interspecific
Answer:
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Animal sign
Direction of evolution
1) reduction of the mole's visual organs
2) presence of suckers on the liver fluke
3) the occurrence of warm-bloodedness
4)
5) loss of the nervous and digestive systems in the pork tapeworm
6) flattened body of flounder
A) idioadaptation (allogenesis)
B) aromorphosis (arogenesis)
C) general degeneration (catagenesis)Answer:
123456
Part C.
C1. Explain why geographic isolation of populations can lead to the formation of new species?
C2.What type of natural selection is shown in the figure? Under what environmental conditions is it observed? What mutations does it retain?
Answers. Option 1
Part A.
1. b
2. b
3. A
4. G
5. 1
6. A
7. V
8. A
9. B
10. A
11. V
12. G
13. b
Part B.
IN 1. BEE
V2.BGE
B3.ABBAAB
B4.AVAABB
B5.AABBVA
Part C.
C1 . 1) new mutations and changes accumulate in isolated populations;
2) as a result of natural selection, individuals with new characteristics are preserved;
3) cessation of interbreeding between individuals of populations, which leads to reproductive isolation and the formation of a new species.
C2.1) Driving selection.
2) Observed in a unidirectional change in environmental conditions.
3) Mutations that lead to other extreme manifestations of the value of a trait are preserved. Mutations that increase the fitness of organisms and hereditary changes in a certain order are fixed.
Option 2
Part A
1. Which of the following organs are homologous?
A) crayfish gills and cat lungs B) elephant trunk and human hand
B) a mole's paw and a monkey's hand
2. Charles Darwin believed that the diversity of species is based on:
A) The struggle for existence B) The ability for unlimited reproduction
B) Hereditary variability and natural selection
3. What evolutionary phenomenon is called divergence?
A) Convergence of characters in unrelated species B) Formation of homologous organs
C) Acquisition of narrow specialization D) Divergence of characters in related species
4. Individuals of two populations of the same species:
A) Can interbreed and produce fertile offspring B) cannot interbreed
C) They can interbreed, but do not produce fertile offspring.
5. Give an example of the manifestation of idioadaptations in plants.
A) The appearance of the seed in gymnosperms B) The appearance of the fruit in flowering plants
C) The appearance of nectaries to attract insects D) The appearance of photosynthesis
6. The physiological criterion of the species is manifested in all individuals in similarity:
A) The structure of the shape of chromosomes B) Life processes
C) External and internal structure D) Lifestyle.
7. A sharp increase in the number of individuals in a population, which results in a lack of resources, leads to:
A) Biological regression B) Biological progress
C) Food specialization D) Intensification of the struggle for existence
8. In the process of macroevolution :
A) New populations appear B) New classes appear
C) New species appear D) Populations change
9. Vestigial organs are an example of evidence of evolution
A) Comparative anatomical B) Embryological C) Biographical
10. The selection of individuals with traits deviating from the average is called:
A) driving B) disruptive C) stabilizing D) sexual.
11. Indicate the correct classification scheme for animals:
A) Species genus family order class type
B) Species genus family order class type
C) Species genus family order class department
D) Species genus order family class type
12. The appearance of what gas in the primary atmosphere of the Earth caused the rapid development of life on land?
A) Hydrogen sulfide B) Oxygen C) Nitrogen D) Carbon dioxide
13. Imitation of a less protected organism of one species by a more protected organism of another species
A) camouflage B) mimicry C) threatening coloring
D) protective coloring
Part B.
IN 1. What evolutionary changes can be attributed to aromorphoses?
A) The appearance of a flower
B) Formation of organs and tissues in plants
B) The appearance of thermophilic bacteria
D) Atrophy of roots and leaves of dodder
D) Specialization of some plants to certain pollinators
E) Constant body temperature
AT 2. What features illustrate the stabilizing form of natural selection?
A) Operates in changing environmental conditions
B) Operates under constant environmental conditions
C) Maintains the reaction norm of the trait
D) Changes the average value of a characteristic either towards a decrease in its value or towards an increase
D) Controls functioning organs
E) Leads to a change in the reaction norm
B 3. Establish a correspondence between the sign of the liver fluke and the criterion of the species for which it is characteristic.
1) The larva lives in water
A) Morphological
2) Body flattened
B) Ecological
4) Feeds on host tissues
5) Has two suction cups
6) The digestive system has a mouth opening
AT 4. Establish a correspondence between the death of plants and the form of struggle for existence.
