It is known that environmental pollution primarily affects the stomatal apparatus of plants. The main functions of stomata are gas exchange and transpiration. Violation of the functions of these stomata can lead to the death of leaves, and, in general, to the death of the entire plant (Lykshitova, 2013). We counted the number of stomata on the leaf blades of the studied plant species in key areas in comparison with the control. Research data are shown in Fig.16.

Rice. 16 Number of stomata on leaf blades Ulmus pumila, Malus baccata, Syringa vulgaris per 1 mm І sheet area

The calculation of the number of stomata per unit area of the leaf blade in woody plants growing in urban conditions showed that, indeed, when approaching the highway, the number of stomata increases. The influence of atmospheric pollution disrupts the integrity of the stomatal cells, and the guard cells of the stomata lose their ability to regulate the width of the stomatal gap.

With constantly open stomatal slits, the consumption of moisture by the plant organism on physiological processes especially affects the intensity of transpiration.

A decrease in the total water content of tissues and an increase in the amount of bound water over the amount of free water may indicate the adaptation of plants to the conditions of the urban environment. As bioindicative indicators of the urban environment, one can use the morphobiological indicators of woody plants, the percentage of dust pollution, and the features of the fractional composition of water.

From the presented figure, it can be seen that in the control plot, the largest number of stomata is observed in the squat elm and is 138, in the apple tree -127, in the lilac -100. Under conditions of environmental pollution, the number of stomata on the leaf blades of all studied species increases sharply. This is a morphological adaptive adaptation to the survival of plants in conditions of atmospheric pollution. An increase in the number of stomata on leaf blades compensates for the decrease in leaf dispersion, as shown earlier. This is due to the fact that a decrease in the area of leaves leads to a reduction in the stomatal apparatus, therefore, an increase in the number of stomata with a decrease in the total area of leaf blades contributes to the preservation of the functions of gas exchange and transpiration of leaves. Data on the number of stomata correlate well with data on leaf dispersion. As mentioned earlier, the greatest decrease in leaf dispersion was observed in elm. Data on the number of stomata indicate that the decrease in the number of leaves per square meter in elm was compensated by a sharper increase in the number of stomata. So, on average, in three plots, the number of stomata in the squat elm increased by 321 in comparison with the reference plot, while in apple and lilac 175 and 106, respectively.

This indicates that the elm adapts well to adverse environmental conditions.

Thus, it can be noted that under the conditions of technogenic pollution of the atmosphere of the city of Ulan-Ude, both arboreal life forms (apple and elm) and shrubs (lilac) adapt quite well to atmospheric pollution. In all species, morphological mechanisms of adaptation are activated. In conditions of more severe dust pollution, tree forms can be recommended - apple and elm.

All-Russian Verification Work VPR Biology Grade 5 Option 2 All-Russian Verification Work

1.1. Consider the image.

Show with arrows in the figure and sign the organs of the linden: stem, leaf, bud, flower.

1.2. Which of the organs of linden: stem, leaf, bud, flower is a rudimentary escape?

1.3. The list below lists the functions of plant organs. All of them, with the exception of one, are performed by the stem. Write down the function that "falls out" of the general series. Explain your choice.

Supporting (carries leaves, flowers and fruits), mineral nutrition, conductive, vegetative reproduction.

2. In winter, black fruits - nuts - are noticeable on bare linden branches. Nuts hang in small clusters, each cluster has a wing. The wind blew, tore off several clusters along with wings, whirled and dropped one next to the tree, the other - away. Find in the list below and write down the name of this process.

Flowering, development, resettlement, fruiting. 3.

Describe the linden leaf according to the following plan: leaf type, leaf venation, leaf blade shape.

A. Sheet type

B. Leaf venation

B. The shape of the leaf blade

4. Linden has always been considered a valuable tree in Russia. Painted Khokhloma dishes and nesting dolls are made from it (A), and in the old days, shoes (B). Write down the parts of the plant that are used in each case.

BUT: _____________________
B: _____________________

The student looked at the cellular structure of the leaves of various plants under a microscope and made the following drawing. What in the drawing of the cell of the sheet did he designate with the letter B?

6. Insert the missing words from the proposed list into the text "Reproduction".

BREEDING

There are two forms of reproduction of living organisms. During ________ (A) reproduction, special cells are involved - ___________ (B). From two cells a new cell is formed - ___________ (B). The new organism combines the characteristics of both parents.

Word list:
1) sexual
2) gamete
3) asexual
4) zygote
5) germ
6) larva

Write in the table the selected numbers under the corresponding letters.
Answer:

A	B	AT

7. 7.1. Using the table "Number of stomata", answer the questions.

Which plant contains stomata only on the upper side of the leaf?
Which plant has the most stomata?
Which plant has approximately the same number of stomata on both leaf surfaces?

7.2. Below are images of the plants indicated in the table. Label each picture with the name of the corresponding plant.

A B C D:______________

7.3. These plants are used by man. Under each of the examples below, write the name of the corresponding plant that is of practical importance to humans.

A B C:______________

8.1. Read the text and do the task.

Which sentences of the text describe signs on the basis of which it can be concluded that the bustard is the heaviest migratory steppe bird in Russia? Write down the numbers of the selected proposals.

8.2. Read the text and do the task.

(1) The main habitats of bustards are steppes, forb meadows and winter fields. (2) The average weight of adult birds is 16 kg, sometimes even 25 kg. (3) Plumage color is red with black speckles, white below. (4) Bustard nests are arranged in winter fields right on the ground. (5) The bird's gait is unhurried, measured. (6) Some birds winter in Transcaucasia, but most fly away for the winter outside Russia

Make a description of the great egret according to the following plan.

A) In comparison with the bustard: larger/smaller.
B) The similarity between the bustard and the great egret is that they
C) Where does the great white heron live and what does it eat? (Give at least two examples.)

Answers

1.1.

1.2. The kidney is the organ of the plant, from which the shoot appears in the process of development.
Answer: Kidney.

1.3. The function that falls out of the logical series is mineral nutrition. Mineral nutrition is provided by the root.
2. pollination

4. A - wood, B - bast

5. cytoplasm.

7.1. water lily white; olive; oats.

7.2. A - oak, B - oats, C - olive, G - white water lily.

7.3. A - peas or potatoes, B - rice, C - corn.

8.2. The correct answer should contain a description / features for three points of the plan:
A) smaller
B) large migratory birds;
C) swamps, reservoirs; fish, frogs, mollusks, worms, small birds.

Hello, dear readers of the Skype biology tutor blog.

This page of my blog contains the first 200 questions Open bank of tasks FIPI OGE on the 3rd section "System, diversity and evolution of living nature".

To check your level of preparedness for the exam, answer the tests yourself, and then you can check your answers with my answers by ordering them.

In a flowering plant, the following organs are distinguished: root, stem, leaf, flower, fruit with seeds. Select the characteristics that correspond to the structural features of the flower as a plant organ according to the following plan: definition of the organ, growth of the organ, location of the growth point, main functions and participation of the organ in the nutrition of the plant.

