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This part of the body has many variants of morphology, so it is quite difficult to talk about any absolute uniformity in its external structure.

Number of abdominal segments

In typical cases, it includes ten or eleven segments - “rings”, which are attached to each other and form the visceral section. The 11th segment is found only in bessiazhkovyh, bivostok and other primary wingless insects - the most primitive forms of insects. In highly developed species, the posterior segments are reduced or rolled into the body.

The number of abdominal segments also depends on the stage of development: they, as a rule, are present in the maximum possible number, while others have fewer.

In adults, they also often merge with each other and have uneven thickness, so those with a short abdomen and small body size are distinguished by the fact that on their visceral section the number of clearly distinguishable rings can be reduced to three. However, in most representatives of the insect class the average number of segments ranges from 5 to 8.

The first segment of the abdomen in Stalk-bellied (Hymenoptera) is called and merges with the posterior part of the thoracic region, and the second (in ants - both the second and the third) is transformed into a thin stalk. Thanks to this structure, the abdomen acquires greater mobility in relation to the insect, and it becomes more convenient for the insect to manipulate (bees) or inject injections (riders).

Segment structure

The cuticular rings of the visceral region have a structure reminiscent of the morphology. Each segment is divided into two parts in the shape of half rings - upper and lower. On the lateral sides of the body they are connected to each other using a thin elastic pleural membrane. (photo) The same movable structure is also found at the junctions of neighboring segments. This adaptation allows the abdomen to change quite significantly in size, stretching 2-5 times after eating or during maturation (in females).

Song insects - mayflies, cicadas - have air cavities in their abdomen. By stretching and contracting the pleural membranes, they pump and release air from the abdominal region, gaining the ability to reproduce characteristic sounds. And some, for example, worker ants of the genus Myrmecocystus, have special reserve organs within the abdomen, in which they accumulate food substrates in large quantities for feeding the inhabitants of the nest and for their own nutrition. Being “filled”, the abdomens of these ants look like transparent golden drops several times larger in size and; as needed, insects regurgitate food for their fellow tribesmen, and then replenish their supplies again.

Atypical abdominal shape

Abdomen shape

The shape of the abdomen can be very different, and its features mainly depend on the lifestyle: the better the insect flies, the more streamlined and correct form at its visceral department. In order not to provide resistance when moving in the air, all appendages on the abdomen (primarily hairs) grow in the direction from front to back.

In addition to being cylindrical, the abdomen can be spherical, flattened in the upper-inferior direction, club-shaped, triangular in cross-section, etc. In most beetles it is thickened in the middle and narrowed towards the end, while its bottom surface almost flat, and the top, underneath - convex.

In front, the abdominal section can directly pass into (butterflies), or be separated from it by a “stalk” (bumblebees) or a constriction, as in some ground beetles. In the posterior part, it most often tapers in a spindle-shaped manner, forming a rounded apex. However, for example, bark beetles are distinguished by a shortened, as if “chopped off” abdomen, shaped like a truncated cone. (photo)

Abdominal appendages in the form of modified limbs

and external formations of the abdomen

Based on their origin and purpose, all additional structures of the visceral region can be divided into three groups:

Due to the fact that various insects have different quantities abdominal segments, many appendages and organs do not have a “permanent” place and can be located in different parts of it. Most of them are located at the posterior end of the body.

() - holes closed by a thin membrane through which gas exchange occurs. They are located on each segment of the visceral section, on the sides, in the area of ​​​​the junction of the upper and lower semirings.

False legs

- reduced and modified limbs. They do not contain locomotor muscles and do not serve for movement in adults, but have a simplified structure and are actively used in true and false caterpillars. In addition, the body of insects at any stage of development may have reduced legs that do not perform functions or are generally presented in the form of outgrowths. For example, the caterpillar of the king walnut butterfly has a very unusual look: in addition to the main false ones, on each segment of its abdominal section there are several reduced branched pseudopods. (photo)

- articulated appendages located on the last segment of the abdomen in the form of a “tail”. There are two, rarely three, they come from a reduced 11th segment and can have different lengths: from almost invisible in a fly to very pronounced in a house cricket. Higher forms insects are deprived of these additions.