Cause of plant death
A form of struggle for existence
1) plants of the same species crowd out each other
2) plants die from viruses, fungi, bacteria
3) seeds die from severe frosts and drought
4) plants die from lack of moisture during germination
5) people and cars trample young plants
6) Birds and mammals feed on plant fruits
A) Intraspecific
B) Interspecific
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C) combating unfavorable conditions
Answer:
AT 5. Establish a correspondence between an animal’s trait and the direction of evolution to which it corresponds
Animal sign
Direction of evolution
1) occurrence of sexual reproduction
2) formation of cetacean flippers
3) the appearance of a 4-chambered heart
4) the emergence of an autotrophic mode of nutrition
5) transformation of leaves into spines in desert plants
6) loss of leaves, roots and chlorophyll in dodder
A) general degeneration (catagenesis)
B) idioadaptation (allogenesis)
B) aromorphosis (arogenesis)
Part C.
C1 . How does ecological speciation occur in nature?
C2.
What type of natural selection is shown in the picture? Under what environmental conditions is it observed? What mutations does it retain?
Part A.
1. b
2. V
3. G
4. A
5. V
6. b
7. G
8. b
9. A
10. b
11. A
12. b
13. b
Part B.
Answers. Option 2
IN 1. ABE
V2.BVD
AT 3. BABBAA
B4.AABBVA
Part C.
C1 . B5.VBVVBA
2) 1) Populations of the same species find themselves in different conditions, but within the same range;
3) Natural selection preserves individuals with mutations that are beneficial for life in certain environmental conditions;AND
From generation to generation, the genetic composition of individuals in a population changes greatly, as a result of which individuals from different populations of the same species stop interbreeding and become new species.C2
2) 1) This is stabilizing selection;
3) Observed under relatively constant environmental conditions;
Preserves mutations leading to less variability in the average value of a trait.
Biology. General biology. Grade 11. Basic level Sivoglazov Vladislav Ivanovich
11. Speciation as a result of evolution
Remember!
What is a species?
What types of ancient plants and animals do you know?
What role does isolation play in the process of evolution? Speciation Currently, several million different species live on the globe, and over the entire existence of the Earth, according to scientists, there were 50–100 times more of them. How did all this gigantic diversity arise?
Methods of speciation. The famous American zoologist and evolutionist Ernst Mayr made a great contribution to solving the problems of speciation. He identified three main methods of speciation (Fig. 34).
The first way is to convert one type to another (A to B). At the same time, the total number of species does not change, because gradually one species is replaced by another, new species.
The second method is based on the hybridization of two species, resulting in the formation of a third, new species (interspecific formation). As a rule, the original species do not disappear, so the total number of species increases (+1). An example of such speciation is the emergence of cultivated plum (2 n= 48) as a result of sloe hybridization (2 n= 32) and cherry plum (2 n = 16).
Rice. 34. Three main methods of speciation
The third method, which Mayr called true speciation, is associated with the divergence of characters. This method was studied in detail and described by Charles Darwin. If the original and newly formed species remain viable, the number of species increases. This is how most species were formed.
Pathways of speciation. If individuals belonging to different populations within the same species interbreed and produce fertile offspring, the species is a single entity. The flow of genes between intraspecific populations forms a single species gene pool. For a new species to form, isolation must occur between populations. As a result, the exchange of genes between isolated populations stops, interpopulation differences accumulate, which can subsequently lead to the transformation of such populations into independent genetic systems, first species, and then larger taxa (Fig. 35).
Depending on the isolating mechanism, two main paths of speciation can be distinguished: geographical and ecological.
Rice. 35. The occurrence of isolation between populations can lead to the formation of new species
Geographic speciation . When populations are spatially isolated, geographic speciation occurs. If a certain population migrated beyond the range of the original species, lost contact with other species populations and found itself in different conditions, the accumulation of adaptations to these new living conditions can lead to the formation of a new species.
Also, geographic speciation can occur when the original integral area of the parent species is divided into several isolated independent areas. Such isolation occurs as a result of global geological processes: continental drift, mountain building, the formation of water barriers, etc. A classic example of such speciation is the finches that Darwin studied on various Galapagos Islands.