A. Definition of a plant organ
1) a lateral vegetative organ, which, as a rule, has bilateral symmetry
2) a reproductive organ that develops with the growth of the ovary of the pistil after pollination
3) modified generative escape
4) axial vegetative aboveground organ that carries the kidneys
5) axial vegetative underground organ

B. Organ growth
1) growth of the organ continues throughout the life of the plant
2) the growth of the organ continues for a certain time, after which it stops

B. Location of points of growth
1) the organ is characterized by growth by the base
2) the organ is characterized by apical growth
3) the organ grows due to the division of all cells

D. Organ functions
1) provides photosynthesis, evaporation, gas exchange
2) connects the aboveground and underground parts of the plant
3) strengthens the plant in the soil
4) participates in pollination, fertilization, seed development
5) serves to preserve and distribute seeds

D. Participation of the organ in the nutrition of the plant
1) only stores nutrients
2) provides the plant with water with dissolved minerals
3) does not provide the plant with nutrients, but only uses them for its own growth
4) carries out the synthesis of organic substances from carbon dioxide and water
5) provides the movement of mineral and organic substances, and sometimes stores them

Answer: A B C D D

Number of eggs in clutch	Percentage of surviving chicks (in %)
1	100
2	95
3	90
4	83
5	80
6	53
7	40
8	35
9	32

1) What is the relationship between the number of eggs in a clutch and the proportion of surviving chicks?
2) What is the percentage of chicks that have flown out of the nest with a clutch size of 5?
3) How can one explain that there are a small number of eggs in the clutch of a starling?

1) fruit
2) inflorescence
3) flower
4) fruiting body

Which organ is missing in sharks and rays?
1) intestines
2) gills
3) gill slits
4) swim bladder

Establish a correspondence between the animal and the number of chambers of its heart: for each element of the first column, select the corresponding element from the second column.

ANIMAL
A) a whale
B) already
B) crocodile
D) sparrow
D) frog
E) triton

NUMBER OF HEART CHAMBER
1) four
2) three

1) formation of trachea and spiracles
2) the formation of a three-chambered heart, in the ventricle of which there is an incomplete septum
3) the development of cubs in the uterus of the female
4) development of the nervous system of the nodal type
5) the appearance of paired lungs Answer: 41523 Incorrectly designed test. The answer will look like this: 1 then 5, if the word “lungs” means only the lungs that appeared in vertebrates (not taking into account paired lung sacs or “lights” in arachnids). But maybe the authors-compilers had conceived the answer 5 (light arachnids) then 1.

A specialized organ of air nutrition of a plant is
1) green leaf
2) root crop
3) flower
4) fruit

Modern lobe-finned fish include
1) shark
2) stingray
3) sturgeon
4) coelacanth

What common property unites the two depicted anatomical formations? Both of them are

1) the roots of living plants
2) solid particles of soil
3) insect larvae
4) plant residues

In the table below, there is a relationship between the positions of the first and second columns.

What concept should be entered in place of the gap in this table?
1) pedicel
2) gametophyte
3) fruiting body
4) sprout

What mollusks lead a terrestrial lifestyle?
1) toothless
2) slugs
3) barley
4) squid

The tuber is a modified shoot, this proves the presence on the tuber
1) membranous scales
2) buds-eyes
3) fleshy and juicy scales
4) flat stem - bottom

What animal is shown in the picture?

1) green euglena
2) infusoria shoe
3) common amoeba
4) malarial plasmodium

The figure shows light and dark moth butterflies on a birch trunk. As part of the experiment, light and dark butterflies were released into an isolated area of a birch forest in a ratio of 1: 1. How will the ratio of the number of light and black butterflies change over several years if there was an unregulated emission of soot and burning particles by enterprises?

3) the ratio of light and dark butterflies will not change

In fact, the dark pine trunk is clearly visible in the figure (the characteristic structure of the bark, and not the alternation of white and dark areas on the birch trunk). But in any case, with prolonged pollution of the trunks with soot, dark-colored butterflies will be less noticeable for pecking by birds.

Establish a correspondence between the characteristic of the plant and the department for which it is characteristic: for each element of the first column, select the corresponding element from the second column.

PLANT SIGN
A) there is a germ in the development cycle
B) the sporangium on the plant looks like a box
C) a green thread grows from the spore - a pregrowth
D) there are no roots
D) sporangia are located on the underside of the leaf
E) have rhizomes

DEPARTMENT
1) Mossy
2) Ferns

In the table below, there is a relationship between the positions of the first and second columns.

What concept should be entered in place of the gap in this table?
1) swimming beetle
2) grape snail
3) toothless
4) triton

Establish the sequence of the ratio of systematic categories in plants, starting with the smallest. Write down the corresponding sequence of numbers in your answer.

1) genus Nightshade
2) plant kingdom
3) class Dipartite
4) Solanaceae family
5) Department of Angiosperms

In connection with the release of the first plants on land, they had
1) vegetative organs
2) seeds
3) disputes
4) gametes

Which of the following animals develops with transformation? Choose three correct answers from six and write down the numbers under which they are indicated in the table.
1) crested newt
2) lake frog
3) common toad
4) gigantic kangaroo
5) steppe turtle
6) Nile crocodile

Using the table "Some characteristics of the leaf blades of flowering plants", answer the following questions.
Table. Some characteristics of leaf blades of flowering plants

View	Square sheet surface, cm 2	Number of stomata
View	Square sheet surface, cm 2	Upper side of the sheet, 1 cm 2	The underside of the sheet, 1 cm 2
Cabbage	–	14 100	22 600
Corn	600– 1350	5200	6800
Sunflower	38	175	325
Wheat	13– 15	3300	1400
Beans	49	4000	28 100
Apple tree	18	0	29 400
Potato	–	5100	16 100
oats	12– 15	2500	2300

Note. (–) indicates no data.
1) Which of the following plants is characterized by the smallest leaf blade? Give two examples.
2) What features of the arrangement of stomata on a leaf are typical for dicotyledonous plants presented in the table?
3) What role do stomata play in plant cooling?

The ability of organisms to respond to changes in their environment is called
1) irritability
2) adaptation
3) regeneration
4) homeostasis

The trunk of a tree grows in thickness due to cell division
1) wood
2) cambium
3) bark
4) bast

Which of the proposed descriptions most accurately reflects this dependence? Insect growth throughout development occurs

3) jumps, periods of rest are replaced by a sharp increase
4) unevenly, so in the first days there is a sharp increase, which then becomes smooth

Plant tissues are groups of cells united by a common structure, function and origin. They make up the organs of a plant. Select the characteristics corresponding to the integumentary tissue of a woody plant according to the following plan: tissue function; features of the cellular structure of the tissue; location in the root, stem, leaf.

A. Function of plant tissue
1) protects the plant organism from adverse external influences
2) provides the conduction of nutrients throughout the plant body
3) provides plant growth, gives rise to all plant tissues
4) provides photosynthesis and mineral nutrition of the plant
5) stores nutrients

B. Features of the cellular structure of tissue
1) tissue cells of two types: elongated sieve tubes with holes in the transverse septa and tube-vessels with destroyed transverse septa
2) the tissue consists of a layer of living cells that secrete a waxy substance or several layers of dead cells that surround all parts of the plant organ from the outside

B. Location of tissue in the root
1) forms a growth point at the root
2) is located in the holding area
3) is located in the root bark

D. Location of tissue in the stem of a tree
1) is represented by cambium and is located between the bast and wood
2) is located in the cork part of the tree stem
3) represented by bast and wood fibers
4) represented by vessels of wood and sieve tubes of bast
5) located in the core

E. Location of tissue in a sheet
1) is located in the veins of the leaf
2) located in the pulp of the leaf, represented by columnar and spongy layers
3) represented by the skin of the leaf
4) located at the base
5) fabric for a normal sheet is not typical

Answer: A B C D D

In the table below, there is a relationship between the positions of the first and second columns.

