Characteristics of type criteria. Species and its ecological characteristics Ecological criterion of the species examples

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 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 seen as a consequence of creative action.

Lamarck proclaimed in his writings the position that in the nature of unchangeable systematic units 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, the developing real species is conditioned historical development under the influence of In accordance with Darwinian teaching, a comprehensive study of systematic units was carried out. Thus, a study was carried out of the morphological criterion of the species, as well as experimental, genetic research 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 a 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 of difference.

The genetic (cytogenetic) criterion of the species, along with others, is used to distinguish between elementary systematic groups, analysis of the state of the species. In this article we will consider the characteristics of the criterion, as well as the difficulties that a researcher applying it may encounter.

In different industries biological science the species is defined in its own way. From an evolutionary perspective, we can say that a species is a collection of individuals that have similarities external structure and internal organization, physiological and biochemical processes, capable of unlimited interbreeding, leaving fertile offspring and genetically isolated from similar groups.

A species can be represented by one or several populations and, accordingly, have an integral or dissected range (territory/habitat)

Type nomenclature

Each species has its own name. According to the rules of binary nomenclature, it consists of two words: a noun and an adjective. A noun is a generic name, and an adjective is a specific name. For example, in the name "Dandelion officinalis", the species "medicinal" is one of the representatives of plants of the genus "Dandelion".

Individuals of related species within the genus have some differences in appearance, physiology, and environmental preferences. But if they are too similar, then their species identity is determined by the genetic criterion of the species based on the analysis of karyotypes.

Why does a species need criteria?

Carl Linnaeus, the first to give modern names and who described many types of living organisms, considered them unchanged and non-variable. That is, all individuals correspond to a single species image, and any deviations from it are an error in the implementation of the species idea.

From the first half of the 19th century century, Charles Darwin and his followers substantiate a completely different concept of species. In accordance with it, the species is variable, heterogeneous and includes transitional forms. The constancy of a species is relative, it depends on the variability of conditions environment. The elementary unit of existence of a species is a population. It is reproductively isolated and meets the genetic criterion of the species.

Given the heterogeneity of individuals of the same species, it can be difficult for scientists to determine the species identity of organisms or distribute them between systematic groups.

Morphological and genetic criteria of a species, biochemical, physiological, geographical, ecological, behavioral (ethological) - all these are complexes of differences between species. They determine the isolation of systematic groups, their reproductive discreteness. And from them one can distinguish one species from another, establish the degree of their relationship and position in the biological system.

Characteristics of the genetic criterion of the species

The essence of this trait is that all individuals of the same species have the same karyotype.

A karyotype is a kind of chromosomal “passport” of an organism; it is determined by the number of chromosomes present in mature somatic cells of the body, their size and structural features:

chromosome arm length ratio;
the position of the centromeres in them;
the presence of secondary constrictions and satellites.

Individuals belonging to different species will not be able to interbreed. Even if it is possible to obtain offspring, as with a donkey and a horse, a tiger and a lion, then interspecific hybrids will not be fertile. This is explained by the fact that the halves of the genotype are not the same and conjugation between chromosomes cannot occur, so gametes are not formed.

In the photo: a mule is a sterile hybrid of a donkey and a mare.

Object of study - karyotype

The human karyotype is represented by 46 chromosomes. In most species studied, the number of individual DNA molecules in the nucleus that form chromosomes falls within the range of 12 - 50. But there are exceptions. The fruit fly Drosophila has 8 chromosomes in its cell nuclei, and the small representative of the Lepidoptera family Lysandra has a diploid chromosome set of 380.

An electron micrograph of condensed chromosomes, which allows one to evaluate their shape and size, reflects the karyotype. Analysis of the karyotype as part of the study of genetic criteria, as well as comparison of karyotypes with each other, helps determine the species identity of organisms.