An example of speciation through fragmentation (from the Latin fragmentum - fragment, piece) of the range of the parent species is the emergence of different types of lily of the valley (Fig. 36). Several million years ago, the original ancestral species of lily of the valley was widespread in the forests of Eurasia, but due to glaciation, its range split into several independent territories. The lily of the valley survived only in areas that were not affected by the glacier: in the south of the Far East, in Transcaucasia and in southern Europe. Subsequently, these three isolated populations developed independently, which led to the formation of several new species, differing in the size and color of leaves and corollas.
Rice. 36. Speciation through fragmentation of the range of the parent species. Formation of different types of lily of the valley
Speciation occurs very slowly, over hundreds of thousands and millions of years as a result of changes in hundreds of thousands of generations. If we trace the process of successive separation of land fragments from a single ancient continent, we will be able to identify a clear correlation. Islands and continents, which have a longer history of independent existence, differ much more in flora and fauna.
Ecological speciation. Within the range of the original species, ecological speciation occurs. This can happen in several ways. One of them is the rapid emergence of new species through a multiple increase in the number of chromosomes ( polyploidization). For example, the original tobacco species has 12 chromosomes, but forms with 24, 48, and 72 chromosomes are known.
Another method is based on the ecological isolation of species. In this case, differences in living conditions serve as isolating barriers, resulting in the formation of ecological subspecies that prefer certain ecological niches. In the future, such subspecies can give rise to new independent species (§ 5, different types of oaks growing on different soils).
A similar method of speciation occurs in animals. For example, the apple moth has two ecological groups that prefer to feed and breed on two different types of plants - hawthorn and apple. As it turns out, host recognition and preference is controlled by a single gene. Consequently, a mutation arising in this gene can initiate the formation of ecological races, then subspecies and subsequently species. Evidence that speciation is complete is the occurrence of reproductive isolation (the impossibility of crossing) even with the disappearance of isolating barriers.
The resulting new species subsequently enters into complex interspecific relationships, which determine its subsequent fate: prosperity, death, or disintegration into new species.
Review questions and assignments
1. Compare the three main modes of speciation.
2. Characterize the mechanisms of the main pathways of speciation.
3. What role does isolation play in the process of speciation?
4. Give examples of geographic and ecological speciation.
5. What is the significance of spatial isolation for the formation of new species?
Think! Do it!
Explain why hybrids of different plant species are more common in nature than different animal species.
Work with computer
Refer to the electronic application. Study the material and complete the assignments.
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Speciation within the range of the original species. Currently, many scientists divide speciation occurring within the range of the original species into two options. Speciation based on the ecological isolation of species, in which the leader is a change in the preferences and activity of the individuals themselves, is called sympatric speciation. Another option is parapatric speciation, which occurs through polyploidization or other genetic changes. In this case, new forms arise within one generation, i.e., genetic isolation immediately occurs. In order to prove their competitiveness, individuals with an altered genetic apparatus must withstand fierce competition with other individuals well adapted to living conditions. Therefore, this type of speciation is of limited importance. The exception is cases of occurrence in polyploid forms of plants that quickly spread due to vegetative propagation.
Types of evolutionary changes. The main types of evolutionary change are divergence, convergence, parallelism and phyletic evolution.
Divergence. Divergence(from Latin divergantia - divergence) is the most common type of evolutionary process. The concept of divergence was introduced by Charles Darwin, meaning by it the divergence of characters in the process of evolution. In this case, two or more taxa are formed, descending from a common ancestor. Such a divergence of characteristics and groups occurs if the living conditions of the daughter group change. For example, the appearance of a five-fingered lever-type limb helped ancient vertebrates master the terrestrial environment. However, depending on the lifestyle and type of habitat, the limbs of different groups of vertebrates have undergone significant changes and now perform different functions (see Fig. 6). Such organs that have a common origin and perform different or similar functions are called homologous organs(see also § 13).
Convergence. Convergence- this is a type of evolutionary change, as a result of which similar characteristics appear in organisms that are unrelated to each other, that is, having different origins. Most often, convergence occurs when different species of organisms populate similar types of habitats (Fig. 37). Thus, convergent similarity is the result of adaptations to the same environmental conditions. The gills of fish and the gills of crayfish, which perform respiratory functions, are similar. However, the gills of fish develop on the partitions between the gill slits that penetrate the pharynx, and the gills of crayfish are thread-like outgrowths of the chest limbs. The wings of butterflies and bats, the eyes of humans and octopuses, the burrowing limbs of moles and mole crickets (Fig. 38) - all these organs are formed from different embryonic rudiments. Organs that perform similar functions but have different origins are called similar(see also § 13).