What concept should be entered in place of the gap in this table?
1) lungs
2) intestines
3) gills
4) heart

Which trait is unique to mammals?
1) developed live birth
2) show concern for offspring
3) internal fertilization occurs
4) cubs are fed with milk

Consider a graph that shows the natural decline in the number of trunks per 1 hectare of land in the reserve. What is the main reason for the decline in the number of plants in a spruce forest?

1) interspecific struggle for existence
2) intraspecific struggle for existence
3) active human activity

Establish a sequence of complication of the organization of animals in the process of historical development of the organic world on Earth. Write down the corresponding sequence of numbers in your answer.

1) isolation of the brain
2) the formation of the internal skeleton
3) the appearance of warm-bloodedness
4) the appearance of two layers of body cells
5) development of the intestine with mouth and anus

The figure shows the flag shape of a pine growing on the seashore. What caused the development of such an unusual plant crown?

It is known that the common mole is a soil mammal that feeds on animal food. Using this information, select three statements from the list below that relate to the description of these features of this animal. Write in the table the numbers corresponding to the selected answers.
1) The body length of the animal is 18–26.5 cm, and the weight is 170–319 g.
2) Adult animals are quarrelsome, attack relatives who have fallen on their site and can bite them to death.
3) The offspring of moles are born blind, naked and helpless. At this time, the female feeds him with milk.
4) The nesting chamber is located at a depth of 1.5–2 meters.
5) Along the river valleys, the mole penetrates north to the middle taiga, and south to the typical steppes.
6) The mole feeds on earthworms, eats slugs, insects and their larvae in smaller quantities.

Which part of the stem carries water and minerals?
1) wood
2) cambium
3) bark
4) core

Which of the following molluscs is harmful to crop production?
1) naked slug
2) octopus
3) oyster
4) barley

1) mosses
2) green algae
3) brown algae
4) lichens

What organ of the bean seed performs the function of leaves during germination?
1) germinal root
2) endosperm
3) germinal stalk
4) cotyledons

What plants have underground shoots? Choose three correct answers from six and write down the numbers under which they are indicated in the table.
1) potatoes
2) strawberry
3) lily of the valley
4) plantain
5) bow
6) raspberries

The scientist has grown many gray and black moth butterflies in the laboratory. He released them in two areas: rural and urban. Gray butterflies were visible against the background of black tree trunks, and black butterflies were visible against the background of light trunks. Then the scientist himself caught butterflies. In addition, the scientist observed what color butterflies were most eaten by birds in different areas. The data of the experiment are presented in the table "The results of the experiment on the survival of butterflies of different colors." Using the table, answer the following questions.
Table. The results of the experiment on the survival of butterflies of different colors

terrain	Butterflies released and caught	Number of gray butterflies	Number of black butterflies
Uncontaminated (rural)	Released	469	473
	Caught by a scientist	30	120
	eaten by birds	26	335
polluted (urban)	Released	137	447
	Caught by a scientist	51	53
	eaten by birds	62	95

1) How many gray butterflies did the scientist release in the countryside, and how many in the city?
2) What butterflies were eaten more by birds in rural areas?
3) The reliability of which hypothesis did the scientist try to check by observing the capture of butterflies by birds?

Insert in the text "Arthropods" the missing terms from the proposed list, using digital designations for this. Write down the numbers of the selected answers in the text, and then enter the resulting sequence of numbers (in the text) into the table below.
arthropods
Arthropods are animals with __________ (A) bodies that have dense integuments from __________ (B) and jointed limbs on the outside. Unlike annelid worms, the body of most arthropods is subdivided into sections: the head, chest, or cephalothorax, and __________ (B). These include, for example, crayfish, __________ (G), spiders, flies, beetles. The phylum Arthropoda is the largest in terms of the number of animal species.

LIST OF TERMS:
1) ray symmetry
2) tail
3) shrimp
4) bilateral symmetry
5) gastropod
6) abdomen
7) chitin
8) fiber

In the table below, there is a relationship between the positions of the first and second columns.

What concept should be entered in place of the gap in this table?
1) jellyfish cornerot
2) lake frog
3) grape snail
4) malarial mosquito

What sign indicates the relationship of Archeopteryx with modern birds?
1) fingers with claws on the forelimbs
2) tarsus in the hind limbs
3) small teeth in the jaws
4) developed caudal spine

The development of new shoots in poplars after filing the top is due to the kidneys
1) apical
2) renewal
3) generative
4) sleeping

The absorption of food through the entire surface of the body occurs in
1) human roundworm
2) white planaria
3) bull tapeworm
4) liver fluke

The water needed for photosynthesis enters the leaves through
1) vacuoles
2) bast fibers
3) sieve tubes
4) vessels

In the table below, there is a relationship between the positions of the first and second columns.

What concept should be entered in place of the gap in this table?
1) lungs
2) heart
3) gills
4) skin

CHARACTERISTIC
A) movement is carried out with the help of fins
B) among the representatives of the class, the following ecological groups are distinguished: freshwater, anadromous, brackish, marine
C) have mastered the ground-air habitat
D) in most representatives, the skin is covered with scales
D) the skin of the representatives of the class is naked and covered with mucus
E) the heart has three chambers

ANIMAL CLASS
1) Bony fish
2) Amphibians

The main function of the root is
1) storage of nutrients
2) soil nutrition of plants
3) absorption of organic matter from the soil
4) oxidation of organic substances

Ch. Darwin attributed to the guiding driving force of evolution
1) hereditary variability
2) intraspecific struggle
3) interspecific struggle
4) natural selection

What role do the eyelids play in the life of terrestrial vertebrates?
1) provide three-dimensional vision
2) increase visual acuity
3) promote eye moisturizing
4) protect the eyes from changes in atmospheric pressure

1) the number of light butterflies will increase
2) the number of dark butterflies will increase
3) the number of light and dark butterflies will remain unchanged
4) dark butterflies will disappear completely

When using the depicted object in the evidence base for evolution, the scientist should use knowledge from the field

1) paleontology
2) physiology
3) biogeography
4) cytology

The appearance of what signs serves as a narrow adaptation of organisms to certain environmental conditions? Choose three correct answers from six and write down the numbers under which they are indicated in the table.
1) fetus in angiosperms
2) wings on maple fruits
3) burrowing limbs in a mole
4) spine in fish
5) four-chambered heart in mammals
6) masking coloration in a grasshopper

What sequence of stages of individual development is typical for the animal shown in the figure?
1) an egg is an adult insect
2) egg - larva - adult insect
3) egg - larva - pupa - adult insect
4) egg - pupa - larva - adult insect

The supply of oxygen to the body of the hydra occurs through
1) the entire surface of the body
2) breathing holes
3) gill slits
4) tentacle cells

