Municipal stage of the All-Russian Olympiad for schoolchildren in biology. Inflorescence

The flower is a conspicuous, often beautiful, important part of flowering plants. Flowers can be large or small, brightly colored and green, odorless and odorless, single or collected together from many small flowers in one common inflorescence.

The flower is a modified shortened shoot that serves for seed reproduction... The main or lateral shoot usually ends in a flower. Like any shoot, a flower develops from a bud.

Flower structure

Flower - the reproductive organ of angiosperms, consisting of a shortened stem (flower axis), on which the flower cover (perianth), stamens and pistils, consisting of one or more carpels, are located.

The axis of the flower is called receptacle... The receptacle, expanding, accepts different shape flat, concave, convex, hemispherical, cone-shaped, elongated, columnar. The receptacle at the bottom turns into a peduncle connecting the flower with the stem or peduncle.

Flowers without pedicels are called sessile. On the peduncle, many plants have two or one small leaves - bracts.

Flower cover - perianth- can be dissected into a cup and a rim.

Cup forms the outer circle of the perianth, its leaves are usually relatively small size, Green colour... Distinguish between separate and systolic calyx. It usually serves to protect the inner parts of the flower before the bud opens. In some cases, the calyx drops when the flower opens, and most often it persists during flowering.

The parts of the flower located around the stamens and pistil are called the perianth.

The inner leaves are the petals that make up the corolla. The outer leaves - sepals - form a calyx. The perianth, consisting of a calyx and a corolla, is called double. The perianth, which is not subdivided into a corolla and a calyx, and all the leaves of the flower are more or less the same, is simple.

Corolla- the inner part of the perianth, differs from the calyx in its bright color and larger size. The color of the petals is due to the presence of chromoplasts. Distinguish between separate and joint-petal corollas. The first consists of individual petals. In spliced ​​corollas, a tube is distinguished and a bend perpendicularly located in relation to it, which has a certain number of teeth or blades of the corolla.

Flowers are symmetrical and asymmetrical. There are flowers that do not have a perianth, they are called naked.

Symmetrical (actinomorphic)- if many axes of symmetry can be drawn through the rim.

Asymmetrical (zygomorphic)- if only one axis of symmetry can be drawn.

Double flowers have an abnormally increased number of petals. In most cases, they result from the splitting of the petals.

Stamen- a part of a flower, which is a kind of specialized structure that forms microspores and pollen. It consists of a filament by means of which it is attached to the receptacle, and an anther containing pollen. The number of stamens in a flower is a systematic feature. Stamens are distinguished by the method of attachment to the receptacle, by the shape, size, structure of the filaments, the binder and the anther. The collection of stamens in a flower is called androecium.

Filament- the sterile part of the stamen, bearing the anther at its apex. The filament can be straight, curved, twisted, twisted, broken. In shape - hair-like, conical, cylindrical, flattened, clavate. By the nature of the surface - naked, pubescent, hairy, with glands. In some plants, it is short or does not develop at all.

Anther located at the top of the filament and attached to it by a binder. It consists of two halves, interconnected by a liaison. Each half of the anther has two cavities (pollen sacs, chambers, or nests) in which pollen develops.

As a rule, the anther is four-celled, but sometimes the partition between the nests in each half collapses, and the anther becomes two-celled. In some plants, the anther is even unicellular. Very rare in three-celled. By the type of attachment to the filament, there are stationary, mobile and swinging anthers.

The anthers contain pollen or pollen grains.

Pollen grain structure

The dust particles formed in the anthers of the stamens are small grains, and they are called pollen grains. The largest ones reach 0.5 mm in diameter, but they are usually much smaller. Under the microscope, you can see that the dust particles different plants are not at all the same. They differ in size and shape.

The surface of the dust grain is covered with various protrusions and tubercles. Once on the stigma of the pistil, the pollen grains are retained by outgrowths and sticky liquid released on the stigma.

The nests of the young anther contain special diploid cells. As a result of meiotic division, four haploid spores are formed from each cell, which are called microspores for their very small size. Here, in the cavity of the pollen sac, microspores turn into pollen grains.

It happens as follows: the microspore nucleus is mitotically divided into two nuclei - vegetative and generative. Around the nuclei, areas of the cytoplasm are concentrated and two cells are formed - vegetative and generative. On the surface of the cytoplasmic membrane of the microspore, a very strong shell is formed from the contents of the pollen sac, insoluble in acids and alkalis. Thus, each pollen grain consists of vegetative and generative cells and is covered with two membranes. A lot of pollen grains make up the pollen of the plant. The pollen matures in the anthers by the time the flower blooms.

Pollen germination

The beginning of pollen germination is associated with mitotic division, as a result of which a small reproductive cell is formed (sperm develops from it) and a large vegetative cell (a pollen tube develops from it).

After the pollen in one way or another gets on the stigma, its germination begins. Sticky and uneven surface stigma helps to retain pollen. In addition, the stigma secretes a special substance (enzyme) that acts on the pollen, stimulating its germination.