Genital appendages and organs

- components of the reproductive system, which are usually located on 8 or 9 segments. Conventionally, they are considered main part abdomen Moreover, sometimes the visceral segment on which they are located is separated into a separate genital segment. Accordingly, the rings lying in front of it are called pregenital, and behind them - postgenital.

Depending on the characteristics of morphology, in many insects the abdomen can acquire additional significance. In caterpillars that move on false legs, it is involved in the locomotor function. Special muscle bundles, responsible for increasing and decreasing body length, connect adjacent segments. Thus, by relaxing and tensing them “in rhythm” with walking, he accelerates his progress.

The movable connection of the abdomen with the chest and the presence of a modified one in the Stalked-bellied animals make it easier for them to protect themselves. The luminescent organs of fireflies and the resonating cavities of cicadas help them communicate and ensure safety, and with the help of the accumulation of nutrients, “honey barrel” ants are able to survive even in unfavorable conditions of deserts and semi-deserts.

1. Arthropods. General structure

This is the most numerous type of animal. It has three classes - crustaceans, arachnids and insects. Mastered all environments of life. Unites more than 1.5 million species. Arthropods are the top of the evolutionary branch of invertebrates. They began their development in the seas of the Cambrian period and became the first land animals capable of breathing atmospheric oxygen.

Arthropods are characterized by common characteristics:

1. The body is covered with chitin - a horny substance, sometimes impregnated with lime. Chitin forms the exoskeleton and performs protective functions.

2. The limbs have a segmented structure, connected to the body through joints, with one pair of legs located on each segment.

3. The body is segmented and divided into two or three sections.

4. The muscles are well developed and attached in the form of muscle bundles to the chitinous cover.

5. The circulatory system is not closed, there is a heart. Blood - hemolymph pours into the body cavity and washes internal organs.

6. There are respiratory organs - gills, trachea, lungs.

7. The nodal type nervous system is more advanced. There are complex compound eyes, antennae - organs of smell and touch, organs of hearing and balance.

8. The excretory system is more advanced than that of annelids.

9. Arthropods are mostly dioecious animals and reproduce by eggs.

2. Class crustaceans.

The class has about 20 thousand species. It includes crayfish, crabs, lobsters, daphnia, cyclops, woodlice, shrimp and many more. etc. They are mainly inhabitants of water, and their respiratory organs are gills.

Let's consider external structure crustaceans using the example of crayfish.

The body is divided into three sections: head, chest and abdomen. Head and chestmerge to formcephalothorax,covered with a common shell; There are two pairs of antennae and three pairs of jaws on the head. First pair -antennulesis located on the head, and the second pair -antennas -on the first segment of the body (long). On the chest there are three pairs of jaws and five walking legs, and the first pair of walking legs has powerful claws. On the abdomen, on each segment, there are also limbs - abdominal. The female holds the eggs with them.

Let's look at the internal structure.

Living in water, crayfish breathe through gills. They are located under the lateral edges of the cephalothoracic shield. The circulatory system is not closed, there is a heart. Crayfish feed on carrion, biting the body with claws; have a complex digestive system. The nervous system of crayfish is the same as that of all invertebrates. It is represented by the abdominal nerve chain, the peripharyngeal nerve ring, consisting of the subpharyngeal and suprapharyngeal nerve nodes. Cancer has a well-developed sense of smell and touch, has an organ of balance and stalked eyes, consisting of many simple eyes - facets, the number of which increases with age. Each eye sees only part of the object, but the whole image is formed. This vision is called “mosaic vision.”

Cancers dioecious animals. After internal fertilization, the female lays eggs. Development occurs withmetamorphosis -complex transformation. The larva molts several times as it grows, each time becoming more and more similar to the adult form.

Based on their structure, crayfish can be divided into two groups: lower crayfish and higher crayfish.

Lower crustaceans include more primitive animals - daphnia and cyclops. These are quite small creatures. They can be seen with a low magnification microscope. Udaphniathere are two-branched antennae, which are not only sensory organs, but also organs of movement. Daphnia feed on bacteria, algae and other small organisms.