The fruit of the solanaceous potato and tomato plants is called
1) tuber
2) root cone
3) root crop
4) berry

The main merit of Charles Darwin before science is
1) scientific explanation of the origin of life
2) creating a reflex theory
3) improvement of selection methods
4) explaining the reasons for the fitness of organisms

1) the occurrence of photosynthesis
2) development of seeds in cones
3) the occurrence of double fertilization
4) the emergence of heterotrophic organisms
5) the participation of oxygen in metabolic processes in cells

Using the table "Survival of starling chicks depending on the number of eggs in a clutch", answer the following questions.
Table. Survival of starling chicks depending on the number of eggs in the clutch

Number of eggs in clutch	Percentage of surviving chicks (in %)
1	100
2	95
3	90
4	83
5	80
6	53
7	40
8	35
9	32

1) What is the percentage of surviving chicks from a clutch that had 6 eggs?
2) What is the relationship between the number of eggs in a clutch and the proportion of surviving chicks?
3) From the data in the table it can be seen that the minimum proportion of surviving chicks can be up to 1/3. What are the three reasons for such a large proportion of dead chicks according to Charles Darwin?

What is characteristic of saprotrophic bacteria?
1) exist by feeding on the tissues of living organisms

3) use organic substances of the secretions of living organisms
Saprotrophic bacteria use not only organic substances secreted by other organisms, but also decompose animal corpses and plant remains.

What layer of a cross section of a woody stem is not visible to the naked eye?
1) bark
2) cambium
3) wood
4) core

Which animal first developed a thorax in evolution?
1) Amphibians
2) Reptiles
3) Birds
4) Mammals

What role does the mucus produced by the skin glands have in the life of amphibians? Choose three correct answers from six and write down the numbers under which they are indicated in the table.
1) dissolves oxygen
2) increases the surface of the skin
3) disinfects the skin
4) Protects from natural enemies
5) increases the speed of blood movement
6) promotes movement in the ground-air environment

Table. fish breeding

fish species	Number of eggs	Average diameter of eggs		in different reservoirs
Common pike	30 thousand	2.5–3 mm	34 years	5 years
norwegian herring	200 thousand	1.3mm	27 years	8 years
Baltic cod	10 million	1 mm	5–9 years old	3 years
Carp	1.5 million	1 mm	5–6 years	8 years
Stickleback three-spined	100– 1000	1.8mm	1 year	2 years
common mackerel	450 thousand	1.1mm	24 years	3 years

1) Which species of fish have the smallest diameter of eggs?
2) What pattern is observed between the fecundity of a species and the size of its eggs?
3) Which of the fish presented in the table has developed care for offspring? Prove your answer with the data in the table.

Which of the following fertilizers are classified as mineral fertilizers? Choose three correct answers from six and write down the numbers under which they are indicated in the table.
1) litter
2) superphosphate
3) ash
4) manure
5) peat
6) potassium sulfate

A progressive sign of flatworms in relation to coelenterates is
1) multicellular structure
2) three-layer body structure
3) ray symmetry of the body
4) free-living lifestyle

The supply of nutrients in a grain of wheat is in
1) germ
2) endosperm
3) seed coat
4) membranous pericarp

1) the appearance of the cortex in the cerebral hemispheres
2) formation of a chitinous cover
3) the emergence of ray symmetry of the body
4) development of the intestine with the mouth and anus
5) the appearance of jaws in the skull

Why, when picking mushrooms, the mushroom picker should not dig the soil around the fruiting body?
1) the mycelium of the fungus is destroyed
2) the root system of adjacent trees is damaged
3) soil fertility is disturbed
4) there is a massive death of soil insects

Preservation in nature of animals and plants with traits that are useful to them occurs in the process
1) variability
2) insulation
3) struggle for existence
4) natural selection

Consider a graph that shows the natural fluctuation over 90 years in the abundance of hares and lynxes. What is the main reason for the regular change in the number of lynxes?

1) change in the number of hares
2) infectious diseases
3) active human activity to shoot them
4) struggle with adverse environmental conditions

Establish a correspondence between the characteristic and the class of animals to which it corresponds: for each element of the first column, select the corresponding element from the second column.

CHARACTERISTIC
A) the circulatory system is represented by one circle of blood circulation
B) the heart is filled only with venous blood
C) the transformation of venous blood into arterial blood occurs in the gills
D) the circulatory system is represented by two circles of blood circulation
D) the heart contains both venous and arterial blood
E) the transformation of venous blood into arterial blood occurs in the lungs and skin

ANIMAL CLASS
1) Bony fish
2) Amphibians

The mycelium that entangles the roots of a plant is called
1) mycorrhiza
2) lichen
3) moldy
4) scion

1) head
2) abdomen
3) cephalothorax
4) chest

Which of the following refers to the results of evolution?
1) natural selection
2) struggle for existence
3) hereditary variability
4) adaptation of organisms to the environment

Reefs are special communities of marine organisms that form from
1) jellyfish
2) fish
3) corals
4) shellfish

Why is yeast used in bread making?
1) release oxygen
2) emit carbon dioxide
3) store energy
4) release energy

The higher spore plants are
1) common pine
2) kelp
3) white mushroom
4) bracken fern

The excretory system of the animal shown in the figure is shown

1) green glands
2) malpighian vessels
3) liver
4) paired kidneys

What animal has a stomach, the structure of which is shown in the figure?

1) dog
2) pig
3) cow
4) horse

Which plant cells transport organic matter from leaves?
1) vessels
2) sieve tubes
3) cells of the skin of the leaf
4) mechanical fibers

The germ of the bean seed, during germination, receives nutrients from
1) pericarp
2) soil
3) cotyledons
4) endosperm

What is the function of the skin cells of a leaf?
1) absorb water vapor from the atmosphere
2) protect the sheet from drying out
3) store water and organic matter
4) give the sheet strength and elasticity

Using the table "The number of stomata in some plants", answer the following questions.
Table. The number of stomata in some plants

1) How are the stomata located in most of the plants presented in the table?
2) Why is the number of stomata different in many plants? Give one explanation.
3) How does the number of stomata depend on the humidity of the plant habitat?

Potato tubers are formed on
1) lateral roots
2) adventitious roots
3) modified underground shoots - stolons
4) modified underground shoots - rhizomes

The sieve tubes of the woody stem are part of
1) wood
2) cambium
3) bark bast
4) cork bark

The merit of C. Darwin lies in the fact that he
1) recognized the variability of species
2) developed a modern classification of animals and plants
3) proved that acquired traits are inherited
4) created the doctrine of natural selection

With the help of what organelles do protozoa get rid of harmful metabolic products dissolved in water?
1) digestive vacuoles
2) contractile vacuoles
3) protrusions of the cytoplasm - pseudopods
4) oral cavity and cell pharynx

Mushrooms are classified as a separate kingdom because they
1) reproduce by spores
2) immobile heterotrophs
3) are not capable of photosynthesis
4) consist of cells that do not have nuclei

Which ecological group of birds feeds mainly on insects?
1) birds of the forest
2) birds of the steppes and deserts
3) open air birds
4) birds of marshes, fresh waters and coasts

What plants have bright single flowers? Choose three correct answers from six and write down the numbers under which they are indicated in the table.
1) field poppy
2) red clover
3) May lily of the valley
4) common narcissus
5) common dandelion
6) yellow tulip

By what process is it possible to observe the diversity of the depicted breeds of domestic chickens?