When two species are as one

A common feature of type criteria is that they are not absolute. This means that using only one of them may not be sufficient for an accurate determination. Organisms that are externally indistinguishable from each other may turn out to be representatives different types. Here the genetic criterion comes to the aid of the morphological. Examples of doubles:

Today there are two known species of black rats, which were previously identified as one due to external identity.
There are at least 15 species of malaria mosquitoes, which are distinguishable only through cytogenetic analysis.
In North America, 17 species of crickets have been found that have genetic differences, but are phenotypically classified as a single species.
It is believed that among all bird species there are 5% duplicates, for identification of which a genetic criterion must be used.
Confusion in the taxonomy of mountain bovids has been cleared up thanks to karyological analysis. Three types of karyotypes have been identified (mouflons have 2n=54, argali and argali have 56, urials have 58 chromosomes each).

One species of black rat has 42 chromosomes, the karyotype of another is represented by 38 DNA molecules.

When one view is like two

For species groups with a large area of range and number of individuals, when there is geographic isolation within them or individuals have a wide ecological valency, the presence of individuals with different karyotypes. This phenomenon is another variant of exceptions in the genetic criteria of the species.

Examples of chromosomal and genomic polymorphism are common in fish:

in rainbow trout, the number of chromosomes varies from 58 to 64;
two karyomorphs, with 52 and 54 chromosomes, were found in White Sea herring;
with a diploid set of 50 chromosomes, representatives different populations silver crucian carp have 100 (tetraploids), 150 (hexaploids), 200 (octaploids) chromosomes.

Polyploid forms are found in both plants (goat willow) and insects (weevils). House mice and gerbils may have different quantities chromosomes not a multiple of the diploid set.

Doubles by karyotype

Representatives different classes and types, karyotypes with the same number of chromosomes may occur. There are much more such coincidences among representatives of the same families and genera:

Gorillas, orangutans and chimpanzees have a karyotype consisting of 48 chromosomes. The differences cannot be determined by appearance; here you need to compare the order of nucleotides.
There are minor differences in the karyotypes of the North American bison and the European bison. Both have 60 chromosomes in the diploid set. They will be classified as one species if analyzed only by genetic criteria.
Examples of genetic twins are also found among plants, especially within families. Among willows, it is even possible to obtain interspecific hybrids.

To identify subtle differences in genetic material in such species, it is necessary to determine the gene sequences and the order in which they are inserted.

Impact of mutations on criterion analysis

The number of chromosomes in a karyotype can be changed as a result of genomic mutations - aneuploidy or euploidy.

With aneuploidy, one or more additional chromosomes appear in the karyotype, and there may also be a number of chromosomes less than that of a full-fledged individual. The reason for this disorder is the nondisjunction of chromosomes at the stage of gamete formation.

The figure shows an example of aneuploidy in humans (Down syndrome).

Zygotes with a reduced number of chromosomes, as a rule, do not begin to fragment. And polysomic organisms (with “extra” chromosomes) may well turn out to be viable. In the case of trisomy (2n+1) or pentasomy (2n+3), an odd number of chromosomes will indicate an anomaly. Tetrasomy (2n+2) can lead to an actual error in determining the species based on genetic criteria.

Multiplication of the karyotype - polyploidy - can also mislead the researcher when the karyotype of the mutant represents the sum of several diploid sets of chromosomes.

Criterion Difficulty: Elusive DNA

The diameter of the DNA strand in the untwisted state is 2 nm. The genetic criterion determines the karyotype in the period preceding cell division, when thin DNA molecules are repeatedly helicalized (condensed) and form dense rod-shaped structures - chromosomes. The thickness of a chromosome is on average 700 nm.

School and university laboratories are usually equipped with microscopes with slight increase(from 8 to 100), it is not possible to consider the details of the karyotype in them. The resolution of a light microscope, in addition, allows you to see objects no less than half the length of the shortest light wave at any, even the highest magnification. The shortest length is for violet waves (400 nm). This means that the smallest object visible in a light microscope will be from 200 nm.

It turns out that the colored decondensed chromatin will appear as cloudy areas, and the chromosomes will be visible without detail. An electron microscope with a resolution of 0.5 nm allows you to clearly see and compare different karyotypes. Considering the thickness of filamentous DNA (2 nm), it will be clearly visible under such a device.

Cytogenetic criterion at school

For the reasons described above, the use of micropreparations in laboratory work based on the genetic criterion of a species is inappropriate. In assignments, you can use photographs of chromosomes obtained under an electron microscope. For convenience, in the photo, individual chromosomes are combined into homologous pairs and arranged in order. This diagram is called a karyogram.

