Criteria for describing the species. Morphological criterion of the species

Studying the composition of DNA is an important task. The presence of such information makes it possible to identify the characteristic features of all living organisms and study them.

Definition

The species represents the basic form of organization of earthly life. It is considered the main unit of classification of biological objects. The problems associated with this term are best analyzed from a historical perspective.

Pages of history

The term "species" has been used to characterize objects since ancient times. Carl Linnaeus (Swedish naturalist) proposed using this term to characterize the discreteness of biological diversity.

When identifying species, differences between individuals in a minimum number of external parameters were taken into account. This method was called the typological approach. When assigning an individual to a species, its characteristics were compared with the description of those species that were already known.

In cases where it was not possible to make a comparison using ready-made diagnoses, a new species was described. In some cases, incidental situations arose: females and males belonging to the same species were described as representatives of different classes.
TO end of the 19th century century, when there was already enough information about mammals and birds living on our planet, the main problems of the typological approach were identified.

In the last century significant development received genetics, so the species began to be considered as a population with a unique, similar gene pool, which has a certain “protection system” for its integrity.

It was in the 20th century that similarity in biochemical parameters became the basis of the species concept, authored by Ernst Mayer. A similar theory described in detail the biochemical criterion of the species.

Reality and appearance

In Charles Darwin's book "The Origin of Species" we're talking about about the possibility of mutual transformation of species, the gradual “emergence” of organisms with new characteristics.

Type criteria

They mean the sum of some characteristics inherent in only one species. Each has its own characteristic parameters that need to be examined in more detail.

The physiological criterion is the similarity of life processes, for example, reproduction. Crossbreeding between representatives of different species is not expected.

The morphological criterion assumes an analogy in the external and internal structure of individuals of the same species.

The biochemical criterion of a species is associated with specificity nucleic acids and proteins.

It assumes a specific set of chromosomes that differ in structure and structural complexity.

The ethological criterion is related to the habitat. Each species is characterized by its own areas of occurrence in the natural environment.

Main features

The species is considered a qualitative stage of living nature. It can exist as a result of various intraspecific relationships that ensure its evolution and reproduction. Its main feature is a certain stability of the gene pool, which is maintained by the reproductive isolation of some individuals from other similar species.

To maintain unity, free crossing between individuals is used, leading to a constant flow of genes within the generic community.

Each species adapts to the conditions of a certain area over several generations. The biochemical criterion of a species assumes a gradual restructuring of its genetic structure caused by evolutionary mutations, recombinations, and natural selection. Such processes lead to heterogeneity of the species, its disintegration into races, populations, and subspecies.

To achieve genetic isolation, it is necessary to separate related groups by seas, deserts, and mountain ranges.

The biochemical criterion of a species is also associated with ecological isolation, which consists in the discrepancy between the timing of reproduction and the habitat of animals in different tiers of the biocenosis.

If interspecific crossing occurs or hybrids with weakened characteristics appear, then this is an indicator of the qualitative isolation of the species, its reality. K. A. Timiryazev believed that a species is a strictly defined category that does not involve modifications, and therefore does not exist in real nature.

The ethological criterion explains the process of evolution in living organisms.

Population

The biochemical criterion of a species, examples of which can be considered for different populations, is of particular importance for the development of the species. Within the range, individuals of the same species are distributed unevenly, since living nature does not have the same conditions for reproduction and existence.

For example, mole colonies spread only in individual meadows. There is a natural breakdown of the population of a species into populations. But such distinctions do not eliminate the possibility of crossing between individuals located in border areas.

The physiological criterion is also associated with the fact that it undergoes significant fluctuations in different seasons and years. A population is a form of existence under certain environmental conditions; it is rightfully considered the unit of evolution.

They exist for a long period of time in some part of the range, to some extent isolated from other populations. What is the biochemical criterion of the species? If individuals of one population have a significant number of similar characteristics, internal crossing is allowed. Despite this process, populations are characterized by genetic heterogeneity due to constantly emerging heritable variability.

Darwinian divergence

How does the theory of divergence of characteristics of the properties of descendants explain the biochemical criterion of a species? Examples of different populations prove the possibility of the existence, despite external homogeneity, of a significant number of differences in genetic characteristics. This is what makes it possible for a population to evolve. Survive under conditions of strict natural selection.

Types of species

The division is carried out on the basis of two criteria:

morphological, which involves identifying differences between species;
assessing the degree of genetic individuality.

When describing new species, some difficulties often arise, which are associated with the incompleteness and gradualness of the process of speciation, as well as with the ambiguous correspondence of the criteria to each other.

The biochemical criterion of which has different interpretations allows us to distinguish the following “types”:

monotypic is distinguished by an unbroken vast range, in which geographic variability is poorly expressed;
polytypic implies the inclusion of several subspecies, isolated geographically;
polymorphic presupposes the existence within one population of several morpho-groups of individuals that differ significantly in color, but can interbreed. The genetic basis of the phenomenon of polymorphism is quite simple: the differences between morphs are explained by the influence of different alleles of one gene.

