Physiological and ecological criteria of the species. Ecological criterion of a species: examples and concept

The belonging of individuals to a particular species is determined based on a number of criteria.

Type criteria- these are various taxonomic (diagnostic) characters that are characteristic of one species, but absent in other species. A set of characteristics by which one species can be reliably distinguished from other species is called a species radical (N.I. Vavilov).

Species criteria are divided into basic (which are used for almost all species) and additional (which are difficult to use for all species).

Basic criteria of the type

1. Morphological criterion of the species. Based on existence morphological features, characteristic of one species, but absent in other species.

For example: in the common viper, the nostril is located in the center of the nasal shield, and in all other vipers (nosed, Asia Minor, steppe, Caucasian, viper) the nostril is shifted to the edge of the nasal shield.

Twin species. Thus, closely related species may differ in subtle characteristics. There are twin species that are so similar that it is very difficult to use a morphological criterion to distinguish them. For example, the malaria mosquito species is actually represented by nine very similar species. These species differ morphologically only in the structure of the reproductive structures (for example, the color of the eggs in some species is smooth gray, in others - with spots or stripes), in the number and branching of hairs on the limbs of the larvae, in the size and shape of the wing scales.

In animals, twin species are found among rodents, birds, many lower vertebrates (fish, amphibians, reptiles), many arthropods (crustaceans, mites, butterflies, dipterans, orthoptera, hymenoptera), mollusks, worms, coelenterates, sponges, etc.

Notes on sibling species (Mayr, 1968).

1. There is no clear distinction between common species(“morphospecies”) and twin species: simply in twin species, morphological differences are expressed to a minimal extent. Obviously, the formation of sibling species is subject to the same laws as speciation in general, and evolutionary changes in groups of sibling species occur at the same rate as in morphospecies.

2. Sibling species, when subjected to careful study, usually show differences in a number of small morphological characters (for example, male insects belonging to different species clearly differ in the structure of their copulatory organs).

3. Restructuring of the genotype (more precisely, the gene pool), leading to mutual reproductive isolation, is not necessarily accompanied by visible changes in morphology.

4. In animals, sibling species are more common if morphological differences have less impact on the formation of mating pairs (for example, if recognition uses smell or hearing); if animals rely more on vision (most birds), then twin species are less common.

5. The stability of the morphological similarity of twin species is due to the existence of certain mechanisms of morphogenetic homeostasis.

At the same time, there are significant individual morphological differences within species. For example, the common viper is represented by many color forms (black, gray, bluish, greenish, reddish and other shades). These characteristics cannot be used to distinguish species.

2. Geographical criterion. Based on the fact that each species occupies a certain territory (or water area) - geographical area. For example, in Europe, some species of malaria mosquito (genus Anopheles) inhabit the Mediterranean, others - the mountains of Europe, Northern Europe, Southern Europe.

However, the geographical criterion is not always applicable. Habitats different types can overlap, and then one type smoothly passes into another. In this case, a chain of vicariating species is formed (superspecies, or series), the boundaries between which can often be established only through special research (for example, herring gull, black-billed gull, western gull, Californian gull).

3. Ecological criterion. It is based on the fact that two species cannot occupy the same ecological niche. Consequently, each species is characterized by its own relationship with its environment.

For animals, instead of the concept of “ecological niche,” the concept of “adaptive zone” is often used. For plants, the concept of “edapho-phytocenotic area” is often used.

Adaptive zone is a specific type of habitat with characteristic set specific environmental conditions, including the type of habitat (aquatic, land-air, soil, organism) and its particular characteristics (for example, in a land-air habitat - the total amount of solar radiation, precipitation, relief, atmospheric circulation, distribution of these factors according to seasons, etc.). In the biogeographical aspect, adaptive zones correspond to the largest divisions of the biosphere - biomes, which are a collection of living organisms in combination with certain living conditions in vast landscape-geographical zones. However, different groups of organisms use environmental resources differently and adapt to them differently. Therefore, within the biome of the coniferous-deciduous forest zone temperate zone One can distinguish adaptive zones of large guarding predators (lynx), large overtaking predators (wolf), small tree-climbing predators (marten), small terrestrial predators (weasel), etc. Thus, the adaptive zone is ecological concept, occupying an intermediate position between habitat and ecological niche.

Edapho-phytocenotic area- this is a set of bioinert factors (primarily soil factors, which are an integral function of the mechanical composition of soils, topography, the nature of moisture, the influence of vegetation and microorganism activity) and biotic factors(primarily, a collection of plant species) of nature that constitute the immediate environment of the species of interest to us.

However, within the same species, different individuals can occupy different ecological niches. Groups of such individuals are called ecotypes. For example, one ecotype of Scots pine inhabits swamps (swamp pine), another - sand dunes, and a third - leveled areas of pine forest terraces.

A set of ecotypes that form a single genetic system (for example, capable of interbreeding with each other to form full-fledged offspring) is often called an ecospecies.