2) interspecific struggle
3) natural selection
4) artificial selection

Goiter as a modification of part of the esophagus is developed in birds that feed on
1) insects
2) plant seeds
3) juicy fruits of plants
4) small rodents

Move in a reactive way
1) marine single polyps
2) free-living flatworms
3) marine annelids
4) cephalopods

The driving forces of evolution are
1) adaptation of organisms to the environment
2) variety of organisms
3) struggle for existence
4) the formation of new species

Examine the insect growth versus time graph (the x-axis is time (days) and the y-axis is insect length (in cm)).

Which of the proposed descriptions most accurately reflects the process of insect growth in the interval from 26 to 32 days? During this period, the insect grows
1) smoothly, without visible jumps
2) very sharp all the time
3) jumps, the period of rest is replaced by a sharp increase
4) at first abruptly, and then the growth stops completely

LIST OF TERMS:
1) sunflower
2) unicellular
3) cyst
4) plasmodium
5) fluke
6) multicellular
7) mosquito
8) zygote

1) the appearance of the digestive system
2) the emergence of the circulatory system
3) the appearance of trachea and spiracles
4) development of unicellular heterotrophic organisms
5) the appearance in the body of two layers of cells

What part of the body of crayfish is indicated by the letter A in the figure?

1) tail
2) abdomen
3) cephalothorax
4) chest

What is the structure of the mycelium penicilla?
1) branching threads of the mycelium are separated by partitions into separate cells, plastids are absent
2) branching threads of the mycelium are separated by partitions into separate cells, there are plastids
3) one strongly expanded cell with many nuclei, there are plastids
4) one strongly expanded cell with many nuclei, plastids are absent

SIGN
A) some representatives in development have a pupal stage
B) the vast majority are predators
C) the body consists of the head, thorax and abdomen
D) can only eat liquid food
D) the number of walking legs - 4 pairs
E) simple and compound eyes can be located on the head

ANIMAL CLASS
1) Insects
2) Arachnids

What process makes it possible to observe the diversity of the depicted breeds of pigeons?

1) the fight against adverse environmental conditions
2) natural selection
3) artificial selection
4) intraspecific control

The bulb is a modified shoot, this proves the presence of
1) main root
2) buds-eyes
3) underground stolons
4) flat stem - bottom

Which factor does not affect seed germination?
1) water
2) warm
3) soil
4) air It would be better to formulate this question as : Which factor is not required for seed germination?

Using the table "Some parameters of animals and humans", answer the following questions.
Table Some parameters of animals and humans

1) Which of the ungulates listed in the table has the maximum running speed?
2) Does the running speed of an animal depend on body weight?
3) Between which of the given organisms there are relations "predator - prey"?

Insert the missing terms from the proposed list into the text "Annelled worms" using numerals for this. Write down the numbers of the selected answers in the text, and then enter the resulting sequence of numbers (in the text) into the table below.
RINGED WORMS
Annelids are animals that have a long __________ (A) body. They are like flatworms and roundworms - __________ (B) animals with __________ (C) body symmetry. Annelids have __________ (D) and more complex nervous system and sensory organs than other worms. Annelids live in the seas, fresh waters, soil.

LIST OF TERMS:
1) two-layer
2) jointed
3) circulatory system
4) double sided
5) non-segmented
6) three-layer
7) radial
8) respiratory system

What is the function of the cap of the fruiting body of the boletus?
1) serves to attract animals and humans
2) captures solar energy, providing photosynthesis
3) is a place of spore formation
4) provides air supply

In angiosperms, unlike gymnosperms,
1) an embryo is formed in the seed
2) the body is made up of organs and tissues
3) double fertilization is carried out
4) fertilization occurs without the participation of water

What structural feature is similar in modern reptiles and birds?
1) bones filled with air
2) dry skin, devoid of glands
3) tail section in the spine
4) small teeth in the jaws

The organ of a flowering plant designed to protect its seeds is
1) peel
2) bump
3) fruit
4) ovule

The main root develops from
1) lateral roots
2) germinal root
3) adventitious root
4) dormant kidneys

Establish a sequence of complication of the organization of organisms in the process of historical development of the organic world on Earth. Write down the corresponding sequence of numbers in your answer.

1) the appearance of rhizoids
2) the formation of seeds in fruits
3) the occurrence of photosynthesis
4) the formation of seeds in cones

1) fitness of organisms
2) natural selection
3) struggle for existence
4) heredity and variability

With the help of what organs does a free-living white planaria worm get rid of harmful metabolic products dissolved in water?
1) mouth and throat
2) skin and muscles
3) excretory tubules
4) intestines and anus

The formation of new species in nature occurs as a result of
1) regular seasonal changes in nature
2) age-related physiological changes in individuals
3) interactions of driving forces (factors) of evolution
4) human environmental activities

Establish a correspondence between the plant and the method of distribution of its fruits and seeds: for each element of the first column, select the corresponding element from the second column.

PLANT
A) birch
B) apple tree
B) a rose (in the original OGE test there was a mountain ash, maybe a rose = rosehip here)
D) poplar
D) sunflower
E) burdock

METHOD OF DISTRIBUTION OF FRUITS AND SEEDS
1) wind
2) animals

The figure shows a representative of one of the classes of angiosperms. Members of this class usually have

1) one cotyledon per seed
2) six tepals perianth
3) net venation of leaves
4) fibrous root system

What adaptations do plants have to make better use of light?
1) the presence of a wax coating on the skin of the leaf
2) pubescence of leaf blades
3) the presence of a large number of stomata on the upper skin of the leaf
4) arrangement of smaller leaves between larger leaves

What group of animals arose in the process of evolution later than the others?
1) arthropods
2) intestinal
3) roundworms
4) flatworms

Representatives of the chordate type, unlike other animals, have
1) three-layer structure
2) internal skeleton
3) body cavity
4) circulatory system

Examine the insect growth versus time graph (the x-axis is time (days) and the y-axis is insect length (in cm)).

Which of the proposed descriptions most accurately reflects the process of insect growth in the interval from 6 to 14 days? During this period, the insect
1) does not grow
2) grows very fast over time
3) grows spasmodically, periods of rest are replaced by a sharp increase
4) at first it grows sharply, and then its growth stops

Examine the insect growth versus time graph (the x-axis is time (days) and the y-axis is insect length (in cm)).

Which of the proposed descriptions most accurately reflects the process of insect growth in the interval from 32 to 40 days? Insect growth during this period
1) occurs smoothly, without visible jumps
2) slow down all the time
3) occurs abruptly, the rest period is replaced by a sharp increase
4) missing

Establish the sequence of appearance on Earth of the main groups of plants in the process of evolution. Write down the corresponding sequence of numbers in your answer.

1) psilophytes
2) unicellular green algae
3) multicellular green algae
4) ferns
5) gymnosperms

By what process can one observe the diversity of the depicted varieties of cabbage?

1) the fight against adverse environmental conditions
2) natural selection
3) artificial selection
4) intraspecific competition

In the table below, there is a relationship between the positions of the first and second columns.