Examples of polymorphism

Adaptive polymorphism can be considered using the example of the praying mantis. It is characterized by the existence of brown and green morphs. The first option is difficult to detect on green plants, while the second is perfectly camouflaged in dry grass and tree branches. When mantises of this species were transplanted to a different background, adaptive polymorphism was observed.

Let's consider hybridogenic polymorphism using the example of the Spanish wheatear. Males of this species are in black-throated and white-throated morphs. Depending on the characteristics of the area, this ratio has certain differences. As a result of laboratory studies, a hypothesis was put forward about the formation of the black-necked morph in the process of hybridization with the bald wheatear.

Twin species

They can live together, but there is no interbreeding between them, and slight morphological differences are observed. The problem of difference similar types is determined by the complexity of isolating their diagnostic characteristics, since such twin species are well versed in their “taxonomy”.

A similar phenomenon is typical for those groups of animals that use smell when searching for a partner, for example, rodents and insects. Only in some cases is a similar phenomenon observed in organisms that use acoustic and visual signaling.

Pine and spruce crossbills are examples of sibling species among birds. They are characterized by living together over a large area that covers the Scandinavian Peninsula and Northern Europe. But despite this, it is not typical for birds to interbreed. The main morphological differences between them are in the size of the beak; it is significantly thicker in the pine tree.

Half-species

Considering that the process of speciation is long and thorny, forms may appear for which it is quite problematic to distinguish their status. They did not become a separate species, but they can be called a semi-species, since there are significant morphological differences between them. Biologists call similar forms“borderline cases”, “semi-species”. In nature they are found quite often. For example, in Central Asia The common sparrow coexists with the black-breasted sparrow, which is similar in characteristics but has a different color.

Despite sharing the same habitat, there is no hybridization between them. In Italy there is a different form of sparrow, which appeared as a result of the hybridization of the Spanish and the house sparrow. In Spain they exist together, but hybrids are considered rare.

Finally

In order to explore the diversity of life, man had to create a certain system of classification of organisms to divide them into separate species. A species is a minimal structural unit that has developed historically.

It is characterized as a set of individuals that are similar in physiological, morphological, and biochemical characteristics, producing high-quality offspring adapted to specific environmental conditions. Such characteristics allow biologists to conduct a clear classification of living organisms.

1. What is a species?

Answer. Species (lat. species) - a taxonomic, systematic unit, a group of individuals with common morphophysiological, biochemical and behavioral characteristics, capable of mutual crossing, producing fertile offspring in a number of generations, naturally distributed within a certain area and similarly changing under the influence of factors external environment. A species is a really existing genetically indivisible unit of the living world, the main structural unit in a system of organisms.

2. What types of plants and animals do you know?

Answer. Types of plants: European swimsuit, Altai anemone, Lyubka bifolia, needle-leaved carnation, lady's slipper, etc.

Types of animals: Brown bear, Siberian roe deer, common lynx, pine marten, black ferret, European mink. striped chipmunk, flying squirrel, gray partridge, black grouse and others.

Questions after § 53

1. Define a biological species.

Answer. Biological species- this is a set of individuals that have the ability to interbreed with the formation of fertile offspring; inhabiting a certain area; possessing a number of common morphological and physiological characteristics and similarities in relationships with the biotic and abiotic environment.

A biological species is not only a systematic category. This is a holistic element of living nature, isolated from other species. The integrity of the species is manifested in the fact that its individuals can live and reproduce only by interacting with each other thanks to the mutual adaptations of organisms developed in the process of evolution: the peculiarities of the coordination of the structure of the maternal organism and the embryo, signaling and perception systems in animals, common territory, similarity of life habits and reactions to seasonal climate changes, etc. Species adaptations ensure the preservation of the species, although sometimes they can harm individual individuals. River perch, for example, feeds on its own young, due to which the species survives when there is a lack of food, even despite the loss of part of the offspring. Each species exists in nature as a historically emerged integral formation.

2. What species criteria do you know?

Answer. The characteristic features and properties by which some species differ from others are called species criteria.

The morphological criterion is the similarity of the external and internal structure of organisms. Carl Linnaeus, for example, defined species as entire groups of organisms distinct from others life forms according to the characteristics of the structure. In other words, the presence of structural features that make a certain group of organisms similar to each other and at the same time different from all other groups is the criterion for classifying them as a given species.

Individuals within a species are sometimes so variable that it is not always possible to determine the species based on morphological criteria alone. There are species that are morphologically similar. These are twin species that are discovered in all systematic groups. For example, two twin species are known in black rats - with 38 and 49 chromosomes; the malaria mosquito has 6 twin species, and the small spined lance fish, widespread in fresh water bodies, has 3 similar species. Twin species are found among the most various organisms: fish, insects, mammals, plants, but individuals of such twin species do not interbreed.