Rice. 37. Astrophytum star cactus from Texas (right) and Euphorbia obesa from South Africa (left). The two species live in similar natural conditions and have acquired similar forms through convergent evolution. Moreover, they belong not only to different families, but also to different orders. Despite favorable conditions, cacti are almost completely absent in Africa
Parallelism. Parallelism- this is a type of evolutionary change, the result of which is the formation of similar characteristics in related forms. For example, cetaceans and pinnipeds, independently of each other, switched to living in the aquatic environment and acquired the corresponding devices - flippers. Mammals of the tropical zone, living on different continents in similar climatic conditions, have a certain general similarity (Fig. 39).
Rice. 38. Similar organs
Rice. 39. Parallelism in the body structure of mammals inhabiting the rain forests of Africa and South America: pangolin (left) and giant armadillo (right)
Phyletic evolution. Phyletic evolution- this is a type of evolutionary transformation in which ancestral taxa are gradually transformed into new (daughter) taxa without the formation of side branches. In this case, a continuous series of taxa is formed, in which each is a descendant of the previous one and the ancestor of the subsequent one.
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115. Name the term that denotes the independent formation of similar characters in related organisms, based on homologous structures.
1) divergence
2) parallel evolution
3) convergence
4) mimicry
5) aromorphosis
116. What does the similarity of the embryos of organisms of the two compared classes of animals indicate?
1) about the formation of these embryos under the same conditions
2) about the presence of kinship and monophyletic origin (from one ancestor) of these two classes
3) about the origin of these classes from unrelated ancestors
4) about polyphilic origin (from several ancestors)
117. Name a phenomenon, an example of which is the similarity of body shape in a shark, ichthyosaur and dolphin.
1) divergence
2) parallel evolution
3) convergence
4) mimicry
5) aromorphosis
118. The limbs of mammals of different species differ significantly from each other in structure, which is the result of the adaptation of mammals of different species to different environmental conditions. Indicate the phenomenon of which the above fact is an example.
1) convergence
2) divergence
3) parallel development
119. Name the form (method, path) of biological progress, which includes the development of lungs in amphibians and a four-chambered heart in birds, the transformation of paired fins of fish into paired limbs of amphibians.
1) aromorphosis
2) idioadaptation
3) general degeneration
120. Determine the characteristic by which all of the following pairs of characteristics, except one, are combined into one group.
Indicate a couple of signs that are “extra” among them.
1) potato tuber and onion bulb
2) squid eye and horse eye
3) wing of a butterfly and elytra of a cockchafer
4) cactus spines and plant bud scales
5) forelimbs of an elephant and a monkey
121. There are several indicators (criteria) of the biological progress of a particular taxon - a systematic group of organisms (species, genus, class, etc.). Find these indicators among the answers and indicate the characteristic that is NOT such an indicator (criterion).
1) increasing increase in the number of individuals
2) expansion of the range
3) the formation of adaptations (adaptation) to narrow local conditions of existence
4) an increase in the number of daughter (subordinate) groups within this taxon
1) convergence
2) divergence
122. The eyes of cephalopods and mammals are very similar, although these most perfect sense organs arose in them during evolution absolutely independently and from different tissues and structures.
Indicate the phenomenon exemplified by the appearance of these organs.
3)parallel development
123. What is A.I. Oparin’s contribution to the development of ideas about the origin of life on Earth?
3) proved the impossibility of spontaneous generation of microorganisms
4) proved the impossibility of the direct emergence of highly organized living beings from inanimate nature
124. Scientists divide the history of the Earth and life on it into several periods of time - geological eras. Which one is the youngest?
1) Paleozoic 2) Proterozoic
3) Archean
4) Cenozoic
5) Mesozoic
125. Which of the following is NOT aromorphosis - one of the ways (paths) of biological progress?
1) the appearance of roots in terrestrial plants
2) the appearance of a flower in flowering plants
3) the appearance of photosynthesis in ancient cellular forms
4) the appearance of spines in cacti and rose hips
5) formation of conductive tissues in land plants
126. Name the term used to designate in different species of organisms those organs that have the same structural plan, develop from similar rudiments and perform both similar and different functions.