U Cyclopsthere is a cephalothorax. The main organ of locomotion is the powerful antennules (the first pair of antennae). These small crustaceans (daphnia and cyclops) are food for fish and form zooplankton.

Higher crustaceans include:crayfish, crabs, lobsters, lobsters, shrimp.

U crabsfive pairs of legs extending from the powerful shell of the cephalothorax are clearly visible. The abdomen is shortened and flat. Many crabs and shrimp are of commercial importance.

Unlike crabs, lobsters and spiny lobsters have a long, well-developed abdomen. These crustaceans live in the seas and oceans and are also of commercial importance.

U hermit crabthe fleshy abdomen is covered only with a thin soft film. Therefore, he hides it in the empty shells of sea mollusks, causing the body to take the shape of a twisted shell cavity. When a crayfish grows after molting, it changes its shell to a more spacious one.

Almost all crustaceans are edible and have almost the same taste.

3. Arachnids.

About 60 thousand species are known.

Let's look at the external structure of spiders.

The body is divided into sections: the cephalothorax and abdomen are round in shape. Four pairs of legs extend from the cephalothorax, i.e. 8 pieces with claws. The legs are equipped with tactile hairs. There are no antennae on the cephalothorax, but there are tentacles,which serve as organs of touch. There are jaws - chelicerae, which serve for grasping and tearing food.

Internal structure.

Due to the terrestrial lifestyle, lungs and trachea are developed.

The circulatory system, like all arthropods, is not closed. The abdomen contains the heart and blood vessels.

The nervous system is the same: the ventral nerve cord and the peripharyngeal nerve ring. Spiders have simple eyes, so their vision is weak. There are many tactile hairs on the body and limbs, which are connected to nerve endings.

The upper jaws have sharp, curved ends where ducts openpoisonous glands. At the end of the abdomen there are arachnoid warts, to which ducts openarachnoid glands. They produce a thick liquid, which, when leaving the body, solidifies into a thin transparent thread - a web. The web is a trapping network and is used to capture prey. The spider approaches the entangled victim through its web and pierces it with its upper jaws, injecting poison and digestive juices. The venom kills the victim, and digestive enzymes begin to digest the victim. After some time, the spider sucks out the digested food. This type of digestion is called external.

The excretory organs are the Malpighian vessels - branching tubes that open into the intestines.

Dioecious. They reproduce by eggs, which they lay in a cocoon. The offspring are protected. The development of born spiders occurs gradually with numerous molts.

Most famouscross spiderwith a cross-shaped light spot on the back,house spider, silver spider, living in water. The silverback spider builds a “cocoon” from its web, which is filled with the air the animal needs to breathe underwater.

In the southern regions, in Ukraine and the Caucasus, there is a large spidertarantula.He lives in a hole that he digs in the ground, and the entrance to it is covered with cobwebs. Its bite is very painful.

A small black spider lives in the deserts and steppes of the southkarakurt(translated from Turkic means “black death”). The bite of this spider is extremely dangerous. Karakurt poison causes pain, convulsions, vomiting, and sometimes death. The bite of karakurt is fatal for camels and horses, but sheep calmly eat it along with grass.

Spiders are very useful animals that destroy many harmful insects. The venom of most spiders is not dangerous to humans.

Causes considerable harmflour(barn), cheese, grains And bulb mites. Scabies mite (up to 0.3 mm ) gnaws numerous passages under human skin, causing acute itching (scabies). The disease is contagious and is transmitted by shaking hands.

Taiga tick endures something difficult viral disease- encephalitis. When bitten, the virus enters the bloodstream, reaches the brain, causing inflammation, and in severe cases, death can occur.

Ticks are carriers of such dangerous diseases.

Scorpios - These are the oldest arachnids, at first glance they look more like crustaceans. They are descendants of an ancient group of crustacean scorpions that became extinct about 190 million years ago. They have a segmented abdomen, the body is covered with a thick chitinous covering, and on the cephalothorax there are claws very similar to the claws of a crayfish. But upon closer examination, you will notice that four pairs of legs extend from the cephalothorax, and the claws are a modified second pair of jaws. On the rear abdomen there is a pair of poisonous glands with a sting. The scorpion, grabbing its prey with its claws, bends its abdomen over its head and stings the victim. Scorpions are poisonous and pose a particular danger to humans tropical species. The stings of scorpions, which live in the Volga region and the Caucasus, are painful, but not fatal.