The genetic criterion is a set of chromosomes characteristic of each species; their strictly defined number, sizes and shapes, DNA composition. Chromosome set is the main one specific character. Individuals of different species have different sets of chromosomes, so they cannot interbreed and are reproductively limited from each other in natural conditions.

Physiological criterion - the similarity of the body’s reactions to external influences, rhythms of development and reproduction. This criterion is based on the similarity of all life processes, and above all reproduction. Representatives of different species, as a rule, do not interbreed or their offspring are infertile. However, there are exceptions. For example, dogs can produce offspring by mating with wolves. Hybrids of some species of birds (canaries, finches), as well as plants (poplars, willows) can be fertile. Consequently, the physiological criterion is also insufficient to determine the species identity of individuals.

An ecological criterion is a species’ characteristic position in natural communities, its connections with other species, and sets of environmental factors necessary for existence.

Geographic criterion - area of distribution, a certain area occupied by a species in nature.

The historical criterion is the community of ancestors, a single history of the emergence and development of the species.

3. What is the integrity of the species, how is it manifested?

Answer. View is a complete system. The view is a single integral system. The integrity of the species is ensured by its isolation from other species due to a specific chromosome set (reproductive isolation).

The integrity of a species is also determined by the connections that its individuals form in populations and subspecies. Relationships between males and females, parents and their offspring, individuals different ages in a flock, herd and colony they allow one to successfully reproduce, take care of offspring, provide protection from enemies, etc. The entire set of connections ensures the existence of the species as an integral system.

4. Why is it important to preserve species in nature?

Answer. Biological diversity on the planet is presence on it large quantity species of all kingdoms: animals, plants, fungi. The task of preserving them is one of the main ones in ecology. Planet Earth is truly rich, therefore, a person is obliged to protect this wealth, at least so that it goes to the next generations of people. So that grandchildren and great-grandchildren can see wonderful animals, beautiful corners of nature, and can use medicinal plants. Any plant or animal (even the smallest one) is part of the biogeocenosis, and in general, is included in the entire ecosystem of the Earth. The body participates in the cycle of substances, being a link in the food chain. Plants that are producers synthesize nutrients using solar energy. Consumers consume energy accumulated by plants and other animals, deritophages “recycle” dead animals, and decomposers finally decompose nutrient residues. Thus, each organism occupies a certain place in nature and performs a certain role. The disappearance of one link can cause the disappearance of several more, changing the entire chain. Not only will there be impoverishment the food chain, but also an imbalance of species in the ecosystem. Some species may increase disproportionately in number and cause ecological disaster. For example, an unprecedented proliferation of locusts can deprive entire regions of crops. By preserving the wealth of species on the planet, we thus maintain the stability of ecosystems and ensure the safety of life of all species, including human life. In addition, scientists want to preserve the genetic information of each species, counting on future technologies that will make it possible to recreate animal world of the past, for example, in isolated recreation areas (parks), to recreate extinct and currently endangered species of animals and plants.

In the process of practical human activity, the concept of a species was formed. When describing animals, this concept was already used by Aristotle. However, for a fairly long period it was not endowed with scientific content and was used as a logical term. The concept in question acquired the status of a classification unit in the process of development of taxonomy. John Ray (English naturalist) developed the idea of a species as a component of taxonomy. At the same time, scientists identified three most important characteristics of this unit. Thus, a species, according to Ray, is a set of organisms that are characterized by a common origin. This systematic unit unites organisms that are similar in morphological and physiological characteristics. In addition, it is a self-reproducing system.

Rey considered origin the main indicator. Thus, the naturalist classified similar plants that reproduce their own kind from their seeds as one species.

A significant expansion and also its deepening occurred thanks to the work of Linnaeus, who showed that a species is a real elementary and stable unit of living nature, isolated from other species. This concept began to be used as a main and plants. However, in those days, appearance was considered as a consequence of creative action.

Lamarck proclaimed in his works the position that in nature there are unchanging systematic units of plants and animals. Species are constantly transforming, changing, moving into other species. In this regard, according to Lamarck, the old systematic unit cannot be separated from the new one. Thus, the French naturalist came to the conclusion of denying the reality of the species, while affirming the idea of development.

Darwin's teaching was based on a different position. This position was scientifically substantiated. In accordance with it, developing real view caused by historical development under the influence of In accordance with Darwinian teachings, it was carried out comprehensive study systematic units. Thus, a study was carried out of the morphological criterion of the species, as well as an experimental, genetic study of the structure and ways of its formation. These events were of decisive importance in substantiating the population aspect of a systematic unit as the main form of development and existence of the organic world as a whole.

Today it is believed that the organic environment includes a diversity of life forms. Moreover, “species” is a universal phenomenon for all living nature. The systematic unit under consideration is formed in the course of evolutionary transformations caused by natural selection. As a result, it represents a specific stage (link) in the development of living organisms and is the main form of existence of life on the planet.

One type differs from another by a set of common features - criteria. Together, these features form the reality of systematic units.