The pollen swells, and the restraining effect of the exine (the outer layer of the pollen grain shell) causes the contents of the pollen cell to rupture one of the pores through which the intina (the inner poreless shell of the pollen grain) protrudes outward in the form of a narrow pollen tube. The contents of the pollen cell pass into the pollen tube.

Under the epidermis of the stigma there is a loose tissue into which the pollen tube penetrates. It continues to grow, passing either through a special conductive channel between the mucous cells, or tortuously along the intercellular spaces of the conductive tissue of the column. In this case, a significant number of pollen tubes usually move simultaneously in the column, and the "success" of one or another tube depends on the individual growth rate.

Two sperm and one vegetative nucleus pass into the pollen tube. If the formation of sperm cells in the pollen has not yet occurred, then the generative cell passes into the pollen tube, and here, by its division, sperm cells are formed. The vegetative nucleus is often located in front, at the growing end of the tube, and sperm cells are sequentially located behind it. In the pollen tube, the cytoplasm is in constant motion.

Pollen is rich in nutrients. These substances, especially carbohydrates (sugar, starch, pentosans) are intensively consumed during pollen germination. In addition to carbohydrates in chemical composition pollen includes proteins, fats, ash and an extensive group of enzymes. The pollen contains a high content of phosphorus. Substances are in a mobile state in pollen. Pollen is easy to carry low temperatures up to - 20Cº and even lower, for a long time. High temperatures quickly reduce germination.

Pestle

The pistil is the part of the flower that forms the fruit. It arises from the carpel (leaf-like structure, bearing ovules) after the fusion of the edges of the latter. It can be simple, if it is composed by one carpel, and complex, if it is composed of several simple pistils, fused together by the side walls. In some plants, pistils are underdeveloped and are represented only by rudiments. The pistil is dismembered into an ovary, a column, and a stigma.

Ovary — Bottom part pistil, in which the seed buds are located.

Having entered the ovary, the pollen tube grows further and enters the ovule in most cases through the pollen duct (micropyle). Inserting itself into the embryonic sac, the end of the pollen tube bursts, and the contents are poured out onto one of the synergids, which darkens and rapidly disintegrates. The vegetative nucleus is usually destroyed before the pollen tube penetrates into the embryonic sac.

Flowers are right and wrong

Tepals (single and double) can be arranged so that several planes of symmetry can be drawn through it. Such flowers are called correct. Flowers through which one plane of symmetry can be drawn are called irregular.

Flowers bisexual and dioecious

Most plants have flowers that contain both stamens and pistils. This bisexual flowers... But in some plants, some flowers have only pistils - pistillate flowers, while others - only stamens - staminate flowers. Such flowers are called dioecious.

Plants are monoecious and dioecious

Plants on which both pistillate and staminate flowers develop are called monoecious. Dioecious plants have staminate flowers on one plant and pistillate flowers on another.

There are species in which bisexual and unisexual flowers can be found on one plant. These are the so-called polygamous (polygamous) plants.

Inflorescences

Flowers are formed on the shoots. Very rarely, they are located alone. More often flowers are collected in notable groups, which are called inflorescences. The beginning of the study of inflorescences was laid by Linnaeus. But for him, the inflorescence was not a type of branching, but a way of flowering.

In inflorescences, the main and lateral axes are distinguished (sessile or on pedicels), then such inflorescences are called simple. If the flowers are on the lateral axes, then these are complex inflorescences.

Inflorescence type	Inflorescence scheme	Peculiarities	Example
Simple inflorescences
Brush		Separate lateral flowers sit on an elongated main axis and at the same time have their own pedicels, approximately equal in length	Bird cherry, lily of the valley, cabbage
Ear		The main axis is more or less elongated, but the flowers are without legs, i.e. sedentary.	Plantain, orchis
Ear of ear		It differs from the spike in the fleshy, thickened axis.	Corn, calla
Basket		The flowers are always sessile and sit on the strongly thickened and widened end of the shortened axis, which has a concave, flat or convex appearance. In this case, the inflorescence outside has a so-called wrapper, consisting of one or many successive rows of bracts, free or accrete.	Chamomile, dandelion, aster, sunflower, cornflower
Head		The main axis is greatly shortened, the lateral flowers are sessile or almost sessile, closely spaced to each other.	Clover, scabiosa
Umbrella		The main axis is shortened; lateral flowers emerge, as it were, from one place, sit on legs of different lengths, located in the same plane or domed.	Primrose, onion, cherry
Shield		It differs from the brush in that the lower flowers have long pedicels, so that, as a result, the flowers are located almost in the same plane.	Pear, spirea
Complex inflorescences
Complex brush or broom		From the main axis there are lateral branching axes, on which flowers or simple inflorescences are located.	Lilac, oats
Sophisticated umbrella		Simple inflorescences extend from the shortened main axis.	Carrots, parsley
Complex ear		Individual spikelets are located on the main axis.	Rye, wheat, barley, wheatgrass

The biological significance of inflorescences

The biological significance of inflorescences is that small, often inconspicuous flowers, collected together, become noticeable, give the most large quantity pollen and better attract insects, which carry pollen from flower to flower.