4. Class insects

The largest group among animals. It is believed that their number ranges from approximately 1.5 to 2 million. Insects have mastered all living environments: air, water, land, soil. Their evolution followed the path of adaptation to terrestrial existence.

Body structure.

The articulated body is covered with a chitinous covering and is divided into three sections: head, thorax and abdomen. They have three pairs of jointed limbs. Most adults have wings. On the head there is one pair of antennae (antennae) and three pairs of jaws, forming Various types horny apparatus. The oral apparatus consists of one pair of lower and upper jaws, lower and upper lips.

By structure oral apparatus insects can be divided into 4 groups:

licking or lapping,Bumblebees, bees, and wasps have organs that feed on liquid food - flower nectar.

Sucking organs characteristic of butterflies.

Piercing-sucking mouthparts have mosquitoes, bedbugs, aphids.

Due to in various ways life limbs of insects are:

- running(cockroach),

- burrowing(Medvedka),

- swimming(swimming beetle),

- jumping(grasshopper).

Internal structure:

· The nervous system of insects is well developed. The sense organs have reached a high level of organization: touch, smell, taste, sight, hearing. Complex compound eyes are especially well developed (up to 28 thousand facets in each). Insects see green-yellow, blue and ultraviolet rays. Many of them hear well, including ultrasound.

· The respiratory system of insects is represented by tracheas. The tracheal trunks, branching repeatedly in the body of the insect, openspiracle holes on the sides of the metathoracic and abdominal segments.

· The excretory organ, in addition to special tubes-outgrowths of the intestine, is alsofat body,where metabolic products are deposited.

Development of insects. All insects are dioecious animals. After internal fertilization, the female lays several dozen eggs. The female always lays eggs near the food that the larva will feed on: plant leaves, soil, water surface, sewage, meat, etc. After some time, the larva hatches from the egg, which actively feeds and grows. Depending on the type of larva and its development into an adult insect, it may undergo complete or incomplete transformation.

Upon complete transformation - During metamorphosis, development occurs in four stages: egg, larva, pupa, and adult insect (imago). The larva is completely different from the adult form, and is more reminiscent of an annelid worm. Its type of diet and habitat may completely differ from that of an adult insect. The larvae have a gnawing mouthpart, actively feed and grow, molting several times. When the larva reaches its maximum size, it freezes, becomes covered with a new chitinous shell or arachnoid cocoon and turns intochrysalis.At this stage, insects do not feed (sometimes for the whole winter). After some time, an adult form, an imago, appears from the pupa, with all the signs characteristic of an adult insect (wings, limbs, mouthparts).

Development with complete transformation is characteristic of evolutionarily younger orders. Evolutionarily more ancient insects are characterized by incomplete transformation.

With incomplete transformation Development occurs in three stages: egg, larva-imago. There is no pupal stage. The body shape of the larva resembles an adult insect, differing only in size and the absence of wings. As the larva grows, it molts several times before it reaches adult size. In insects with incomplete metamorphosis, eggs usually overwinter.

The class of insects is very diverse. It has more than 30 orders, differing from each other mainly in the structure of the wings, mouthparts and development.

The most widespread lower insects with incomplete metamorphosis arecockroaches, dragonflies, orthoptera (grasshoppers, locusts, crickets), hemiptera (bugs).

Higher insects with complete metamorphosis includeColeoptera (beetles), Lepidoptera (butterflies), Hymenoptera (bumblebees, wasps, bees, ants, riders), Diptera (flies, horseflies, mosquitoes). mimicry characteristic for unprotected individuals— imitation of protected individuals (wasp flies).

Insects may have chemical “weapons” of defense, like bombardier beetles, which can fire the end of their abdomen to form a cloud of smoke. Ants secrete large amounts of formic acid, which has a burning effect.