Morphological ones are based on the presence of certain hereditary characteristics in all individuals of one species. Individuals within the same systematic unit, in other words, have similar external and internal structure. The morphological criterion of a species is considered a fairly convenient and simple character. Moreover, this characteristic was used by taxonomists earlier than other characteristics and was the main one for a certain period. However, it should be noted that the morphological criterion of a species is rather relative. This feature is necessary, but not sufficient. The morphological criterion of a species does not allow distinguishing systematic units that have significant similarities in structure, but do not interbreed with each other. For example, systematic twin units. Thus, the name includes about fifteen species, indistinguishable in appearance, but previously considered one species. It has been established that about 5% of all systematic units are twins. Thus, the morphological criterion of a species cannot be the only sign differences.

A species is a collection of individuals that are similar in terms of species criteria to such an extent that they can naturally interbreed and produce fertile offspring.

Fertile offspring are those that can reproduce themselves. An example of infertile offspring is a mule (a hybrid of a donkey and a horse), it is infertile.

Type criteria- these are characteristics by which 2 organisms are compared to determine whether they belong to the same species or to different ones.

Morphological - internal and external structure.
Physiological-biochemical - how organs and cells work.
Behavioral - behavior, especially at the time of reproduction.
Ecological - a set of environmental factors necessary for the life of a species (temperature, humidity, food, competitors, etc.)
Geographical - area (area of distribution), i.e. the territory in which the species lives.
Genetic-reproductive - the same number and structure of chromosomes, which allows organisms to produce fertile offspring.

Type criteria are relative, i.e. A species cannot be judged by one criterion. For example, there are twin species (in the malaria mosquito, in rats, etc.). They do not differ morphologically from each other, but have a different number of chromosomes and therefore do not produce offspring. (That is, the morphological criterion does not work [is relative], but the genetic-reproductive criterion does).

1. Establish a correspondence between the honey bee trait and the criterion of the species to which it belongs: 1) morphological, 2) ecological. Write numbers 1 and 2 in the correct order.
A) social way of life
B) difference in size of males and females
B) development of larvae in honeycombs
D) the presence of hairs on the body
D) feeding on nectar and pollen of flowers
E) compound eyes

Answer

2. Establish a correspondence between the characteristic characterizing the sand lizard and the species criterion: 1) morphological, 2) ecological
A) the body is brown in color
B) eats insects
B) inactive at low temperatures
D) respiratory organs - lungs
D) reproduces on land
E) the skin does not have glands

Answer

3. Establish a correspondence between the characteristic of the sanding lizard and the criterion of the species that it illustrates: 1) morphological, 2) ecological
A) winter torpor
B) body length 25-28 cm
B) spindle-shaped body
D) differences in coloration of males and females
D) living on the edges of forests, in ravines and gardens
E) feeding on insects

Answer

4. Establish a correspondence between the feature large pond snail and the criterion of the species for which it is characteristic: 1) morphological, 2) ecological. Write numbers 1 and 2 in the correct order.
A) sense organs – one pair of tentacles
B) Brown color shells
B) inhabits fresh water bodies
D) feeds on the soft tissues of plants
D) spirally twisted shell

Answer

5. Establish a correspondence between the trait of a mole and the criterion of the species to which this trait belongs: 1) morphological, 2) ecological. Write numbers 1 and 2 in the correct order.
A) the body is covered with short hair
B) the eyes are very small
B) digs a hole in the soil
D) the front paws are wide - digging
D) eats insects
E) reproduces in the nesting chamber

Answer

1. Establish a correspondence between the characteristic of the species Wild pig (wild boar) and the criterion of the species to which this characteristic belongs: 1) morphological, 2) physiological, 3) ecological. Write down the numbers 1, 2 and 3 in the correct order.
A) The number of piglets in a litter depends on the fatness of the female and her age.
B) Pigs are active during the day.
C) Animals lead a herd lifestyle.
D) The color of individuals is from light brown or gray to black, the piglets are striped.
D) The method of obtaining food is digging the ground.
E) Pigs prefer oak and beech forests.

Answer

2. Establish a correspondence between the characteristic of the species Common Dolphin (Snow-sided Dolphin) and the criterion of the species to which this characteristic belongs: 1) morphological, 2) physiological, 3) ecological
A) Predators, they feed on different types of fish.
B) Males are 6-10 cm larger than females.
B) Animals have mastered aquatic environment a habitat.
D) Body size 160-260 centimeters.
D) Pregnancy in females lasts 10-11 months.
E) Animals lead a herd lifestyle.

Answer

3. Establish a correspondence between the characteristics of the Asian Porcupine species and the criterion of the species to which it is classified: 1) morphological, 2) physiological, 3) ecological. Write the numbers 1, 2 and 3 in the correct order.
A) The paws are equipped with long claws.
B) Animals eat plant foods.
C) Pregnancy of females lasts 110-115 days.
D) The longest and sparsest needles grow on the lower back of animals.
D) The female produces milk after giving birth to her young.
E) Animals lead night look life.