Pollination

In order for fertilization to take place, it is necessary that the pollen gets on the stigma of the pistil.

The process of transferring pollen from the stamens to the stigma of the pistil is called pollination. There are two main types of pollination: self-pollination and cross-pollination.

Self-pollination

During self-pollination, pollen from the stamen enters the stigma of the pistil of the same flower. This is how wheat, rice, oats, barley, peas, beans, and cotton are pollinated. Self-pollination in plants most often occurs in an unopened flower, that is, in a bud, when the flower opens, it is already completed.

During self-pollination, germ cells that have formed on one plant and, therefore, have the same hereditary characteristics, merge. This is why the offspring resulting from the self-pollination process is very similar to the parent plant.

Cross pollination

With cross-pollination, a recombination of hereditary characteristics of the paternal and maternal organisms occurs, and the resulting offspring can acquire new properties that the parents did not have. Such offspring are more viable. In nature, cross-pollination is much more common than self-pollination.

Cross-pollination is carried out using various external factors.

Anemophilia(wind pollination). In anemophilous plants, flowers are small, often collected in inflorescences, a lot of pollen is formed, it is dry, small, when the anther is opened, it is thrown out with force. Light pollen from these plants can be carried by the wind over distances of up to several hundred kilometers.

Anthers are located on long thin filaments. The stigma of the pistil is wide or long, feathery and protruding from the flowers. Anemophilia is characteristic of almost all cereals and sedges.

Entomophily(transport of pollen by insects). The adaptation of plants to entomophilia is the smell, color and size of flowers, sticky pollen with outgrowths. Most flowers are bisexual, but the maturation of pollen and pistils does not occur simultaneously, or the stigma height is greater or less than the height of the anthers, which serves as protection against self-pollination.

In the flowers of insect pollinated plants, there are areas that emit a sweet aromatic solution. These areas are called nectaries. Nectars can be found in different places of the flower and have different shapes... Insects, flying up to the flower, reach for nectaries and anthers and get dirty with pollen during the meal. When the insect moves to another flower, the pollen grains carried by it adhere to the stigmas.

When pollinated by insects, less pollen is wasted and therefore the plant conserves substances by producing less pollen. The pollen grains do not need to stay in the air for long and can therefore be heavy.

Insects can pollinate sparsely located flowers and flowers in calm places - in forest thickets or thicker grass.

Typically, each plant species is pollinated by several species of insect, and each species of pollinator serves several species of plants. But there are plant species whose flowers are pollinated by insects of only one species. In such cases, the mutual correspondence of the ways of life and the structure of flowers and insects is so complete that it seems miraculous.

Ornithophilia(pollination by birds). Typical for some tropical plants with brightly colored flowers, abundant secretion of nectar, strong elastic structure.

Hydrophilia(pollination with water). Observed in aquatic plants... The pollen and stigma of these plants are most often filamentous.

Bestiality(pollination by animals). These plants are characterized by large flower sizes, abundant secretion of nectar containing mucus, mass production of pollen, when pollinated. bats- bloom at night.

Fertilization

The pollen grain gets on the stigma of the pistil and attaches to it due to the peculiarities of the structure of the shell, as well as the sticky sugary secretions of the stigma, to which the pollen adheres. The pollen grain swells and grows into a long, very thin pollen tube. The pollen tube is formed as a result of division of the vegetative cell. First, this tube grows between the cells of the stigma, then - of the column, and finally grows into the cavity of the ovary.

The generative cell of the pollen grain moves into the pollen tube, divides and forms two male gametes (sperm). When the pollen tube enters the embryo sac through the pollen duct, one of the sperm is fused with the egg. Fertilization occurs and a zygote is formed.

The second sperm is fused with the nucleus of the large central cell of the embryonic sac. Thus, in flowering plants, two fusions occur during fertilization: the first of the sperm fuses with the egg, the second with a large central cell. This process was discovered in 1898 by a Russian botanist, academician S.G. Navashin and named it double fertilization... Double fertilization is typical only for flowering plants.

The zygote formed during the fusion of gametes is divided into two cells. Each of the cells that arose in this process divides again, and so on. As a result of multiple cell divisions, a multicellular embryo of a new plant develops.

The central cell also divides to form endosperm cells, which store nutrient stores. They are necessary for the nutrition and development of the embryo. The seed coat develops from the ovule cover. After fertilization, a seed develops from the ovule, consisting of a peel, an embryo and a supply of nutrients.

After fertilization, the ovary receives nutrients and it gradually turns into a ripe fruit. The pericarp, which protects the seeds from adverse effects, develops from the walls of the ovary. In some plants, other parts of the flower are also involved in the formation of the fruit.

Dispute formation

Simultaneously with the formation of pollen in the stamens, a large diploid cell is formed in the ovule. This cell divides meiotically and gives rise to four haploid spores, which are called macrospores, since they are larger in size than microspores.

Of the four formed macrospores, three die off, and the fourth begins to grow and gradually turns into an embryonic sac.