What concept should be entered in place of the gap in this table?
1) hydra
2) toad
3) bee
4) toothless

Reindeer moss in its structure is attributed to
1) mushrooms
2) lichens
3) mossy
4) herbaceous plants

Root growth in length occurs due to cell division
1) root hairs
2) educational tissue
3) holding areas
4) root cap

What life form is most often found in monocotyledonous plants?
1) herbs
2) shrubs
3) shrubs
4) trees

In the table below, there is a relationship between the positions of the first and second columns.

What concept should be entered in place of the gap in this table?
1) leaflet
2) embryo
3) basket
4) seed

The digestive system is absent
1) human roundworm
2) white planaria
3) bull tapeworm
4) liver fluke

1) bull tapeworm
2) echinococcus
3) roundworm
4) liver fluke

In green mosses, unlike algae,
1) cells have large and small nuclei
2) fertilization occurs in the presence of water
3) the thallus is divided into tissues and organs
4) sexual and asexual reproduction is carried out

Rhizome - a modified shoot, this proves the presence on the rhizome
1) main root
2) membranous scales
3) flat stem - bottom
4) mechanical fibers

A representative of which department of the plant kingdom is shown in the figure?

On what basis are plants grouped into one family?
1) the same area
2) similar structure of flower and fruit
3) the same number of cotyledons in the seed
4) the presence of sexual and asexual methods of reproduction

With the death of marine shell rhizomes, the formation of
1) peat
2) granite
3) limestone
4) hard coal

Establish a correspondence between the trait and the class of animals for which it is characteristic: for each element of the first column, select the corresponding element from the second column.

SIGN
A) eggs are large, with a large amount of yolk
B) the heart is three-chambered and has an incomplete septum
C) the skin contains sweat and sebaceous glands
D) the body temperature of the representatives is unstable
D) well-developed care for offspring
E) common in northern latitudes

CLASS
1) Reptiles
2) Mammals

The appearance of what signs is an example of the narrow adaptation of organisms to certain environmental conditions? Choose three correct answers from six and write down the numbers under which they are indicated in the table.
1) chords in non-cranial
2) flowers in angiosperms
3) sharp fangs in wolves
4) mammary glands in mammals
5) pollination of wild rose flowers by insects
6) long main root of camel thorn
Answer:

Mammals descended from ancient
1) dinosaurs
2) animal-toothed lizards
3) lobe-finned fish
4) tailed amphibians

What number in the figure indicates the placenta?

1) 1
2) 2
3) 3
4) 4

Examine the insect growth versus time graph (the x-axis is time (days) and the y-axis is insect length (in cm)).

In what time interval is the maximum increase in the size of the insect's body observed?
1) 6-7th day
2) 14–15th day
3) 33–34th day
4) 40–41 day

Using the table "Reproduction of fish", answer the following questions.
Table fish breeding

fish species	Number of eggs	Average diameter of eggs	Average age of sexual maturity	Average age of fish caught in different reservoirs
Common pike	30 thousand	2.5–3 mm	34 years	5 years
norwegian herring	200 thousand	1.3mm	27 years	8 years
Baltic cod	10 million	1 mm	5–9 years old	3 years
Carp	1.5 million	1 mm	5–6 years	8 years
Stickleback three-spined	100– 1000	1.8mm	1 year	2 years

1) What is the range of average sizes of fish eggs presented in the table?
2) What kind of fish populations can be undermined by intensive fishing? Explain the answer.
3) Why, according to the theory of Charles Darwin, with such fecundity, the number of fish remains relatively constant?

What analyzer is used to orientate bats in space?
1) visual
2) olfactory
3) tactile
4) auditory

In the table below, there is a relationship between the positions of the first and second columns.

What concept should be entered in place of the gap in this table?
1) receptacle
2) pestle
3) stamen
4) whisk

Establish the sequence of the systematic position of the white hare species, starting with the smallest group. Write down the corresponding sequence of numbers in your answer.

1) detachment Lagomorphs
2) class Mammals
3) Hare family
4) genus Hares
5) type Chordates

Establish a correspondence between the plant and the type of its underground shoot: for each element of the first column, select the corresponding element from the second column.

PLANT
A) wheatgrass
B) lily
B) lily of the valley
D) daffodil
D) bought a pharmacy
E) common garlic

TYPE OF UNDERGROUND Escape
1) rhizome
2) bulb

K. Linnaeus, in his system of living nature, erroneously attributed the depicted animal to fish, but it should be correctly attributed to the class

1) Mammals
2) Amphibians
3) Cephalopods
4) Reptiles

The plant shown in the figure reproduces asexually by means of

1) seeds
2) gamete
3) dispute
4) hyphae

Which of the following appeared in the process of evolution in flatworms in comparison with coelenterates?
1) intestinal cavity
2) endoderm
3) circulatory system
4) third germ layer

Which ecological group does the bird shown in the picture belong to?

1) birds of open spaces
2) diurnal predators
3) nocturnal predators
4) insectivorous forest birds

The movement of dissolved minerals from the roots to the leaves in the plant body occurs through
1) vessels
2) sieve tubes
3) cambium cells
4) mechanical fibers

Insects breathe with
1) gill
2) trachea
3) lungs
4) lung bags

A flower that has both stamens and pistils is called
1) dioecious
2) bisexual
3) monoecious
4) dioecious

What are the characteristics of putrefactive bacteria?
1) use ready-made organic substances of living organisms
2) synthesize organic substances from inorganic ones using the energy of the sun
3) use organic matter of dead organisms
4) synthesize organic substances from inorganic ones, using the energy of chemical reactions

By what process can the variety of dog breeds depicted be observed?

1) the fight against adverse environmental conditions
2) natural selection
3) artificial selection
4) intraspecific control

Angiosperms include plants
1) Mossy
2) Ferns
3) Gymnosperms
4) Dicotyledons

Which trait is characteristic of plants of the class Dicotyledonous?
1) the number of petals in flowers is a multiple of 3
2) tap root system
3) arc venation of leaves
4) parallel venation of leaves

What does a freshwater hydra polyp eat?
1) bacteria
2) small crustaceans
3) unicellular animals
4) unicellular algae

1) Mossy
2) Ferns
3) Gymnosperms
4) Lycopsoid

What is characteristic of a bacterial cell?
1) the ring chromosome is located in the cytoplasm
2) the nucleus is separated from the cytoplasm by two membranes
3) transport of substances through the ER of the cell
4) oxidation and storage of energy in mitochondria

The figure shows the head of a frog. Which organ is labeled A in the figure?

1) eye with eyelid
2) eardrum
3) organ of touch
4) lateral line

A representative of which department of the plant kingdom is shown in the figure?

What does the infusoria-shoe eat?
1) bacteria
2) small crustaceans
3) insect larvae
4) unicellular animals

1) the appearance of the external skeleton
2) the appearance of a five-fingered limb
3) the emergence of the circulatory system
4) the development of cubs in the uterus of the female
5) the supply of oxygen through the entire surface of the body

Establish a sequence of subordination of systematic categories, starting with the smallest. Write down the corresponding sequence of numbers in your answer.

1) cruciferous family
2) Department of Angiosperms
3) genus Radish
4) class Dicotyledonous
5) plant kingdom

Representative of what type of animal kingdom is shown in the picture?