Sample assignment for laboratory work

Exercise. Look at the given photographs of karyotypes, compare them and draw a conclusion about whether the individuals belong to one or two species.

Photos of karyotypes for comparison in laboratory work.

Working on a task. Calculate total chromosomes in each karyotype photo. If they match, compare them by appearance. If it is not a karyogram, among the chromosomes of average length, find the shortest and longest in both images, compare them by size and location of the centromeres. Draw a conclusion about the differences/similarities of karyotypes.

Answers to the task:

If the number, size and shape of chromosomes match, then the two individuals whose genetic material is presented for study belong to the same species.
If the number of chromosomes differs by a factor of two, and chromosomes of the same size and shape are found in both photographs, then most likely the individuals are representatives of the same species. These will be karyotypes of diploid and tetraploid forms.
If the number of chromosomes is not the same (differs by one or two), but in general the shape and size of the chromosomes of both karyotypes are the same, we are talking about normal and mutant forms of the same species (the phenomenon of aneuploidy).
If the number of chromosomes is different, as well as the discrepancy between the characteristics of size and shape, the criterion will classify the presented individuals as two different species.

The conclusion must indicate whether it is possible to determine the species identity of individuals based on the genetic criterion (and only it).

Answer: it is impossible, because any species criterion, including genetic, has exceptions and may give an erroneous determination result. Accuracy can only be guaranteed by applying a set of type criteria.

Species criteria determine how strongly the traits and properties are expressed that distinguish one species from another.

A species is considered to be a historically formed association of populations, where individuals are endowed with genetic conformity, morphological and physiological similarity, freedom of crossing and further reproduction, and reside in a certain area under special living conditions.

Genetic (genetic-reproductive) criterion of the species

Genetic connection is the initial reason for the external similarity of organisms and the primary characteristic for combining into a separate set of individuals.

Individuals within one species are characterized by a certain set of chromosomes, their quantitative value, size and external outline.

The cytogenetic criterion is the most important characteristic of the species. Due to the different sets of chromosomes, living organisms of different species adhere to special isolation in the production of offspring and are not able to interbreed.

The study of the shape and number of chromosomes is performed using the cytological method. Number of structural elements cell nucleus — distinguishing feature kind.

Morphological criterion of the species

According to the morphological method, individuals of the same species are combined according to similar shape and structure. By appearance black and white crow belong to different types.

Morphological characteristics are one of the main ones, but often not decisive. In nature there are collections of organisms that have common external features, but not interbreeding. They are sibling species.

An example is species of mosquitoes previously classified as malarial. They are distinguished by a dissimilar food base, which assigns individuals to different ecological niches.

Ecological criterion of the species

Involvement in the individual environment is fundamental principle ecological criterion.

One type of mosquito feeds on the blood of mammals, another on birds, and a third on reptiles. However, some insect communities serve as carriers of malaria, while others do not.

Accordingly, two different species cannot coexist within the same ecological niche, but different living organisms of the same species can live in dissimilar habitats. Groups of these homogeneous populations are called ecotypes.

Physiological (physiological-biochemical) criterion of the type

The physiological criterion is manifested in connection with the characteristics of the complex complex of vital functions of the organism and its individual systems. According to this classification, individuals are grouped together based on the similarity of their reproductive processes.

Organisms outside the same species are virtually incapable of interbreeding or produce infertile offspring. But there are individual representatives capable of reproduction and producing viable offspring.

Therefore, division into types, based only on physiological sign, wrong.

Geographic criterion of the species

The geographical criterion is based on identifying the distribution areas of individuals in certain territorial areas. But often the ranges of different species overlap or are disrupted, which calls into question the absolute application of the method.

Behavioral criterion of the species

The behavioral or ethological criterion characterizes interspecific differences in the behavior of individuals.

Bird songs or sounds made by insects are used to recognize certain types of animals. Important role plays behavior during mating, reproduction and the nature of caring for offspring.