Answer

4. Establish a correspondence between the characteristics of the pork tapeworm and the criteria of the species: 1) morphological, 2) ecological, 3) physiological. Write the numbers 1, 2, 3 in the order corresponding to the letters.
A) body size up to 3 m
B) on the head, in addition to suction cups, there are hooks
C) the adult worm lives in the small intestine of humans
D) reproduces parthenogenetically
D) larvae develop in the body of domestic and wild pigs
E) pork tapeworms are highly fertile

Answer

5. Establish a correspondence between the characteristics of the Blue Whale species and the criteria of the species: 1) morphological, 2) physiological, 3) ecological. Write numbers 1-3 in the order corresponding to the letters.
A) Females breed every two years.
B) The female produces milk for seven months.
C) Whale lice and barnacles settle on the skin of whales.
D) The whalebone plates have a pitch-black color.
D) The length of some individuals reaches 33 meters.
E) Puberty of individuals occurs at four to five years of age.

Answer

6. Establish a correspondence between the characteristics of the sanding lizard and the criterion of the species to which it is classified: 1) morphological, 2) ecological, 3) physiological. Write numbers 1-3 in the order corresponding to the letters.
A) terrestrial limbs
B) the presence of horny scales on the skin
B) development of the embryo in the egg
D) laying eggs on land
D) unstable body temperature
E) feeding on insects

Answer

1. Establish a correspondence between examples and types of adaptation: 1) morphological, 2) ethological, 3) physiological. Write the numbers 1, 2, 3 in the order corresponding to the letters.
A) dead nettle resembles stinging nettle
B) the chipmunk stores food for the winter
B) the bat enters a state of winter dormancy
D) when there is danger, the possum freezes
D) the shark has a torpedo-shaped body
E) bright coloring of the dart frog

Answer

2. Establish a correspondence between the characteristics of organisms and types of adaptations: 1) behavioral, 2) morphological, 3) physiological. Write numbers 1-3 in the order corresponding to the letters.
A) gnarled stick insect shape
B) freezing when there is danger in an opossum
C) crystals of potassium oxalate on the hairs of leaves and shoots of stinging nettle
D) brooding of eggs in the mouth by tilapia
D) bright colors of dart frogs
E) removal of excess water through the kidneys in the form of weakly concentrated urine by crayfish

Answer

Choose one, the most correct option. Which characteristic of the Sundew rotundifolia species should be considered a physiological criterion?
1) flowers are regular, white, collected in an inflorescence raceme
2) uses insect proteins as food
3) distributed in peat bogs
4) the leaves form a basal rosette

Answer

Choose one, the most correct option. Find the name of the type criterion in the specified list
1) cytological
2) hybridological
3) genetic
4) population

Answer

1. Select three sentences from the text that describe the ecological criterion of the species. Write down the numbers under which they are indicated in the table. (1) Housefly is a two-winged insect that serves as food for insectivorous birds . (2) Its mouthparts are of the licking type. (3) Adult flies and their larvae feed on semi-liquid food. (4) Female flies lay eggs on rotting organic matter. (5) Larvae white

Answer

, have no legs, grow quickly and turn into red-brown pupae. (6) An adult fly develops from the pupa. 2. Read the text. Select three sentences that describe the ecological criterion of the plant species Bladderweed. In your answer, write down the numbers under which they are indicated., sit 5-10 on a peduncle. (6) Common bladderwort is an insectivorous plant.

Answer

3. Read the text. Select three sentences that describe the ecological criteria of the house mouse species. Write down the numbers under which they are indicated in the table. (1) House mouse

Answer

- a mammal of the Mouse genus. (2) Original range - North Africa, tropics and subtropics of Eurasia. (3) Settles mainly near human habitation. (4) Leads a nocturnal and twilight lifestyle. (5) A litter usually produces 5 to 7 babies. (6) Under natural conditions it feeds on seeds. 4. Read the text. Select three sentences that describe the ecological criteria of the fieldfare species. Write down the numbers under which the selected statements are indicated.(1) The Field Thrush is a large bird. (2) Blackbirds live in

Answer

middle lane Russia. (3) Fieldfare thrushes settle along forest edges, in city squares and parks. (4) They feed on the ground, looking for earthworms, slugs and insects under dry leaves and in moss. (5) In winter they feed on the fruits of rowan, hawthorn and other berries that ripen on the bushes. (6) Fieldfare thrushes nest in small colonies, which number from 2-3 to several dozen nests. 5. Read the text. Select three sentences that describe the ecological criteria of the African ostrich species. Write down the numbers under which the selected statements are indicated. (1) African ostrich - large plica weighing up to 90 kg and height up to 3 m. (2) Lives in open savannas and semi-deserts, north and south of the zone

Answer

equatorial forests. (3) The beak is straight, flat, with a horny “claw” on the upper beak, the eyes are large - the largest among land animals, with thick eyelashes on the upper eyelid. (4) The legs are powerful, two-toed, the plumage is loose, the beards of the feathers do not adhere to each other and do not form feather plates. (5) The usual food is plants - shoots, flowers, seeds, fruits, but on occasion it also eats small animals - insects (locusts), reptiles, rodents and leftovers from predators' meals. (6) African ostrich can long time. (3) In spring and summer, the butterfly lays eggs on the leaves of cabbage or other cruciferous plants. (4) The eggs hatch into yellow caterpillars that feed on plant leaves. (5) As the caterpillars grow, they acquire a bright blue-green color. (6) The grown caterpillar crawls onto a tree and turns into a pupa, which overwinters.