1) digestive
2) nervous
3) respiratory
4) muscular

What are the results of evolution?
1) isolation of organisms
2) the struggle for existence between organisms
3) heredity and variability in organisms
4) the formation of a new species

A sign of the amphibian class is
1) chitinous cover
2) bare skin
3) live birth
4) paired limbs

Among vertebrate animals, care for offspring is most strongly developed in
1) freshwater fish
2) amphibians
3) reptiles
4) mammals

Bright odorous flowers in angiosperms appeared in the process of evolution as an adaptation to
1) storage of nutrients
2) distribution of seeds and fruits
3) terrestrial habitation
4) attract insects

The lower plants are
1) mosses
2) algae
3) horsetails
4) ferns

What is the function of leaf stomata?
1) release water vapor into the atmosphere
2) absorb quanta of sunlight
3) prevent dust particles from entering the sheet
4) prevent harmful chemicals from entering the sheet

Infusoria slipper, unlike hydra,
1) uses oxygen for breathing
2) consists of one cell
3) has chloroplasts
4) feeds on ready-made organic substances

Insert in the text "Bacteria" the missing terms from the proposed list, using digital symbols for this. Write down the numbers of the selected answers in the text, and then enter the resulting sequence of numbers (in the text) into the table below.
BACTERIA
Among bacteria there is a group of organisms living in an oxygen-free environment, i.e. being __________ (A). Under unfavorable conditions, they can form __________ (B). Many bacteria have __________ (B) with which they move. Hereditary information in these microorganisms is stored in __________ (D).

LIST OF TERMS:
1) nucleus chromosome
2) aerobe
3) ring chromosome
4) anaerobe
5) pseudopod
6) dispute
7) flagellum
8) cyst

1) the emergence of seeds
2) the appearance of a flower
3) the occurrence of photosynthesis
4) the appearance of plant tissues
5) formation of root systems

What physiological process in unicellular animals is associated with the absorption of gases by the cell?
1) food
2) selection
3) reproduction
4) breathing

The cerebral cortex, which has furrows and convolutions, first appeared in
1) amphibians
2) reptiles
3) birds
4) mammals

The figure shows a representative of the department

1) Bryophytes
2) Ferns
3) Green algae
4) Angiosperms

Establish a correspondence between the plant and the method of its pollination: for each element of the first column, select the corresponding element from the second column.

PLANT
A) rosehip
B) cherry
B) sunflower
D) rye
D) alder

POLLINATION METHOD
1) insects
2) wind

Establish the sequence of subordination of systematic categories in plants, starting with the largest. Write down the corresponding sequence of numbers in your answer.

1) family of water lilies
2) Department of Angiosperms
3) view yellow capsule
4) genus Kubyshka
5) class Dicotyledonous
6) plant kingdom

How does sphagnum peat moss eat?
1) absorbs water and mineral salts by rhizoids
2) absorbs minerals from the soil by roots
3) forms organic substances from water and carbon dioxide
4) absorbs organic matter from water with the entire surface of its body

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My biology tutor's answers to these 200 questions of the FIPI OGE Open Task Bank of the section "System, Diversity and Evolution of Wildlife" and to all the other 1724 questions of this section you can

LAB #5

WATER EXCHANGE. LEAF AS A TRANSPIRATION ORGAN

Objective: study of the most important functional features of a plant leaf as an organ of transpiration: the structure and number of stomata on a leaf blade, the mechanism of opening and closing of stomata, the influence of various substances on the movement of stomata.

TRANSPIRATION

The biological significance of transpiration is, firstly, to ensure the constancy of the internal temperature of the leaf. This is achieved by the absorption of heat by water during its evaporation by leaves. The energy required to transfer a molecule from a liquid phase to a gaseous state without changing temperature is called heat of evaporation. The expenditure of heat for the evaporation of water is a means of regulating the temperature of the leaves and preventing the plants from overheating.

Secondly, transpiration, being the upper end engine, ensures the supply of water and mineral nutrients to the roots. The presence of a positive correlation between the intensity of transpiration and the flow of water and ions was established. If the leaves are removed from the plant, then the absorption of water by the roots stops. The suction action of transpiring leaves can be verified by placing a cut branch in a pipette filled with water and immersed in a cup of mercury. After some time, you can observe the rise of mercury in the pipette, which will indicate a significant suction force of the leaves.

Thus, the rate of water entry into the roots is determined by the intensity of transpiration.

Thirdly, transpiration prevents the occurrence of excessive turgor pressure, which could lead to the destruction of plant cells.

Fourthly, the process of transpiration is closely related to plant photosynthesis, which was noted by the works of K. A. Timiryazev. The assimilation of CO 2 by the leaves of plants occurs through the stomata, and it depends on the degree of saturation of the leaf tissue with water. The process of assimilation of water and carbon dioxide is a single and inseparable whole.

Under the intensity of transpiration is understood the amount of evaporated water per unit of time per unit of leaf area. Usually this indicator has a dimension - mg / dm 2 hour. The amount of water evaporated by plants is quite large, and often exceeds the amount of precipitation during the growing season. This excess is compensated by autumn-winter precipitation. So, for example, one sunflower or corn plant spends 200-250 liters of water over the summer. Wheat plants on an area of 1 ha evaporate about 2 million liters of water during the summer, corn - more than 3 million, and cabbage - up to 8 million liters. In the process of formation of one kilogram of plant mass, 300 liters are consumed. Water.

Stomatal transpiration is regulated by the degree of stomatal openness. Their structure and distribution depends on the species and ecological characteristics of plants. Stomata are found on all terrestrial parts of plants, including reproductive organs and even filaments. The most characteristic stomata for leaves. More often they are located on the underside of the leaves (in mesophytic plants). However, in xerophytes, they are also found on the upper side of the leaf.

The average number of stomata per 1 mm 2 of area ranges from 100 to 300. The size of the stomata does not exceed 20 microns in length and 8-15 microns in width. The total area of open stomata is 1% of the leaf surface.

It has been established that small apical leaves have a greater number of stomata than large lower ones. The frequency of stomata (their number per unit area) increases with the transition from the base of the leaf to its top and from the bottom of the plant to the top. Plants in arid habitats have more of them, but they are smaller in size.

In most mesophytic plants, the stomata are located at the same level as the epidermal cells, while in xerophytic forms, the stomata are located below the level of the epidermis and are called submerged. In hygrophytes, guard cells are sometimes located above the epidermis. Such stomata are called raised.

One or another type of stomata structure is characteristic of certain groups of plants, although within the same family, different types of stomata can sometimes be found. Despite the large area occupied by stomata, the diffusion of water vapor through them is 50-60% of evaporation from the free surface. It has been established that the rate of diffusion through small holes is proportional to their perimeter, and not to the area. Therefore, partial closing of the guard cells has little effect on their perimeter, and the level of water vapor diffusion through the stomata does not drop very sharply.

Experience 1. Observation of the movement of stomata under a microscope.

Purpose of experience: to determine the dependence of the work of stomata on osmotically active substances.

Materials and equipment: 5% glycerin solution, razor, dissecting needle, microscope, glass slides and coverslips.