Additional type criteria

4. Physiological-biochemical criterion. Based on the fact that different species may differ in the amino acid composition of proteins. Based on this criterion, for example, some species of gulls are distinguished (herring, black-billed, western, Californian).

At the same time, within a species there is variability in the structure of many enzymes (protein polymorphism), and different species may have similar proteins.

5. Cytogenetic (karyotypic) criterion. It is based on the fact that each species is characterized by a certain karyotype - the number and shape of metaphase chromosomes. For example, everyone durum wheat There are 28 chromosomes in the diploid set, and 42 chromosomes are soft.

However, different species can have very similar karyotypes: for example, most species of the cat family have 2n=38. At the same time, chromosomal polymorphism can be observed within one species. For example, moose of Eurasian subspecies have 2n=68, and moose of North American species have 2n=70 (in the karyotype of North American moose there are 2 less metacentrics and 4 more acrocentrics). Some species have chromosomal races, for example, the black rat has 42 chromosomes (Asia, Mauritius), 40 chromosomes (Ceylon) and 38 chromosomes (Oceania).

6. Physiological and reproductive criterion. It is based on the fact that individuals of the same species can interbreed with each other to form fertile offspring similar to their parents, and individuals of different species living together do not interbreed, or their offspring are infertile.

However, it is known that interspecific hybridization is often common in nature: in many plants (for example, willow), a number of species of fish, amphibians, birds and mammals (for example, wolves and dogs). At the same time, within the same species there can be groups that are reproductively isolated from each other.

Pacific salmon (pink salmon, chum salmon, etc.) live for two years and spawn only before dying. Consequently, the descendants of individuals that spawned in 1990 will breed only in 1992, 1994, 1996 (“even” race), and the descendants of individuals that spawned in 1991 will breed only in 1993, 1995, 1997 (“even” race). odd" race). An “even” race cannot interbreed with an “odd” race.

7. Ethological criterion. Associated with interspecific differences in behavior in animals. In birds, song analysis is widely used to recognize species. Depending on the nature of the sounds produced, different types of insects differ. Different species of North American fireflies vary in the frequency and color of their light flashes.

8. Historical criterion. Based on the study of the history of a species or group of species. This criterion is complex in nature, since it includes comparative analysis modern ranges of species, analysis

Goals and objectives of the lesson: to form the concepts of “species”, “species criteria”, “population”; continue to develop skills in working with texts and tables; ability to analyze and draw conclusions.

During the classes

1. Organizational moment

Formulating the topic of the lesson. Setting lesson goals and objectives

2. Repetition of the material covered (establishing connections between previously studied material and the material of the new topic)

a) The concept of species by K. Linnaeus, J.B. Lamarck and C. Darwin (checking the correctness of answers on slides 2-4)

b) Who proposed the binary nomenclature for species?

c) What does a double title include? Give examples

Find in the textbook modern definition type (for checking step 5)

Why do you think the modern species definition is so difficult?

(avoid mistakes when determining whether individuals belong to the same species)

Teacher's addition: Linnaeus made a mistake in classifying the male and female mallard duck as different species, taking into account only external signs(sl. 6)

3.Learning new material

a) The teacher’s story about what a species is and what the criteria for a species are using a presentation; the concept of reproductive isolation, its causes and significance for the existence of the species is given (sl. 7-22)

Class assignment:

As you explain and view the video, fill in the resulting table

b) Watching a video fragment from the educational film “Type Criteria”, which provides specific examples of type criteria and their relativity.

V) Independent work students to make additions to the table after watching a video clip

d) Checking the basic concepts included in the table

e) Formulation of conclusions (sl. 23, 25)

4. Fastening (sl. 24-26)

5. The concept of “Population” (sl. 28-31)

6. Summing up the lesson, grading.

7. Homework: par 1.4.1, questions 1-5, table,

Additional questions for homework.

1. Two cultivated plants, barley and rye, have the same set of chromosomes (14), but do not interbreed and differ in appearance and chemical composition. Determine: a) Barley and rye should be classified as the same or different species. b) What criteria specified in the text should be followed?

2. Two breeds of rabbits have the same number of chromosomes (44), but do not interbreed. differ in appearance and timing of puberty. a) Should these breeds of rabbits be classified as the same or different species? b) What criteria specified in the text should be followed?

References.

1. Textbook "Biology" V.B. Zakharov, S.G. Mamontov, V.I. Sivoglazov 11th grade.
2. G.M. Murtazin "Tasks and exercises in general biology"
3. N.A. Lemez, L.V. Kamnyuk, N.D. Lisov "A manual on biology for applicants to universities"
4. Magazine "Courier Unesco" June 1982
5. Internet Photos

A species is a collection of individuals that are similar in terms of species criteria to such an extent that they can natural conditions 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.
• Environmental - a combination of factors external environment, necessary for the life of the 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 different quantities 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 sign honey bee 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 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 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.
C) Animals have mastered the aquatic 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) an adult worm lives in small intestine person
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
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 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) Larvae 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) The flowers are painted yellow, 5-10 per 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- 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.