Answer

7. Read the text. Select three sentences that describe the ecological criterion of the species Blue Cornflower (sowing). Write down the numbers under which they are indicated. (1) Blue cornflower is a weed plant of the Asteraceae family, found in the fields of grain crops. (2) The plant often lives along roads, near forest belts. (3) The erect stem of cornflower reaches up to 100 cm in height. (4) The flowers are bright blue. (5) Blue cornflower is a light-loving plant. (6) Flowers contain essential oils

Answer

, tannins and other substances. Choose one, the most correct option. Apply to description of animal species ecological criterion
- this means to characterize
1) variability of signs within the reaction norm
2) a set of external signs
3) the size of its range

Answer

4) a set of proposed feeds

Answer

1. Read the text. Select three sentences that describe the morphological criterion of the rhinoceros beetle species. Write down the numbers under which they are indicated.

Answer

3. Read the text. Select three sentences that describe the morphological criterion of the species of speedwell. Write down the numbers under which the selected statements are indicated. (1) Veronica oak grows in forest glades, meadows, and hillsides. (2) The plant has a creeping rhizome and a stem 10-40 cm tall. (3) Leaves with serrated edges. (4) Veronica oak grove blooms from late May to August. (5) Veronica is pollinated by bees and flies. (6) The flowers are small, of blue color

Answer

, collected in an inflorescence raceme.

Answer

4. Read the text. Select three sentences that describe the morphological criterion of the species Field Sparrow. Write down the numbers under which they are indicated.

Answer

2. Read the text. Select three sentences that describe the genetic criterion for the animal species Black Rat. Write down the numbers under which they are indicated. (1) It has been established that two species are hidden under the name “black rat”: rats with 38 and 42 chromosomes. (2) The black rat lives in Europe, most countries in Asia, Africa, America, Australia; Its distribution is not continuous, but is associated mainly with human dwellings in port cities. (3) The ranges of such species may overlap geographically, and in the same area, apparently indistinguishable individuals of black rats may live side by side without breeding. (4) Differences in the karyotype of different species provide isolation during interspecific crossings because they cause the death of gametes, zygotes, embryos or lead to the birth of infertile offspring. (5) In Europe, two races of the black rat are approximately equally common, one of which has a typical black-brown fur color, darker than that of the gray rat, and the other is almost brown-haired, with a white belly, similar in color to ground squirrels. (6) Studies of the number, shape, size and structure of chromosomes make it possible to reliably distinguish sibling species.

Answer

Choose two correct answers out of five and write down the numbers under which they are indicated. Which of the following is not a species criterion?
1) Genetic
2) Biocenotic
3) Cellular
4) Geographic
5) Morphological

Answer

1. Read the text. Select three sentences that describe the physiological criterion of the yellow ground squirrel species. Write down the numbers under which the selected statements are indicated.

Answer

2. Read the text. Select three sentences that describe the physiological criterion of the animal species Dread frog. Write down the numbers under which they are indicated. (1) One of the most poisonous vertebrates on Earth, these small tree frogs are found in a small area of southwestern Colombia, primarily in the lower layers of tropical rainforests. (2) They have bright, contrasting colors; males and females are of the same size. (3) The skin glands of the terrible poison dart frog secrete mucus containing a strong poison - batrachotoxin. (4) The poison protects the animal both from fungi and bacteria, and from natural enemies , which can become fatally poisoned if poison dart frog comes into contact with the skin or mucous membranes. (5) Dart frogs are diurnal; in nature they feed mainly on ants, other small insects

Answer

and ticks. (6) Animals are very active, and a hunger strike for 3-4 days can not only weaken a healthy, well-fed individual, but also cause its death. 3. Read the text. Select three sentences that describe the physiological criterion of the thermophilic bacterium Thiobacillus thermophilica. Write down the numbers under which they are indicated.(1) An ecologically separate group in nature is represented by thermophilic microorganisms that live in nature at temperatures from 40 to 93 degrees. (2) Hot springs North Caucasus, rich in hydrogen sulfide, are abundant in thermophilic species of thiobacteria, such as the thiobacterium Thiobacillus thermophilica. (3) This thermophilic bacterium is capable of dividing and developing at temperatures ranging from 40 to 70-83 degrees. (4) The membranes of thermophilic bacteria are characterized by high mechanical strength. (5) Thermophilic bacteria have enzymes that can function in high temperatures, providing the required speed chemical reactions in a cage. (6) Spores of thermophilic bacteria have significantly greater heat resistance than spores of mesophilic forms, and

Answer

4. Read the text. Select three sentences that describe the physiological criterion of the species Silver Poplar. Write down the numbers under which they are indicated. (1) Poplars grow very quickly and already reach their final height at the age of forty years. (2) The height of poplar trees ranges from 30 to 60 meters. (3) The plant does not live long, usually up to eighty years. (4) Poplar roots are thick, strong, and in many species they are located superficially. (5) Kidney cells form a sticky resinous substance. (6) The wood of the tree is soft and very light, the trunk is straight, the crown can have a variety of shapes.