Species criteria - table for biology lessons with examples

Criterion name	a brief description of	Examples	Relativity of criterion
Genetic	They are distinguished by a certain karyotype and the ability to interbreed, with the birth of fertile offspring	Humans have 46 chromosomes	In one species, individuals with varying amounts and the structure of chromosomes (individuals of a house mouse, weevil). Different kinds may have the same number of chromosomes (cabbage and radish have 18 chromosomes each, rye and barley have 14 each; wolves, jackals and coyotes have the same set of chromosomes).
Morphological	Similarity external forms and structures of organisms	Vipers (common, steppe, viper), pika birds (steppe and red). Amur tigers are distinguished by a similar structure, color, thick fur and large size.	Having two different morphological forms in one species (the presence of various colors in the common viper); the presence of doubles (malarial mosquitoes, wrinkled rose and rose hips, chamomile and field chamomile).
Ecological	A combination of environmental factors, existence within a certain ecological niche	Habitat grass frog serves land, and pond frogs - water. The habitat of bank swallows is burrows on gently sloping river banks, while the city swallow nests in the city, and the barn swallow lives in the countryside.	The same species of wolves lives in the forest-steppe and tundra zones; Scots pine grows in swamps, sand dunes and leveled areas of pine forest routes.
Physiological	The genetic independence of individuals is due to obvious physiological uniqueness and the inability of organisms belonging to different species to mate.	A wild Tarpan horse, crossing with a Przewalski's horse, produces infertile offspring, and when hybridizing a European roe deer and a Siberian roe deer, a fetus of too large size develops, leading to the death of the female during childbirth.	In nature, there are often interspecies hybrids that are adapted to life and produce offspring (mating of common wolves and dogs produces healthy, fertile offspring; poplar and willow are crossed; hybrids of a lion and a male tiger are tigers).
Geographical	A specific area of location within a single habitat.	The Amur tiger is common in the Primorsky and Khabarovsk Territories, Manchuria, and the Sumatran tiger is common on the island of Sumatra.	The presence of categories that live everywhere (red cockroach, peregrine falcon, house fly). Migratory birds are distinguished by their existence outside specific habitats. Within the same habitat - Mexico, there are various species groups of cacti.
Behavioral	Features of habits during the mating season (special sounds, characteristic rituals).	Sounds made by male songbirds, tail spreading by a male peacock.	Various separate populations of individuals with similar behavior are known.

Morphological characteristics of representatives of flora and fauna

common wolf

The genus of wolves consists of seven species and 17 subspecies belonging to the common or gray wolf (Canis lupus). The division into subspecies groups occurred due to different body proportions and hair color.

Morphological characteristics:

large sizes;
external resemblance to a dog, differences in a more sloping frontal part, elongated paws, lowered rear part of the body, straight tail and special hair structure;
dark gray stripe along the ridge, the crown of the head with dark markings, a characteristic “mask” on the muzzle;
The color is gray-brown, ocher-rust and fawn, the roots and ends of the hair are dark, the middle is light in color.

The geography of its habitat differs in the breadth of its range. It exists in flocks of 2 to 40 animals. It is distinguished by highly social development. They make various sounds that facilitate communication between individuals.

Wolf refers to typical predators, but the diet also contains plant foods.

The wolf is a monogamous animal, living in pairs from mating until the offspring grow up. Mating games last from January to March. Puberty in males it occurs from 2 to 3 years, in females - by 2 years.

Cactus

The numerous cactus family has approximately 2800 species and is divided into 3 subfamilies:

Peiresquiaceae cacti include deciduous representatives;
Opuntiaceae consist of flat cacti and are divided according to shape into 3 groups;
Cereus includes plants lacking leaves and glochidia.

Distinctive morphological characteristics:

the presence of an areola, represented by spines or hairs;
the unique structure of the fruit and flower, which is the tissue of the stem.

The habitat of cacti is North and South America.

Amur tiger

The Amur tiger differs from other tigers in geographical and morphological characteristics. Range: Far East and northern China.

TO external differences relate:

thick and long fur;
fewer stripes.

Which type criterion is the most accurate?

Determine the most clear boundaries between species groups is possible using the genetic method.