Embryo sac formation

As a result of three-fold mitotic division of the nucleus in the cavity of the embryonic sac, eight nuclei are formed, which are clothed with cytoplasm. Cells devoid of shells are formed, which are arranged in a certain order. At one pole of the embryonic sac, an egg apparatus is formed, consisting of an egg and two auxiliary cells. At the opposite pole there are three cells (antipodes). One nucleus (polar nuclei) migrates from each pole to the center of the embryo sac. Sometimes the polar nuclei merge and form the diploid central nucleus of the embryo sac. The embryonic sac, in which the nuclei have differentiated, is considered mature, it can perceive sperm.

By the time the pollen and the embryo sac ripen, the flower opens up.

The structure of the ovule

The ovules develop on inner sides the walls of the ovary and, like all parts of the plant, are composed of cells. The number of ovules in the ovaries of different plants is different. In wheat, barley, rye, cherry, the ovary contains only one ovule, in cotton - several dozen, and in poppy, their number reaches several thousand.

Each ovule is covered with a cover. At the top of the ovule there is a narrow channel - the pollen passage. It leads to the tissue that occupies the central part of the ovule. In this tissue, as a result of cell division, an embryonic sac is formed. Opposite the pollen passage, there is an ovum in it, and the central part is occupied by a large central cell.

The development of angiosperms (flowering) plants

Seed and fruit formation

During the formation of a seed and a fetus, one of the sperm fuses with the egg, forming a diploid zygote. Subsequently, the zygote divides many times, and as a result, a multicellular plant embryo develops. The central cell, fused with the second sperm, also divides many times, but the second embryo does not arise. A special tissue is formed - endosperm. The endosperm cells accumulate reserves of nutrients necessary for the development of the embryo. The ovule covers grow and turn into a seed coat.

Thus, as a result of double fertilization, a seed is formed, which consists of an embryo, storage tissue (endosperm) and seed coat. From the wall of the ovary, the wall of the fetus is formed, called the pericarp.

Sexual reproduction

Sexual reproduction of angiosperms is associated with the flower. Its most important parts are stamens and pistils. Complex processes associated with sexual reproduction take place in them.

In flowering plants, the male gametes (sperm cells) are very small, while the female gametes (eggs) are much larger.

In the anthers of the stamen, cell division occurs, as a result of which pollen grains are formed. Each pollen grain of angiosperms consists of vegetative and generative cells. The pollen grain is covered with two shells. The outer shell, as a rule, is uneven, with spines, warts, and outgrowths in the form of a mesh. This helps the pollen grains stay on the stigma of the pistil. The pollen of the plant, which matures in the anthers, by the time the flower blooms, consists of many pollen grains.

Flower formula

For the conditional expression of the structure of flowers, formulas are used. To draw up a flower formula, the following designations are used:

An example of a cherry blossom formula:

* H 5 L 5 T ∞ P 1

Flower diagram

The structure of a flower can be expressed not only by a formula, but also by a diagram - a schematic representation of a flower on a plane perpendicular to the axis of the flower.

A cross-sectional diagram of unopened flower buds is plotted. The diagram gives a more complete idea of ​​the structure of a flower than a formula, since it also shows the relative position of its parts, which cannot be shown in the formula.

Municipalstage of the All-Russian Olympiad for schoolchildren in biology

Khanty-Mansiysk autonomous region- Ugra

2015-2016 academic year

Grade 9

Congratulations on your participation in municipal stage All-Russian Olympiad for schoolchildren in biology! When answering questions and completing tasks, do not rush, since the answers are not always obvious and require the use of not only biological knowledge, but also general erudition, logic and creativity.Time for completing tasks is 180 minutes (3 hours). The maximum score is 68. Success in your work!

Part I.

You are offered test tasks, requiring the choice of only one answer out of four possible. The maximum number of points that can be collected is 30 (1 point for each test task). Indicate the index of the answer that you consider the most complete and correct in the matrix of answers.

1. Mycobacteria are pathogens:

a) syphilis;

b) jaundice;

c) tuberculosis;

d) mycoses.

2. Kukushkin flax reproduces:

a) zoospores;

b) seeds under unfavorable conditions;

c) disputes;

d) aplanospores.

3. Red algae differ from green and brown algae in that:

a) red algae do not form chlorophyll a;

b) red algae do not have a sexual process;

c) unicellular red algae were not found;

d) in life cycle red algae lack cells with flagella.

4. Of the listed algae are capable of absorbing organic matter from the environment:

a) spirogyra and fucus;

b) spirogyra and ulotrix;

c) chlamydomonas and chlorella;

d) kelp and fucus.

5. In the basket of the plant depicted

in the picture, flowers:

a) reed;

b) false lingual;

c) tubular and pseudo-lingual;

d) reed and tubular

6. Strawberry leaves:

a) odd-pinnate;

b) ternary;

c) finger-complex;

d) complex one-leaf.

7. On a cross-section of the stem of a 3-year-old linden, you can see:

a) cambium, the core is inward from it, and the bark is outward;

b) cambium, wood is inside of it, and bark is outside;

c) procambium, bark outside of it, and wood inside;

d) procambium, outward from it a central cylinder, and inward - wood.