1) homologous3) similar
2) non-homologous 4) alternative
By comparing the genome sequences of dolphins and bats - mammals capable of echolocation - European scientists have elucidated the genetic pathways of convergent evolution. Convergence, that is, the emergence of similar traits in unrelated organisms, was considered the result of the evolution of different sets of genes: the probability of the appearance of similar mutations in similar genes seems too insignificant. But, as it turned out, echolocation, a complex adaptive trait, arose in dolphins and bats precisely due to similar mutations in similar genes. This changes our understanding of the genetic essence of convergence, and also shows that the results of using molecular methods for phylogenetic reconstructions should be treated with caution.
Suppose we construct different phylogenetic trees (see diagrams in Figs. 2 and 3), based on different hypotheses about the origin of echolocation. One tree will reflect overall molecular similarity - this is the accepted approach. The other will force all echolocator bats to unite into one monophyletic clade, breeding them with their counterparts incapable of echolocation and, naturally, with dolphins. The third tree will unite all animal echolocators in general - both bats and dolphins, separating them from other non-echolocators. No matter how absurd the last two trees may seem to us, we can analyze them in the same ways as those trees that seem acceptable to us. Moreover, in the course of calculating individual sequences of specific genes, it turns out that these ridiculous trees are actually quite good. Having identified a set of such genes, it will be possible to confidently conclude that convergent evolution was at work at these sites. This is exactly what geneticists reasoned when they began to calculate the similarity of 2326 orthologous coding genes.
Each of the orthologous genes was compared with each and for each it was estimated which of the phylogenetic schemes suited it best, that is, for which tree the genetic similarity would be b O greater. There were many loci in five echolocator species for which “absurd” phylogenetic trees were more suitable (824 loci for the second tree and 392 for the third). In other words, it was these loci that convergent evolution worked with.
These characteristics were most clearly manifested in genes associated with hearing or deafness. For example, convergence affected genes responsible for the formation of the cochlea, as well as those encoding the development of hair cells in the inner ear. Also, a clear statistical signal of convergent evolution was found in genes that are somehow related to vision. This should hardly be surprising: both dolphins and bats are adapted to low light. Therefore, both the molecular and regulatory systems of visual perception were adjusted accordingly. However, the functions of many genes with clear convergent signals remain unknown.
An important part of the work was testing the effect of selection on “convergent” genes: whether convergence was neutral or formed as a result of driving selection. This issue was resolved in a classical way - by comparing the number of synonymous and non-synonymous substitutions (see Rate of nucleotide substitutions). It turned out that the number of nonsynonymous substitutions exceeded the number of synonymous ones; Therefore, in the case of echolocation, we are not dealing with neutral drift, but with driving selection that supports the formation of adaptive characters.
This study is important to note for two reasons. First, reading entire genomes has become a routine and apparently inexpensive endeavor. The fact that the authors of this work read and deciphered the genomes of four species of bats using equipment and the latest technologies from Illumina is briefly reported in the methodological part of the work. The authors were well aware that the time for excitement about the very possibility of reading genomic sequences and even the high accuracy of their decoding had passed. The time has come for the results that loomed in the future behind these delights.
The second reason relates more to biological methodology, namely to phylogeny techniques. The century of dominance of morphological systematics gave way to the era of molecular phylogenetics. If previously family trees were reconstructed on the basis of morphological similarities and differences and/or on the basis of morphological homologies, now it is customary to focus on the amount of similarity between amino acid or nucleotide sequences. The choice in favor of molecular phylogenetics was made not least because of the difficulties of distinguishing between convergences and common origins.
In molecular phylogenetics, superficial convergent similarity was thought to be of little importance, since the genetic changes to achieve the same morphological outcome are always different. Therefore, molecular phylogenetics could not be too worried that instead of kinship, ecological community would emerge.
But, as it now turns out, this is not so. If our geneticist were not very lucky and he took those same 824 similar loci or, even worse, 390 loci similar for our third tree to build his family tree of echolocation, he would get absurd phylogenies. And he would have every right to defend them, citing a good and reliable statistical signal! About the same as if a morphologist defended the common origin of dolphins and bats, appealing to amazing echolocation. And this is exactly what molecular phylogeneticists tried to get away from, but only worse, because not everyone will dare to argue with statistics. So this work once again shows that each method has its own limitations and its own range of applicability. Molecular phylogenetics has yet to determine it.