There are social insects: bees, ants, termites, forming large families - colonies in which responsibilities are clearly distributed and individuals are differentiated: queen (large female), drones (males), workers, or soldiers.

Thanks to their ability to move actively, insects have populated all living environments. They can be found in all natural areas.

Most insects have small sizes(up to 1-3 cm). This allows them to live in places inaccessible to other animals. Thanks to various adaptations, they successfully survive in the struggle for existence.

Insects are characterized by seasonal and daily activity and migration in space. For example, butterflies can be diurnal or nocturnal. Locusts are capable of moving over vast distances.

The behavior of insects consists of direct reactions to factors external environment, and also due to instincts - hereditary unconditional reflex activity. Instincts are highly complex and ensure the appropriateness of the insect’s behavior. For example, a bee, performing a certain “dance” (flight), shows the way to flowers with nectar. In the evening, the ants close the passages to the anthill and expel the alien individuals. Some ants grow fungal mycelium in anthills, cultivate aphids, and “milk” them, forcing them to secrete special sugary substances.

Others bring great benefits by destroying plant pests and promoting pollination. For example, parasites lay eggs in the larvae or adults of other insects, thereby exterminating many agricultural pests.

There are insects bred by humans: the silkworm, from whose cocoon silk fiber is obtained.Bees also serve people. Soil insects loosen the soil, promote its aeration and accumulation of organic matter. In general, insects are an important link in complex food chains and are an integral part of various biocenoses.

1) Segmented body, jointed limbs.
2) Chitinous cover.
3) The circulatory system is not closed, the heart tube is on the dorsal side.
4) Peripharyngeal nerve ring and ventral nerve cord.

Differences

1) Body parts: in crayfish and spiders - the cephalothorax and abdomen, in insects - the head, thorax and abdomen.

2) Legs: crayfish can have a different number (crayfish have 10), spiders have 8 (4 pairs), insects have 6 (3 pairs).

3) Wings found only in insects, 2 pairs, located on the chest.

4) Eyes: in crayfish they are complex, faceted (consisting of many simple eyes), in spiders they are simple, in insects they are simple and complex.

5) Mustache: crayfish have 2 pairs, spiders do not, insects have 1 pair.

6) Respiratory and circulatory systems:

• Crayfish breathe through gills, oxygen is carried from the gills to all organs of the body by blood, so the circulatory system is well developed
• Insects breathe through tracheas: thin tubes through which air reaches every cell of the body. Blood does not carry oxygen, so the circulatory system is poorly developed (blood carries nutrients, metabolic products, hormones, etc.)
• Spiders breathe with lungs and tracheas; the circulatory system is moderately developed.

7)Excretory system: metanephridia (green glands) and Malpighian vessels, in crayfish only metanephridia.

In all insects, development is indirect (with metamorphosis, with transformation). The transformation can be complete or incomplete.

• Complete: egg, larva, pupa, adult insect. Characteristic of butterflies (Lepidoptera), beetles (Coleoptera), mosquitoes and flies (Diptera), bees (Hymenoptera), etc.
• Incomplete: egg, larva, adult insect (no pupal stage). Characteristic of grasshoppers and locusts (orthoptera), bedbugs.

Choose the one that suits you best correct option. The grasshopper develops
1) indirect
2) with a doll
3) direct
4) with complete transformation

Answer

Choose one, the most correct option. What functions does the circulatory system of insects perform?
1) transports nutrients and harmful waste products
2) carries out the transfer of gases
3) delivers oxygen to cells
4) participates in metabolism and energy conversion in the cell

Answer

Establish the sequence of stages of development of cabbage whites
1) egg
2) doll
3) caterpillar
4) adult insect

Answer

1. Establish a correspondence between the animal’s characteristic and the class for which it is characteristic: 1) arachnids, 2) insects
A) preliminary digestion of food outside the body
B) division of the body into the cephalothorax and abdomen
C) eyes are simple, from two to eight pairs
D) the presence of one pair of antennae on the head
D) the presence of three pairs of limbs on the chest
E) eyes are compound, complex structure