8. In one cell of the pulp of a mature rowan fruit under a microscope, you can see plastids:

a) leukoplasts, chloroplasts and chromoplasts;

b) leukoplasts and chloroplasts;

c) leukoplasts and chromoplasts;

d) chromoplasts.

9. Underground seed germination is typical for:

a) castor bean;

c) pumpkins;

d) pedunculate oak.

10. Resin passages are typical for:

a) conifers;

b) Compositae;

c) umbrella;

d) all the listed plants.

11. What blood is in the heart of the edentulous: venous (low oxygen) or arterial (oxygenated)?

a) venous;

b) arterial;

c) venous in the atria, and arterial in the ventricle;

d) arterial in the left atrium, venous in the right atrium, mixed in the ventricle.

12. What is the filling of the pericardial sinus in crayfish?

a) water;

b) coelomic fluid;

c) arterial blood;

d) venous blood.
13. How are representatives of this species of animals (see figure) dangerous to humans?

a) carriers of protozoa - pathogens dangerous disease;

b) carriers of bacteria - causative agents of a dangerous disease;

c) have poisonous glands, the bite is dangerous for people with diseases of the cardiovascular system;

d) are not dangerous in any way.

14. The figure shows an organ of movement characteristic of:

a) jellyfish;

b) crustaceans;

c) echinoderms;

d) annelids.

15. How does crayfish breathe?

a) atmospheric oxygen;

b) oxygen dissolved in water;

c) in different ways, depending on the degree of pollution of the reservoir;

d) differently, depending on the season.

16. To which group of insects are termites closest?

a) bees;

b) ants;

c) cockroaches;

d) Orthoptera.
17. Which of these groups of animals has a class rank in the classification?

a) bats;

b) brachiopods;

c) gastropods;

d) pterygopods.

18. The mask is part oral apparatus:

a) soldier termites;

b) gravedigger beetles;

c) spider-cross;

d) dragonfly larvae.

a) echinococcus;

b) roundworm;

c) cat fluke;

d) bovine tapeworm.

a) echinococcus;

b) malaria plasmodium;

c) dysentery amoeba;

d) whipworm.

21. Which bird specializes in collecting food in flight?

a) blackbird;

b) robin;

c) finch;

d) black swift.

22. Which of the mammals is characterized by the absence of canines in the dental system?

a) manul;

b) shrew;

c) zebra;

d) gopher.

23. Which bird makes nests in the hollows?

a) field thrush;

b) common nuthatch;

c) black-headed warbler;

d) green warbler.

24. What class are the worms?

a) cyclostomes;

b) mammals;

c) reptiles;

d) amphibians.
25. How polar bear hunts penguins in nature?

a) knocks down with a paw in the air;

b) waiting in ambush;

c) catching up by swimming;

d) nothing.

26. In passerines, a short, powerful beak is associated with feeding:

a) seeds;

b) fruits;

c) large animal food;

d) insects.

27. When a dog marks someone else's urinary tag, this is an example:

a) motivation;

b) signaling;

c) orientation;

d) communication.

28. In birds, the leading sense organ is:

a) vision;

b) sense of smell;

d) touch.

29. Which of the listed types better satisfies the concept

"R-strategist"?

A) grass frog;

b) African elephant;

c) bank vole;

d) viviparous lizard.

30. Which of the mammals is characterized by the absence of canines in the dental system?

a) red nocturnal;

b) white hare;

31. The bones of the roof of the skull belong to the bones:

a) airborne;

b) spongy;

c) flat;

d) tubular.

32. Unlike an adult, a child under 6-7 years old does not have:

a) incisors;

b) canines;

c) small molars;

d) large molars.
33. Resting membrane potential with increasing concentration of extracellular potassium:

a) increases;

b) does not change;

c) decreases;

d) changes sign.

34. In skeletal muscles, the appearance of calcium in the cytoplasm is due to:

a) activation of calcium pumps;

b) activation of the sodium-calcium exchanger;

c) closing potential-sensitive channels in the membrane of the endoplasmic reticulum;

d) the opening of calcium-dependent calcium channels in the membrane of the endoplasmic reticulum.

35. Striated fibers are characteristic of muscle tissues, which provide:

a) turns of the eyeball;

b) compression of the walls of the lymphatic vessels;

c) constriction of the pupil;

d) pupil dilation.

36. The salivation centers are located in:

a) midbrain;

b) the cerebellum;

c) diencephalon;

d) the medulla oblongata.

37. The lining cells of the gastric mucosa secrete:

a) pepsinogen;

b) trypsinogen;

c) hydrochloric acid;

d) alpha-amylase.

38. Erythrocytes placed in a hypertonic solution:

a) burst, releasing the contents in environment;

b) decrease in volume and shrink;

c) retain their disc-like shape due to the activation of electrolyte transfer systems;

d) stick together (agglutinate) with the formation of a precipitate.

39. Organoids found in cells of both prokaryotes and eukaryotes:

a) endoplasmic reticulum;

b) mitochondria;

c) lysosomes;

d) ribosomes.