Answer

2. Establish a correspondence between the characteristics and criteria of the species: 1) physiological, 2) environmental. Write numbers 1 and 2 in the order corresponding to the letters.
A) herbivory
B) pregnancy for one month
B) nocturnal lifestyle
D) the birth of several babies
D) high heart rate

Answer

1. Read the text. Select three sentences that describe the geographic criteria for the tuateria species. Write down the numbers under which they are indicated. (1) The only modern representative of the order Beak-headed reptiles. (2) Externally similar to a lizard, up to 75 cm long, along the back and tail there is a ridge of triangular scales. (3) Before the arrival of Europeans, they inhabited the North and South Islands of New Zealand. (4) At the end of the 19th century it was exterminated and preserved only on nearby islands in a special reserve. (5) Listed in the Red Book of the International Union for Conservation of Nature and natural resources

Answer

(IUCN). (6) Successfully bred at Sydney Zoo. 2. Read the text. Select three sentences that describe the geographical criterion of the plant species Siberian pine. Write down the numbers under which they are indicated.(1) Siberian cedar pine, or Siberian cedar- one of the species of the genus Pine; an evergreen tree reaching 35-44 m in height and 2 m in trunk diameter. (2) Cedar is very common in Western Siberia throughout the forest belt from 48 to 66 degrees N, and in Eastern Siberia frost-resistant, shade-tolerant, demanding of heat, air and soil humidity, avoids soils with close permafrost.

Answer

3. Read the text. Select three sentences that describe the geographical criterion of the animal species European grayling. Write down the numbers under which they are indicated. (1) European grayling is a freshwater fish of the grayling subfamily of the salmon family, weighing up to seven kilograms. (2) The life of these fish is associated with a certain water temperature, so grayling is not found in grassy areas, deep coastal bays and fiords. (3) This species of fish lives in the Bely and Baltic seas , in the Northern basin Arctic Ocean

Answer

, from Finland to the Tyumen region. (4) The rivers are inhabited by smaller graylings, barely weighing more than 1 kg. (5) Fish, making seasonal migrations in search of food, reach the upper reaches of the Dniester, Volga and Ural rivers. (6) Grayling is also found in the large northern lakes of the European part of Russia - Onega, Ladoga and some other reservoirs, in which it selects rocky, and less often, sandy shallows. 4. Read the text. Select three sentences that describe the geographical criterion of the animal species Song Thrush. Write down the numbers under which they are indicated.(1) The song thrush is a small songbird from the thrush family, native to Europe, Asia Minor and Siberia. (2) The song thrush colonizes Various types forests and are equally numerous in deciduous forests, and in the taiga. (3) Adult birds feed on invertebrates, song thrushes feed their chicks with various insects and small worms, and in the fall they eat various berries and fruits. (4) The habitat of the song thrush characterizes it as a northern, cold-resistant bird, choosing forests with young spruce shoots or juniper for nesting sites. (5) Actively populates the northern regions of the Scandinavian Peninsula and is numerous in the Eastern European forest-tundra, penetrating even into the tundra, and actively spreading to the east. (6) Not available in Southern Europe, on islands

Answer

1. Read the text. Select three sentences that describe the biochemical criterion of the species Stinging nettle. Write down the numbers under which they are indicated.

Answer

(1) Stinging nettle is a perennial herbaceous plant with powerful roots and a long horizontal branched rhizome. (2) Nettle is protected from being eaten by herbivores by stinging hairs that are located on all parts of the plant. (3) Each hair is a large cell. (4) The wall of the hair contains silicon salts, which make it brittle. (5) The content of formic acid in the cell sap of hairs does not exceed 1.34%. (6) Young nettle leaves contain many vitamins and are therefore used as food. 1. Match characteristic features
species of Nightshade and the criteria of the species to which they are classified: 1) morphological, 2) ecological, 3) biochemical. Write numbers 1-3 in the order corresponding to the letters.
A) Toxic substances are formed and accumulated in the plant.
B) Ripe berries contain a lot of sugar.
C) The berries are bright red in color.
D) The flowers are purple and have a regular shape.
D) Plants are common in vegetable gardens and river banks.