Answer

2. Establish a correspondence between the animal’s characteristic and the class for which it is characteristic: 1) arachnids, 2) insects
A) the presence of a cephalothorax and abdomen
B) one pair of antennae
B) four pairs of walking legs
D) eyes are simple or absent
D) breathing only tracheal

Answer

3. Establish a correspondence between the characteristics and the animals for which they are characteristic: 1) spider, 2) insect
A) respiratory organs - only trachea
B) chelicerae are developed
B) excretory organ - fat body
D) three pairs of walking legs
D) the body is divided into three sections
E) four pairs of walking legs

Answer

4. Establish a correspondence between the structural features of arthropods and the class for which they are characteristic: 1) arachnids, 2) insects. Write numbers 1 and 2 in the order corresponding to the letters.
A) the body consists of a head, chest, abdomen
B) there are antennae
B) 3 pairs of walking legs
D) there are only simple eyes
D) most have wings
E) there are pulmonary sacs and trachea

Answer

5. Establish a correspondence between the characteristics and classes of arthropods: 1) Arachnids, 2) Insects. Write numbers 1 and 2 in the order corresponding to the letters.
A) respiratory organs - exclusively trachea
B) direct development for the majority
B) the presence of three pairs of limbs
D) blood does not tolerate gases
D) the body consists of a cephalothorax and abdomen
E) the presence of one pair of antennae

Answer

Choose one, the most correct option. Incomplete transformation is characteristic
1) Peacock butterfly
2) fire beetle
3) dragonfly-yoke
4) house fly

Answer

1. Match the insect and its type postembryonic development: 1) with incomplete transformation, 2) with complete transformation
A) Asian locust
B) cockchafer
B) cabbage whites
D) housefly
D) green grasshopper
E) honey bee

Answer

2. Establish a correspondence between the type of animal and the type of its postembryonic development: 1) with complete transformation, 2) with incomplete transformation. Write numbers 1 and 2 in the correct order.
A) desert locust
B) bread ground beetle
B) common mantis
D) honey bee
D) birch moth

Answer

3. Establish a correspondence between a representative of the class of insects and the type of its development: 1) with incomplete transformation, 2) with complete transformation. Write numbers 1 and 2 in the order corresponding to the letters.
A) locusts
B) stag beetle
B) cockroach
D) grasshopper
D) bed bug
E) cabbage butterfly

Answer

4. Establish a correspondence between the types of insects and the types of their development: 1) with complete transformation, 2) with incomplete transformation. Write numbers 1 and 2 in the order corresponding to the letters.
A) ground beetle
B) forest bug
B) green grasshopper
D) cockchafer
D) butterfly urticaria

Answer

5. Establish a correspondence between the types of insects and the types of their development: 1) with complete transformation, 2) with incomplete transformation. Write numbers 1 and 2 in the order corresponding to the letters.
A) swimming beetle
B) migratory locust

B) mole cricket
G) ladybug
D) dragonfly rocker
E) red ant

Answer

COLLECTING 6

D) gravedigger beetle

D) Colorado beetle
E) bug, harmful turtle

Establish a correspondence between the characteristic and the class of the type Arthropods: 1) Crustaceans, 2) Insects. Write numbers 1 and 2 in the correct order.
A) Cephalothorax and abdomen
B) Excretory system - antennal glands
B) Respiratory organs - trachea
D) Respiratory organs - gills
D) Three pairs of walking limbs
E) Head, chest and abdomen

Answer

Establish a correspondence between the characteristics and classes of arthropods to which it belongs: 1) crustaceans, 2) arachnids. Write numbers 1 and 2 in the correct order.
A) the presence of two pairs of antennae
B) regulation of insect numbers
B) the presence of four pairs of limbs
D) transmission of certain types of diseases dangerous to humans
D) external digestion
E) purification of reservoirs from organic residues

Answer

Read the text. It is known that Kamchatka crab is one of the most large species crustaceans, inhabitant of the Far Eastern seas. Using this information, select three statements from the text below that describe these characteristics of this organism. Write down the numbers under which they are indicated. (1) The crab breathes oxygen dissolved in water. (2) The muscles of the crab's limbs are used as food. (3) Crabs are eaten by humans. (4) The body parts of the crab are the cephalothorax and abdomen. (5) Poaching significantly reduces the crab population. (6) Males reach a carapace width of 23 cm, a leg span of 1.5 m, and a weight of 7 kg.