40. Animals that live in soil and caves have some things in common. Find one wrong one among them.

a) reduction of pigmentation;

b) reduction of visual perception;

c) reduction of all sense organs;

d) adaptation to constant abiotic conditions.

Part II.

You are offered test items with one answer out of four possible, but requiring multiple prior choice. The maximum number of points that can be collected is 20 (2 points for each test task). Indicate the index of the answer that you consider the most complete and correct in the matrix of answers.

1. 
   Ciliates balantidia - 1) lives in fresh water bodies, 2) moves with the help of flagella, 3) does not have a contractile vacuole, 4) carries out the sexual process - conjugation, 5) has one nucleus.

1. 
   The animal depicted in the figure - 1) is covered with horny scales, 2) reproduces at the larval stage (neotenic), 3) has one lumbar vertebra, 4) performs double breathing, 5) does not have a hard palate.

1. 
   The optical system of the eye includes - 1) the pupil, 2) the cornea, 3) the sclera, 4) the lens, 5) the retina.

1. 
   Of these substances, water-soluble - 1) beta-carotene, 2) erythrosis, 3) ATP-ase, 4) maltose, 5) inulin.

Part III.

You are offered test tasks in the form of judgments, with each of which you must either agree or reject. In the matrix of answers, indicate the answer option "yes" or "no" by placing an X in the appropriate column. The maximum number of points that can be collected is 10 (1 point for each task).
1. All autotrophic organisms are also phototrophic.

2. Of the total light energy reaching photosynthetic organisms, about 1% of the visible light is used by them.

3. The intensity and quality of light changes vertically in the forest canopy.

4. The body of lower plants is always represented by a thallus with large leaves.

5. Hawthorn thorns are modified shoots.

6. The germ of the seed on the most early stages germination is heterotrophic.

7. Doubling fish is an extinct group of fish from which the first amphibians originated.

8. Mixins do not have a larval stage in the development cycle.

9. All representatives of the type Chordate dioecious animals. 10. Regeneration in polyps occurs due to the division of skin-muscle cells.

11. All invertebrates use external fertilization.

12. The bulk of the muscles in birds is located on the ventral side.

13. The group of mammalian skin glands includes sweat, sebaceous and milk glands.

14. The main organ that, under the influence of the hormone insulin, provides a decrease in blood glucose levels, is the liver.

15. Strict bed rest for a month does not affect the water and electrolyte balance of the blood.
Part IV.

You are offered test tasks that require matching. The maximum number of points that can be scored is 8. Fill in the answer matrices in accordance with the requirements of the tasks.

1. Compare the named biochemical processes and organelles in which these processes take place.

2. In mammals, hormones are involved in the regulation of numerous processes. Relate using letter designations, the names of these hormones are indicated by numbers, with their functions indicated by letters.

3. Establish a correspondence between the forms of cells of pathogens of bacterial infections (1 - 4) and the diseases that they cause (A - H).

41. In the picture, sign the names of the parts of the flower

1 - stigma of the pistil

2 - column

3 - ovary

4 - ovules

5 - receptacle

6 - pedicel

7 - sepal

8 - stamen

9 - petal

10 - perianth

42. Compare the cherry and tulip flowers shown in the picture. Sign the main parts of them. What are the similarities in the structure of these flowers? What is the difference?

1 - petal

2 - stamen

3 - pistil

4 - pedicel

Similarity: flowers are bisexual, regular, with a perianth and pedicel, a corolla of a loose-leafed

Difference: the cherry has many stamens, the tulip has a multiple of 3. The cherry has a double perianth, the tulip has a simple one. Cherry has a lower ovary, a tulip has an upper

43. Execute laboratory work"The structure of a flower". Draw parts of the flower and sign their names

44. Think, on the basis of which it can be argued that the flower is a modified shoot. Give a reasoned answer

The flower is a modified shoot, as it develops from a bud. The stem part of it is represented by a pedicel and a receptacle, and the calyx, corolla, stamens and pistils are modified leaves

45. Compare the flowers of cabbage and viola shown in the picture. What is the difference between them?: Sign, as such flowers are called

Correct - cabbage, wrong - viola. Several planes of symmetry can be drawn through the correct flower, one through the wrong one.

46. ​​Fill in the missing words

Bisexual

Stamen, pistil, pistillate

Monoecious

It's no secret that many plants are covered with flowers, which are modified shoots. Moreover, some plants have single flowers, and some have whole inflorescences. What is an inflorescence? So, an inflorescence is not just a modified shoot, but a whole system of shoots, from which fruits with seeds subsequently appear.

Inflorescence classification

In botany, there are many different ways classification of types of inflorescences: depending on the presence of leaves on them, depending on their branching, in the direction of leaf opening, and so on. But the most popular method is the classification of inflorescences according to the degree of their branching, according to it, all inflorescences, first of all, can be divided into simple and complex.

Simple inflorescences

• umbrella,
• brush,
• ear,
• shield,
• head,
• basket.

You can dwell on some of them in more detail.