Answer

E) Plant height - 30-80 centimeters.
2. Establish a correspondence between the characteristics and criteria of the species Stinging nettle: 1) ecological, 2) morphological, 3) biochemical. Write numbers 1-3 in the order corresponding to the letters.
A) a perennial plant with a powerful root and a long rhizome
B) grows in forest clearings, in weedy places, along fences C) is formed in the leaves ascorbic acid
, carotene, vitamins B and K
D) nettle flowering continues from the beginning of summer until the beginning of autumn
E) flowers are small, unisexual, with a greenish perianth

Answer

E) potassium oxalate accumulates in leaf cells

individuals that are similar in morphophysiological characteristics are capable of interbreeding, producing fertile offspring, and forming a system of populations that form a common habitat. Each type of living organism can be described based on the totality characteristic features , properties called signs. Characteristics of a species by which one species is distinguished from another are called criteria

kind. The most commonly used are six general species criteria: morphological, physiological, geographical, environmental, genetic and biochemical. involves a description of the external (morphological) characteristics of individuals that are part of a certain species. By appearance, the size and color of the plumage can, for example, easily distinguish a great spotted woodpecker from a green one, a small spotted woodpecker from a yellow woodpecker, a great tit from a tufted tit, a long-tailed tit, a blue tit, and from a chickadee. Based on the appearance of the shoots and inflorescences, the size and arrangement of the leaves, the types of clover can be easily distinguished: meadow, creeping, lupine, mountain.

The morphological criterion is the most convenient and therefore widely used in taxonomy. However, this criterion is not sufficient to distinguish between species that have significant morphological similarities. To date, facts have accumulated indicating the existence of twin species that do not have noticeable morphological differences, but do not interbreed in nature due to the presence of different chromosome sets. Thus, under the name “black rat”, two twin species are distinguished: rats with 38 chromosomes in the karyotype and living throughout Europe, Africa, America, Australia, New Zealand, Asia west of India, and rats with 42 chromosomes. the spread of which is associated with the Mongoloid sedentary civilizations inhabiting Asia east of Burma. It has also been established that under the name “malaria mosquito” there are 15 outwardly indistinguishable species.

Physiological criterion lies in the similarity of life processes, primarily in the possibility of crossing between individuals of the same species with the formation of fertile offspring. Physiological isolation exists between different species. For example, in many species of Drosophila, the sperm of individuals of a foreign species causes an immunological reaction in the female genital tract, which leads to the death of sperm. At the same time, crossing is possible between some species of living organisms; in this case, fertile hybrids can be formed (finches, canaries, crows, hares, poplars, willows, etc.)

There are also species that have a discontinuous range. For example, linden grows in Europe and is found in the Kuznetsk Alatau and Krasnoyarsk Territory. The blue magpie has two parts of its range - Western European and Eastern Siberian. Due to these circumstances, the geographical criterion, like others, is not absolute.

Ecological criterion is based on the fact that each species can exist only under certain conditions, performing a corresponding function in a certain biogeocenosis. In other words, each species occupies a specific ecological niche. For example, acrid buttercup grows in floodplain meadows, creeping buttercup grows along the banks of rivers and ditches, and burning buttercup grows in wetlands. There are, however, species that do not have a strict ecological association. Firstly, these are synanthropic species. Secondly, these are species that are under human care: indoor and cultivated plants, pets.

Genetic (cytomorphological) criterion based on the difference between species by karyotypes, i.e., by the number, shape and size of chromosomes. The vast majority of species are characterized by a strictly defined karyotype. However, this criterion is not universal. First, many different species have the same number of chromosomes and their shape is similar. Thus, many species from the legume family have 22 chromosomes (2n = 22). Secondly, within the same species there may be individuals with different numbers chromosomes, which is the result of genomic mutations. For example, goat willow has a diploid (38) and tetraploid (76) number of chromosomes. In silver crucian carp, there are populations with a set of chromosomes of 100, 150,200, while their normal number is 50. Thus, in the case of the occurrence of polyploid or aneushyoid (the absence of one chromosome or the appearance of an extra one in the genome) forms, based on genetic criteria, it is impossible to reliably determine whether individuals belong to specific type.

Biochemical criterion allows you to distinguish species by biochemical parameters (composition and structure of certain proteins, nucleic acids and other substances). It is known that the synthesis of certain high-molecular substances is characteristic only of certain groups of species. For example, plant species differ in their ability to form and accumulate alkaloids within the families Solanaceae, Asteraceae, Liliaceae, and Orchids. Or, for example, for two species of butterflies from the genus Amata, a diagnostic sign is the presence of two enzymes - phosphoglucomutase and esterase-5. However, this criterion does not find wide application- it is labor-intensive and far from universal. There is significant intraspecific variability in almost all biochemical parameters, down to the sequence of amino acids in protein molecules and nucleotides in individual sections of DNA.

Thus, none of the criteria alone can serve to determine the species. A species can only be characterized by their totality.

Source : ON THE. Lemeza L.V. Kamlyuk N.D. Lisov "A manual on biology for those entering universities"