Answer

Choose three correct answers out of six and write down the numbers under which they are indicated. What signs are characteristic of the animal shown in the picture?
1) closed circulatory system
2) division of the body into head, chest and abdomen
3) ventral nerve cord
4) four pairs of legs
5) one pair of antennae
6) breathing using pulmonary sacs and tracheas

Answer

All but two of the characteristics below are used to describe the animal shown in the picture. Identify two terms that “drop out” from the general list and write down the numbers under which they are indicated.
1) five pairs of walking legs
2) the presence of two to twelve simple eyes
3) the presence of a green gland
4) the body consists of a cephalothorax and abdomen
5) the presence of an arachnoid gland

Answer

Choose three correct answers out of six and write down the numbers under which they are indicated. Indicate the signs characteristic of insects with incomplete metamorphosis:
1) three stages of development
2) external fertilization
3) the larva looks like an annelid worm
4) the larva is similar in external structure to the adult insect
5) the larval stage is followed by the pupal stage
6) the larva turns into an adult insect

Answer

Establish a correspondence between the classes of animals and their characteristics: 1) crustaceans, 2) insects. Write numbers 1 and 2 in the order corresponding to the letters.
A) respiratory organs - trachea
B) respiratory organs - gills
B) three pairs of walking legs
D) five pairs of walking legs
D) direct development
E) development with complete and incomplete transformation

Answer

All but two of the examples below belong to orders of insects with complete metamorphosis. Identify two examples that “fall out” from the general list and write down the numbers under which they are indicated.
1) Coleoptera
2) Hemiptera
3) Diptera
4) Orthoptera
5) Lepidoptera

Answer

Choose three correct answers out of six and write down the numbers under which they are indicated. What signs are characteristic of insects?
1) division of the body into cephalothorax and abdomen
2) division of the body into head, chest and abdomen
3) tracheal respiratory system
4) pulmonary respiratory system
5) four pairs of walking limbs
6) six walking limbs

Answer

Select three statements related to the difference between arachnids and insects.
1) They have an external chitinous skeleton that serves as a frame for the entire body.
2) Four pairs of simple eyes.
3) Open circulatory system.
4) There are Malpighian vessels.
5) Four pairs of walking legs.
6) The body consists of the abdomen and cephalothorax.

Answer

Choose one, the most correct option. Aromorphic changes in arthropods include the appearance
1) organs of vision and touch
2) closed circulatory system
3) limbs, consisting of sections
4) nervous system in the form of a chain

Answer

Establish a correspondence between the characteristics of animals and the classes: 1) Insects, 2) Crustaceans. Write numbers 1 and 2 in the correct order.
A) respiratory organs - trachea
B) three pairs of limbs
B) five pairs of walking legs
D) respiratory organs - gills
D) hard chitinous shell
E) excretory system - Malpighian vessels

Answer

Choose three options. What characteristics do crayfish, cross spiders and chafer in the phylum Arthropods?
1) identical structure of excretory organs
2) chitinous body cover
3) compound eyes
4) closed circulatory system
5) division of the body into sections
6) ventral nerve cord

Answer

Establish a correspondence between the animal and the class to which it belongs: 1) Arachnids, 2) Insects
A) honey bee
B) scorpio
B) red forest ant
D) malaria mosquito
D) taiga tick

Answer

Establish a correspondence between an arthropod animal and the class to which it belongs: 1) Crustaceans, 2) Arachnids, 3) Insects. Write the numbers 1, 2 and 3 in the correct order.
A) scorpio
B) cross spider
B) egg-eater
D) Kamchatka crab
D) Black Sea shrimp
E) bed bug

Answer

Match the examples with the classes of animals: 1) Arachnids, 2) Insects, 3) Crustaceans. Write numbers 1-3 in the order corresponding to the letters.
A) Kamchatka crab
B) bed bug
B) ladybug
D) cross spider
D) Black Sea shrimp
E) common mantis