But in nature, complete genetic isolation cannot exist, therefore, to determine whether an organism belongs to a certain species category, it is necessary to use several different criteria.

The oldest species criterion

The oldest and most widespread method of describing new species is the morphological criterion, which systematizes individuals according to external similarity.

This method is also the least accurate due to the frequent significant differences between organisms of a certain species and the morphological similarity of different individuals.

Conclusion

Species criteria contribute to in-depth study, analysis and the most accurate systematization of organisms. There are more than a million described species on Earth and a large number of still unknown and unexplored species.

The study of species characteristics contributes to the understanding of the process of evolution on Earth.

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 sign snapping 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 between 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 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 characteristics of the type wild pig(boar) and the criterion of the species to which this characteristic is attributed: 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 are nocturnal.

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) Sexual maturity of individuals occurs at four to five years.

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
IN) 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 poison 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) The larvae are white, have no legs, grow quickly and turn into red-brown pupae. (6) An adult fly develops from the pupa.

Answer

2. Read the text. Select three sentences that describe the ecological criterion of the plant species Pemphigus vulgare. In your answer, write down the numbers under which they are indicated. (1) Pemphigus vulgaris is mainly found in the Mediterranean region of Europe and Africa. (2) Common bladderwort grows in ditches, ponds, standing and slow-flowing reservoirs, and swamps. (3) Plant leaves are dissected into numerous thread-like lobes, leaves and stems are equipped with vesicles. (4) Bladderwort blooms from June to September. (5) Flowers are colored yellow, 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) The house mouse is a mammal of the genus Mouse. (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.

Answer

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) Field Thrush – large bird. (2) Blackbirds live in middle lane Russia. (3) Fieldfare thrushes settle in 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.

Answer

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) The African ostrich is a large bird weighing up to 90 kg and growing up to 3 m. (2) It lives in open savannas and semi-deserts, north and south of the zone 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 does without water, obtaining moisture from the plants it eats, but on occasion it readily drinks and loves to swim.

Answer

6. Read the text. Select three sentences that describe the ecological criteria of the cabbage white butterfly species. Write down the numbers under which they are indicated. (1) The cabbage white butterfly has a powdery white color on the upper side of its wings. (2) There are dark spots on the front pair of wings. (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) The flowers contain essential oils, tannins and other substances.

Answer

Choose one, the most correct option. To apply an ecological criterion to the description of an animal species means to characterize
1) variability of signs within the normal range of reaction
2) a set of external signs
3) the size of its range
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. (1) The rhinoceros beetle lives in the European part of Russia. (2) His body is brown. (3) Sexual dimorphism is well expressed. (4) Rhinoceros beetle larvae develop in compost heaps. (5) Males have a horn on their head. (6) Beetles can fly into the light.

Answer

2. Read the text. Select three sentences that describe the morphological criterion of the bush cherry species. Write down the numbers under which the selected statements are indicated. (1) Bush cherry is a low shrub or small tree 3-6 m high. (2) The bark is brown, the leaves are elliptical, pointed. (3) Bush cherry is one of the ancestors of common cherry varieties. (4) Grows in Russia in the European part of the country and in the south of Western Siberia. (5) The flowers are white, collected 2-3 in an umbrella inflorescence. (6) Cherry blossoms in April-May, and the fruits ripen in early summer.

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, 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. (1) The field sparrow is distributed throughout Eurasia, excluding the Far North, northeast and southwest Asia. (2) The Field Sparrow is somewhat smaller than the House Sparrow, but has more slender body, brown crown and black spots on white cheeks. (3) Individuals of the species weigh approximately 20–25 g. (4) Sparrows nest along the edges of groves, in open forests, and parks. (5) The clutch usually consists of five to six eggs. (6) The eggs are white or grayish in color with numerous small dark specks.

Answer

5. Read the text. Select three sentences that describe the morphological criterion of the Scots pine species. Write down the numbers under which they are indicated.(1) Scots pine is a light-loving plant. (2) When its seed germinates, five to nine photosynthetic cotyledons appear. (3) Pine can grow on any soil. (4) The green leaves of the pine are needle-shaped and arranged in twos on short shoots. (5) Elongated shoots are arranged in whorls that form once a year. (6) Pollen from male cones is carried by the wind and lands on female cones where fertilization occurs.