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) The Field Thrush is a large bird. (2) Blackbirds live in 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.

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) African ostrich– a large bird weighing up to 90 kg and growing up to 3 m. (2) Lives in open savannas and semi-deserts, north and south of the equatorial forest zone. (3) The beak is straight, flat, with a horny “claw” on the 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) Regular food are plants - shoots, flowers, seeds, fruits, but on occasion it also eats small animals - insects (locusts), reptiles, rodents and leftovers from predators' meals. (6) The African ostrich can go without water for a long time, 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) 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 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 Far North, northeast and southwest Asia. (2) The Field Sparrow is somewhat smaller than the House Sparrow, but has a more slender body, a brown crown and black spots on its 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) Green leaves pines are needle-shaped and are located in twos on shortened shoots. (5) Elongated shoots are arranged in whorls that form once a year. (6) Pollen from the male cones is carried by the wind and lands on the 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) Human somatic cells 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 summer heat and hibernates in winter. (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 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 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 are 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 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 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

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 one modern representative order of 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, the Northern and Southern Islands 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 type of fish lives in the basins of the White and Baltic Seas, in the Arctic Ocean basin, 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 large northern lakes 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 colonizes Various types 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) Absent in Southern Europe, islands Mediterranean Sea, although there are biotopes suitable for song thrushes there.

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. (1) Stinging nettle – perennial herbaceous plant with a powerful root 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. Match characteristic features species Nightshade bittersweet 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.
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

© D.V. Pozdnyakov, 2009-2019

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 the most important characteristics 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 attributed to one species similar plants, reproducing their own kind from their seeds.

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 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, the developing real species is determined by historical development under the influence. 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 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 organic world generally.

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 species differs from another in its set 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.

View - an elementary structural unit in the system of living organisms, a qualitative stage in their evolution. This is a collection of individuals that have similarities in internal and external structure, biochemical and physiological functions, freely interbreeding and producing fertile offspring, adapted to certain living conditions, having a certain type of relationship with abiotic (inert) and biotic environment and occupying a certain area in nature - habitat.

The species differ from each other in many ways. The characteristics and properties characteristic of a species are called criteria. As can be seen from the definition, among the criteria there are: morphological, physiological, cytogenetic, environmental and geographical .

Ecological criterion or the ecological characteristic of a species is a set of environmental factors in which the species exists. The habitat is determined by a combination of factors (abiotic, biotic and anthropogenic) and elements affecting the species in its habitat.

Thanks to diversity environmental factors There is a natural distribution of species around the planet. Fluctuations in the intensity of environmental factors are manifested in the disappearance of some species from certain territories, changes in their density, fertility and mortality rates. Under the influence of environmental factors, such adaptive modifications as hibernation or summer hibernation, diapause.

Any individual or community experiences the simultaneous impact of many factors, but only some of them are vital - limiting . The absence of these factors or their concentration above or below critical levels makes it impossible for individuals of a certain species to master the environment.

Due to the presence of limiting environmental factors for everyone biological species There is an optimum and limits to endurance.

For example, oysters the best way develop in water with a salt concentration of 1.5 - 1.8%. When the salt concentration is reduced to 1.0%, more than 90% of the larvae die within two weeks, and at a concentration of 0.25%, the entire population dies in one week. Increasing the salt concentration above the optimum level also has an adverse effect on oysters.

The interrelationship of several environmental factors makes environmental conditions even more complex.

The ability of a species to master different environments habitat is expressed by the value of ecological valency, depending on which species are distinguished stenotopic or eurytopic .

Eurytopic species can be represented by several ecotypes - varieties adapted to survive in environments that differ in certain factors.

For example, the asteraceous plant yarrow forms lowland and mountain ecotypes; the same property is characteristic of many other plants, for example, St. John's wort.

Each individual of the species is associated with old and young generations, with predators or prey, food items, enters into competitive relationships with neighbors or is associated with mutual assistance. The existence of a species' range does not mean that all individuals of the species are able to move freely throughout its entire territory. The degree of mobility of individuals is expressed by the distance over which the animal can move or the distance over which the generative and vegetative parts of the plant can move and is called activity radius .

For example, for a snail it is several tens of meters, for a beaver - several hundred meters, for reindeer- several hundred meters.

As a result, organisms living in opposite parts of their range often have little chance of meeting, although their meeting and the likelihood of offspring still exist. This leads to the fact that individual individuals of a species, adapting to specific habitat conditions, are united into natural groups (aggregates) or populations.

For example, all the perches in a small lake or all the trees of the same species in a forest.

Until the end of the 18th century. There was a doctrine about monotypic form , i.e. it was believed that the species was homogeneous within itself. Currently, the generally accepted doctrine is polymorphic form , subdivided into subspecies within which populations are distinguished.