In the picture, the inflorescence is an umbrella, on it all the pedicels go from the top of the inflorescence axis. An example of an umbrella inflorescence would be a cherry.

Here we have a cluster inflorescence, it has separate flowers, located one after another on well-visible pedicels. Examples of brush inflorescences can be lily of the valley (shown in the picture), bird cherry, cabbage.

Inflorescence of spikes - forms flowers that do not have pedicels, they are located on the common axis of the inflorescence, such as in plantain.

The inflorescence of the basket is distinguished by the fact that it usually contains numerous small sessile flowers located on a thick and wide bed of the inflorescence. Examples of inflorescences of a basket can be inflorescences of sunflower, dandelion, aster, sow thist and many other plants.

Complex inflorescences

Complex inflorescences, in turn, are formed from simple ones, as a result of the branching of the main axis. Examples of complex inflorescences can be panicle, compound spike, compound umbrella, etc.

The inflorescence of a complex spike in the picture is distinguished by the fact that several spikelets sit on it in a common axis, each of which is formed by several flowers. An example of a complex spike inflorescence is rye.

What does the inflorescence do

What is practical use and the significance of inflorescences in biology? It is very important, because inflorescences play a big role in pollination of flowers, it is thanks to them that the efficiency of this very pollination increases. It is much easier and easier for insects to notice very large inflorescence than small flowers... Also, thanks to the inflorescences, it is more convenient for them to fly from one flower to another.

Inflorescences, video

And in conclusion, a thematic video with a detailed story about inflorescences.

Task 1. "Reproduction of flowering plants"

Task 3. “Flowering. General characteristics" Give your answer in one sentence: 1. How many species does the Angiosperms department include? 2. Life forms of flowering plants? 3. How is the flowering sporophyte represented? 4. How is the male gametophyte of flowering plants represented? 5. How is the female gametophyte of flowering plants represented? 6. The main aromorphoses that led to the appearance of flowering? 7. How are flowering microsporangia represented? 8. What are the flowering megasporangia represented by? 9. What are flowering gametangia? 10. When does meiosis occur in the life cycle of flowering plants - during the formation of gametes or spores? 11. What develops from flowering microspores and megaspores? 12. To which group do flowering plants belong - equal to - or heterogeneous plants? Task 4. "Evolution of plants" Review the drawing and answer the questions:

1. First flowering plants appeared (_).

2. Flowering descended from (_).

3. Evantian, strobilar hypothesis of the origin of the flower assumes that the flower (_).

4. According to the pseudantium hypothesis, the flower is (_).

** Task 6. "Origin of the flower"

Review the drawing and answer the questions:

1. Write down the numbers under which the signs characteristic of monocotyledonous plants are drawn.

2. Write down the numbers under which the traits characteristic of dicotyledonous plants are drawn.

3. Which plants, dicotyledonous or monocotyledonous, are more ancient?

Task 8. "Dicotyledonous plants"

The number of cotyledons in a seed embryo is (_). The spare nutrients in the seed can be found in (_), in (_), or (_).

The petiole of the leaf is more common (_). Cambium in a stem (_). Conductive bundles in the (_) type are located in the stem (_). Root system usually (_). Secondary thickening of the stem and root (_). Life forms are (_) and (_) plants. The number of flower parts is usually a multiple of (_) or (_). The perianth is more often (_).

Task 9. "Monocotyledonous plants"

Write down question numbers and missing words (or groups of words):

1. The number of cotyledons in the embryo of the seed - (_).

2. The spare nutrients in the seed are in (_).

3. Leaf vein usually (_).

4. Petiole at the leaf more often (_).

5. Cambium in the stem (_).

6. Conducting bundles in the (_) type, located in the stem (_).

7. The root system is usually (_).

8. Secondary thickening of the stem and root (_).

9. Life forms - (_) plants.

10. The number of parts of flowers is usually a multiple (_).

11. Perianth more often (_).

Task 10. "Cruciferous family"

Review the drawing and answer the questions:

How many species does the Rosaceae family unite? What life forms are the plants of the family represented? What is the formula of the Rosaceae flower? Try to guess: who are the five brothers, two are beards, two are beardless, and the last fifth seems to be a freak - only the beard on the right, there is not a trace on the left. What are the fruits of the plants shown in the picture? What are the leaves of Rosaceae? What groups of plants are distinguished in the family?

Task 12. "Legumes family"

Review the drawing and answer the questions:

How many species does the legume family share? What life forms are the plants of the family represented? What is indicated in the figure by the numbers 1 - 8? What is the formula of a legume flower? What inflorescences are typical for legumes? What are the fruits of legumes? What are the leaves of the legumes shown in the picture? What is the significance of the plant family? Why are legumes called "Veal Veal"? Why are legumes called "live fertilizers"?

Task 13. "Family of Solanaceae"

Review the drawing and answer the questions:

How many species does the Solanaceae family unite? What life forms are the plants of the family represented? What is the formula of the nightshade flower? What are the fruits of nightshades? What are the leaves of nightshades? What is the significance of the plant family? What poisonous plants of the family do you know?