Plants: leaves (Tradescantia, tulip, hydrangea or amaryllis, Kalanchoe).

Gas exchange between the intercellular spaces of the leaf and the external atmosphere is regulated by stomata. Each stomata consists of two guard cells, in which the walls adjoining the stomatal opening are strongly thickened, while the outer parts of the membrane remain thin. The unequal thickness of the outer and inner walls leads to the fact that when the turgor changes, the guard cells are able to bend or straighten, opening or closing the stomatal gap.

Progress: sections of the epidermis of the leaf of the selected plant are made, which are placed in a 5% solution of glycerol and incubated for at least 1 hour. The sections are examined under a microscope, the degree of opening of the stomatal fissure is determined using an eyepiece micrometer. Do 10 measurements, find the average value and calculate the error of the mean. Then the sections are transferred from the glycerol solution into water and the measurements of the stomatal fissures are repeated under a microscope. The results are entered in table 1.

Table 1

The degree of opening of the stomatal gap in different environments

plant, organ	No. of sounding	Degree of stomatal opening
plant, organ	No. of sounding	Glycerol
plant leaf

Exercise: to draw a conclusion about the effect of glycerol and water on the opening and closing of stomata.

Experience 2. Determination of the state of stomata and intercellular spaces by the Molisch method

Purpose of experience: will determine the influence of external conditions on the state of stomata and the intensity of transpiration.

Materials and equipment: xylene (in a dropper), ethyl alcohol (in a dropper); benzene (in a dropper), pipettes.

Plant: fresh or withered leaves of plants, leaves of plants that were in the dark.

The intercellular spaces of the leaf are usually filled with air, due to which, when viewed in the light, the leaf appears dull. If you infiltrate, i.e. filling the intercellular spaces with some liquid, then the corresponding parts of the leaf become transparent.

Determination of the state of stomata by the method of infiltration is based on the ability of liquids that wet the cell membranes to penetrate by capillarity through open stomatal slits into the nearest intercellular spaces, displacing air from them, which is easily seen by the appearance of transparent spots on the leaf. Different liquids are able to penetrate into stomatal openings that are open to varying degrees: xylene easily penetrates through slightly open stomata, benzene through medium open stomata, and ethyl alcohol can only penetrate through wide open stomata.

This method, proposed by Molisch, is very simple and quite applicable to work in the field.

Progress. Apply small drops of benzene, xylene and ethyl alcohol separately to the lower surface of the sheet. Hold the sheet in a horizontal position until the drops completely disappear, which can either evaporate or penetrate the inside of the sheet, and examine the sheet in the light.

Examine leaves aged in various conditions (fresh and withered, illuminated and shaded, etc.). Each time examine 2-3 sheets.

Determination of the state of stomata in indoor plants

The leaf of a plant performs various functions. This is the main organ in which photosynthesis, gas exchange and transpiration (evaporation of water) take place. For the implementation of gas exchange in the terrestrial organs of the plant, there are special formations - stomata.

Stomata, although they are part of the epidermis (leaf skin), are a special group of cells. The stomatal apparatus consists of two guard cells, between which there is a stomatal gap, 2–4 peristomatal cells, and a gas-air chamber located under the stomatal gap.

The guard cells of the stomata have an elongated-curved, "bean-shaped" shape. Their walls facing the stomatal fissure are thickened. Stomatal cells are able to change their shape - due to this, the opening or closing of the stomatal gap occurs. These cells contain chloroplasts (green plastids). The opening and closing of the stomatal fissure occurs due to changes in turgor (osmotic pressure) in guard cells. The chloroplasts of the guard cells contain starch, which can be converted into sugar. When starch is converted to sugar, the osmotic pressure increases and the stomata open. With a decrease in sugar content, the reverse process occurs, and the stomata close.

Stomatal slits are often wide open early in the morning and closed (or semi-closed) during the daytime. The number of stomata depends on environmental conditions (temperature, light, humidity). The degree of their disclosure at different times of the day varies greatly in different species. In the leaves of plants in humid habitats, the density of stomata is 100–700 per 1 mm2.

Most land plants have stomata only on the underside of the leaf. They can also be found on both sides of the leaf, as, for example, in cabbage or sunflower. At the same time, the density of stomata on the upper and lower sides of the leaf is not the same: cabbage has 140 and 240 per 1 mm 2, and sunflower has 175 and 325 per 1 mm 2, respectively. In aquatic plants, such as water lilies, stomata are located only on the upper side of the leaf with a density of about 500 per 1 mm 2. Underwater plants do not have stomata at all.

Objective:

determination of the state of stomata in various indoor plants.

Tasks

1. To study the question of the structure, location and number of stomata in various plants according to additional literature.

2. Select plants for research.

3. Determine the state of stomata, the degree of their opening in various indoor plants available in the biology room.

Materials and methods

The state of stomata was determined according to the method described in the Guidelines for Plant Physiology (compiled by E.F. Kim and E.N. Grishina). The essence of the technique is that the degree of opening of the stomata is determined by the penetration of certain chemicals into the pulp of the leaf. Various liquids are used for this purpose: ether, alcohol, gasoline, kerosene, benzene, xylene. We used alcohol, benzene and xylene provided to us in the chemistry lab. The penetration of these fluids into the flesh of the leaf depends on the degree of opening of the stomata. If a light spot appears on the leaf 2–3 minutes after applying a drop of liquid to the underside of the leaf blade, this means that the liquid penetrates through the stomata. In this case, alcohol penetrates into the leaf only with wide open stomata, benzene already with an average opening width, and only xylene penetrates through almost closed stomata.

At the first stage of the work, we tried to establish the possibility of determining the state of stomata (degree of opening) in various plants. Agave, cyperus, tradescantia, geranium, oxalis, syngonium, Amazonian lily, begonia, sanchetia, dieffenbachia, clerodendron, passionflower, pumpkin and beans were used in this experiment. Oxalis, geranium, begonia, sanchetia, clerodendron, passionflower, pumpkin and beans were selected for further work. In other cases, the degree of stomata opening could not be determined. This may be due to the fact that agave, cyperus, lily have rather hard leaves covered with a coating that prevents the penetration of substances through the stomatal gap. Another possible reason could be that by the time of the experiment (14.00 h) their stomata were already closed.

The study was carried out during the week. Every day after school, at 14.00, we determined the degree of stomata opening using the above method.

Results and discussion

The data obtained are presented in the table. The given data are averaged, because on different days, the state of the stomata was not the same. So, out of six measurements, a wide opening of stomata was recorded twice in oxalis, once in geranium, and an average degree of opening of stomata was recorded twice in begonia. These differences do not depend on the time of the experiment. Perhaps they are related to climatic conditions, although the temperature regime in the study and the illumination of plants were fairly constant. Thus, the obtained averaged data can be considered a certain norm for these plants.

The conducted research indicates that in different plants at the same time and under the same conditions, the degree of opening of stomata is not the same. There are plants with wide open stomata (begonia, sanchetia, pumpkin), the average size of the stomatal gap (sour, geranium, beans). Narrow stomatal slits are found only in Clerodendron.

We regard these results as preliminary. In the future, we plan to establish whether and how biological rhythms differ in the opening and closing of stomata in different plants. To do this, timing of the state of stomatal fissures during the day will be carried out.