Answer

1. Read the text. Select three sentences that describe the genetic criterion of the species. Write down the numbers under which they are indicated. (1) There are a number of criteria by which one species is distinguished from another. (2) Each species has its own specific karyotype. (3) An important feature of a species is its habitat. (4) In individuals of the same species, chromosomes have a similar structure. (5) Somatic cells humans have 46 chromosomes. (6) Most mammals are characterized by sexual dimorphism.

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 black rats 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. (1) The yellow gopher lives in desert, uncultivated lands. (2) The gopher feeds on the succulent parts of steppe grasses, plant bulbs and seeds. (3) It also eats insects: locusts, grasshoppers, beetles and caterpillars. (4) The female gives birth to an average of seven young. (5) During the summer heat and winter it hibernates. (6) During hibernation, the animal’s body temperature drops to 1-2 °C, the heart beats at a frequency of 5 beats per minute.

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 found in a small area of southwestern Colombia, mainly in the lower tiers of rainfall tropical forests. (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) Tree climbers lead daytime look life, in nature they feed mainly on ants, other small insects and mites. (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.

Answer

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) The hot springs of the 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 growing when temperature conditions 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 at high temperatures, providing the necessary speed chemical reactions in a cage. (6) Spores of thermophilic bacteria have significantly greater heat resistance than spores of mesophilic forms, and maximum speed colony growth occurs at an optimal temperature of 55-60 degrees.

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. Choose three sentences that describe geographical criterion type of hatteria. 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 International Union nature conservation and natural resources(IUCN). (6) Successfully bred at Sydney Zoo.

Answer

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 pine, or Siberian cedar, is 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 due to permafrost, the northern border of the range sharply deviates to the south. (3) In Siberia it prefers sandy and loamy soils, but can also grow on rocky substrates and sphagnum bogs. (4) In Central Altai, the upper limit of the distribution of cedar lies at an altitude of 1900-2000 m above sea level. (5) Siberian cedar also grows in Mongolia and Northern China. (6) Siberian cedar pine 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 - freshwater fish subfamily of grayling 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 basins of the White and Baltic seas, in the basin of the North Arctic Ocean, 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, less often sandy, shallows.

Answer

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 inhabits various types of forests and is equally numerous in both deciduous forests and 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 Mediterranean Sea, although there are biotopes suitable for song thrushes there.

Answer

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

Answer

1. Establish a correspondence between the characteristic features of the species Bittersweet nightshade and the criteria of the species to which they belong: 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.
E) Plant height - 30-80 centimeters.

Answer

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) ascorbic acid, carotene, vitamins B and K are formed in the leaves
D) nettle flowering continues from the beginning of summer until the beginning of autumn
E) flowers are small, unisexual, with a greenish perianth
E) potassium oxalate accumulates in leaf cells

Answer

Vertyanov S. Yu.

It is usually quite easy to distinguish supraspecific taxa, but clear delimitation of the species themselves encounters certain difficulties. Some species occupy geographically separated habitats (areas) and therefore do not interbreed, but produce fertile offspring under artificial conditions. Linneevskoe short definition species as a group of individuals that freely interbreed and produce fertile offspring, is not applicable to organisms that reproduce parthenogenetically or asexually(bacteria and unicellular animals, many higher plants), as well as extinct forms.

Totality distinctive features type is called its criterion.

The morphological criterion is based on the similarity of individuals of the same species in terms of a set of external and internal structure. The morphological criterion is one of the main ones, but in some cases morphological similarity is not enough. Malaria mosquito Previously, six non-crossing similar species were named, of which only one spreads malaria. There are so-called twin species. Two species of black rats, practically indistinguishable in appearance, live separately and do not interbreed. Males of many creatures, such as birds (bullfinches, pheasants), look little like females. Adult male and female threadtail eels are so dissimilar that scientists for half a century have placed them in different genera, and sometimes even in different families and suborders.