Answer

Find three errors in the given text. Indicate the numbers of the proposals in which they are made.(1) Insects are dioecious animals. (2) Females lay fertilized eggs, from which larvae hatch. (3) In some insects, the larvae do not look like adults; this type of development is called development with incomplete transformation. (4) In development with incomplete transformation, an insect goes through the following phases: egg - larva - pupa - adult. (5) Different food larvae and adults reduces competition and promotes the survival of the species as a whole. (6) Representatives of orders of insects with incomplete transformation include grasshoppers, crickets, bedbugs, and mosquitoes. (7) Representatives of insect orders with complete transformation include butterflies, beetles, bees, and bumblebees.

Answer

Answer

Choose three correct answers out of six and write down the numbers under which they are indicated. What features of the organization contributed widespread insects on the planet?
1) development of the secondary body cavity
2) the presence of a nervous system with a nodal structure
3) high fertility
4) variety of mouthparts
5) the presence of stinging organs
6) the presence of wings

Answer

Choose three correct answers out of six and write down the numbers under which they are indicated. If an animal's heart has the structure shown in the figure, then this animal is characterized by
1) the presence of hemoglobin in red blood cells
2) pelvic kidneys
3) tubular nervous system
4) open circulatory system
5) branched tracheal tubes
6) indirect development

Answer

Match the characteristics with the organisms. Write numbers 1 and 2 in the order corresponding to the letters.
A) gill breathing
B) has two pairs of antennas
B) eyes are simple
D) has five pairs of walking legs
D) usually has arachnoid glands
E) walking legs do not have claws at the end

Answer

© D.V. Pozdnyakov, 2009-2019

Task 1. Do laboratory work.

Subject: "The external structure of an insect insect."

Goal of the work: study the external structure of insects using the example of a cockroach or a large beetle.

1. Make sure that the workplace has everything necessary to perform laboratory work.

2. Using the instructions given in paragraph 26 of the textbook, complete the laboratory work.

3. Fill out the table.

Task 2. Fill out the table.

Task 3. Color the internal organs of the insect (red - circulatory organs; yellow - organs of the nervous system; green - organs of the digestive system) and label them.

Complete 4. Complete the table.

Digestive system, digestion, type of nutrition: mouth, pharynx, esophagus, stomach, intestines. Extracellular digestion, oral cavity, pharynx, esophagus, crop, gastric stomach, midgut, hindgut, anusSense organsSense organs

Comparative characteristics of arachnids and insects
Comparable characteristic	Class
	Arachnids	Insects
Distribution and lifestyle	land and terrestrial arthropods	all habitats except seas and oceans
Body parts	cephalothorax and abdomen, no antennae, 2 pairs of mouth organs	head, chest, abdomen; 1 pair of compound eyes, 1 pair of antennae
Limbs: number, location, structure	4 pairs of walking legs	three pairs of legs or wings
Digestive system, digestion, type of nutrition	mouth, pharynx, esophagus, stomach, intestines. Extracellular digestion	mouth, oral cavity, pharynx, esophagus, crop, stomach, midgut, hindgut, anus
Respiratory system	lungs and trachea	trachea
Nervous system	cephalothoracic ganglion	large supraglottic node
Sense organs	well developed, there are several pairs of eyes	well developed
Reproduction and development	internal fertilization	dioecious insects

Task 5. Write down the numbers of the correct statements.

1. The class Insects includes all tracheal-breathing arthropods with three pairs of legs.

2. In all insects, the body consists of a head, chest and abdomen.

3. Insects have legs on their chest and abdomen.

4. Insects live not only on land, but also in water and soil.

5. Insects eat everything that contains organic matter. Some of them have even adapted to feed on wool, wood and beeswax.

6. Along with compound eyes, many good flying insects also have simple eyes.

7. Insect antennae are organs of smell.

8. Aquatic insects have developed gill respiration.

9. Excretory organs of insects - Malpighian vessels.

10. In insects, blood flows only through blood vessels.

Correct statements: 1, 2, 4, 5, 6, 7, 9.