Physiological-biochemical criterion

It is based on the similarity of the life processes of individuals of the same species. Some species of rodents have the ability to hibernate, while others do not. Many closely related plant species differ in their ability to synthesize and accumulate certain substances. Biochemical analysis makes it possible to distinguish between types of single-celled organisms that do not reproduce sexually. bacilli anthrax, for example, produce proteins that are not found in other types of bacteria.

The capabilities of the physiological and biochemical criterion have limitations. Some proteins have not only species specificity, but also individual specificity. There are biochemical characteristics that are the same in representatives of not only different species, but even orders and types. Physiological processes can occur in a similar way in different species. Thus, the metabolic rate of some Arctic fish is the same as that of other fish species in the southern seas.

Genetic criterion

All individuals of the same species have a similar karyotype. Individuals of different species have different sets of chromosomes, cannot interbreed and live separately from each other in natural conditions. The two sibling species of black rats have different numbers of chromosomes - 38 and 42. The karyotypes of chimpanzees, gorillas and orangutans differ in the location of genes on homologous chromosomes. The differences between the karyotypes of bison and bison, which have 60 chromosomes in their diploid set, are similar. Differences in the genetic apparatus of some species can be even more subtle and consist, for example, in different patterns of turning on and off individual genes. The use of genetic criteria alone is sometimes insufficient. One species of weevil combines diploid, triploid and tetraploid forms, the house mouse also has different sets of chromosomes, and the human nuclear protein histone H1 gene differs from the homologous pea gene by only one nucleotide. In the genomes of plants, animals and humans, such variable DNA sequences have been found that they can be used to distinguish between brothers and sisters in humans.

Reproductive criterion

(Latin reproducere reproduce) is based on the ability of individuals of one species to produce fertile offspring. The behavior of individuals plays an important role in crossing - marriage ritual, species-specific sounds (birds singing, grasshoppers chirping). By the nature of their behavior, individuals recognize the mating partner of their species. Individuals of similar species may not interbreed due to mismatched mating behavior or mismatched breeding sites. So, females of one species of frogs spawn along the banks of rivers and lakes, and of another - in puddles. Similar species may not interbreed due to differences in mating seasons or timing of mating when living in different climatic conditions. Different terms Flowering in plants prevents cross-pollination and serves as a criterion for belonging to different species.

The reproductive criterion is closely related to genetic and physiological criteria. The viability of gametes depends on the feasibility of chromosome conjugation in meiosis, and therefore on the similarity or difference in the karyotypes of the crossing individuals. The difference in daily physiological activity (day or night lifestyle) sharply reduces the possibility of crossing.

Using only the reproductive criterion does not always make it possible to clearly distinguish between species. There are species that are clearly distinguishable by morphological criterion, but producing fertile offspring when crossed. Among birds, these are some species of canaries and finches; among plants, these are varieties of willows and poplars. A representative of the order of artiodactyls, the bison lives in the steppes and forest-steppes of North America and never meets under natural conditions with the bison that lives in the forests of Europe. In a zoo environment, these species produce fertile offspring. This is how the European bison population, which was practically exterminated during the world wars, was restored. Yaks and cattle, white and brown bears, wolves and dogs, sables and martens. In the plant kingdom, interspecific hybrids are even more common; among plants there are even intergeneric hybrids.

Ecological-geographical criterion

Most species occupy a certain territory (area) and ecological niche. Acrid buttercup grows in meadows and fields; in damper places, another species is common - creeping buttercup; along the banks of rivers and lakes - pungent buttercup. Similar species living in the same habitat may differ ecological niches- for example, if they eat different foods.

The use of the ecological-geographical criterion is limited by a number of reasons. The species' range may be discontinuous. The species range of the mountain hare is the islands of Iceland and Ireland, northern Great Britain, the Alps and northwestern Europe. Some species share the same range, such as two species of black rats. There are organisms that are distributed almost everywhere - many weeds, a number of insect pests and rodents.

The problem of identifying a species sometimes becomes complex. scientific problem and is solved using a set of criteria. Thus, a species is a collection of individuals occupying a certain area and possessing a single gene pool that ensures hereditary similarity of morphological, physiological, biochemical and genetic characteristics, in natural conditions interbreeding and producing fertile offspring.