Task 14. "Compositae family"

Review the drawing and answer the questions:

How many species does the Asteraceae family unite? What life forms are the plants of the family represented? What flowers are marked with numbers 1 - 4? What inflorescence do all the plants in the family have? What fruits (5) do Compositae have? What is the significance of the plant family?

Task 15. “Class Monocotyledonous. Liliaceae family "

Review the drawing and answer the questions:

How many species does the Liliaceae family unite? What life forms are the plants of the family represented? What is the formula of the lily flower? What are the fruits of liliaceae? What underground shoots are typical for liliaceae? What is the significance of the plant family?

Task 16. “Class Monocotyledonous. Cereals family "

Review the drawing and answer the questions:

1. What is the number on the cruciferous chart? Flower formula? Fruit?

2. What is the number for the Rosaceae chart? Flower formula? Fruit?

3. What is the number on the legume diagram? Flower formula? Fruit?

4. What is the number on the nightshade diagram? Flower formula? Fruit?

5. What is the number in the Compositae diagram? Types of flowers? Inflorescences? Fruit?

6. What are the numbers for the diagrams of monocots? Flower formulas? Fruit?

Answers:

Exercise 1. 1.1 - ovules; 2 - embryonic sac; 3 - stamen; 4 - pollination; 5 - germination of the pollen tube; 6 - double fertilization; 7 - seed; 8 - seedling, developing sporophyte. 2. Seeds are formed inside the pericarp.

Task 2.

	Flowering
1. Number of species 3. Male gametophyte 4. Female gametophyte 5. Fertilization 7. Ovules 8. Location of ovules 10. Tracheids in the xylem 11. Tracheas in the xylem 12. Sieve cells in the bast 13. Sieve tubes in the bast 14. Life forms	About 700 species Absent Pollen grain Endosperm with two archegonia Sperm + egg Absent Formed Two on the scale of a female cone Formed Absent Only arboreal, trees and shrubs	Formed Pollen grain Embryo sac Formed Formed Inside the ovary of the pistil Formed Trees, shrubs, herbs

Task 3. 1. About 250 thousand species. 2. Trees, shrubs, shrubs, semi-shrubs, vines, herbaceous plants. 3. A leafy plant. 4. Pollen grain. 5. The embryonic sac. 6. The appearance of a flower and a fruit. 7. Pollen nests of the anther. 8. Nucellus in the ovule. 9. None. 10. When a dispute is formed. 11. Gametophytes. 12. Diverse plants.

Task 4. 1. Sporophytes in algae are often absent, diploid zygote; in mosses - a box on a leg; in lymphatics, horsetails, ferns, gymnosperms and flowering plants, it is a leafy plant. 2. Gametophytes in algae are more often represented by the thallus, which forms gametes; in mosses - a leafy plant; in lymphatics, horsetails and ferns - an outgrowth, in gymnosperms with a pollen grain and an endosperm with two archegonia; in angiosperms - pollen grain and embryo sac. 3. Sporophyte develops and gametophyte is reduced.

Task 5. 1. In the Mesozoic era in the Cretaceous. 2. From non-specialized ancient gymnosperms. 3. This is a modified shortened spore-bearing shoot, originally resembling a gymnosperm cone. Megasporophylls turned into carpels, microsporophylls - into stamens. 4. A collection of reduced heterosexual strobilus fused together.

Task 6. 1.1 - apocarpous; 2 - syncarpous; 3 - lysicarpous (carpels grow together laterally, but their walls then collapse, preserving the central column, to which the ovules are attached); 4 - paracarpous (occurs as a result of fusion of carpels along the edges). 2. Monocarp. 3. Syncarpous, lysicarp, paracarpous. 4. Cenocarpous gynoecium, in which the boundaries of fusion are invisible, and the only nest of the ovary bears only one ovule.

Task 7. 1. Signs of monocots: 2, 3, 4, 5, Signs of dicots: 1, 6, 7, 8, Dicots are more ancient.

Task 8. 1. Two. 2. Endosperm, perisperm or cotyledons. 3. Mesh. 4. Present. 5. Available. 6. Open; round. 7. Core. 8. Happens. 9. Herbaceous and woody plants... 10. Four or five. 11. Double.

Task 9. 1. One. 2. Endosperm. 3. Arc or parallel. 4. None. 5. None. 6. Closed; in two or more rings. 7. Fibrous. 8. None. 9. Usually herbaceous plants. 10. Three. 11. Simple.

Task 10. 1. About 3200 species. 2. Herbaceous plants prevail. 3. * Ch4L4T2 + 4P1. 4. Pods or pods. 5. Simple and complex. 6. Vegetable and ornamental plants.

Task 11. 1. About 3000 species. 2. Herbaceous plants, shrubs and trees. 3. * Ч5Л5Т∞П1, * Ч5Л5Т∞П∞., Or * Ч5 + 5Л5Т∞П∞ 4. Sepals near the dog rose (see figure). 5. Rosehip - false fruits from a concave overgrown receptacle (cinarodia) and inside the real fruits - nuts; cherry - drupe; strawberries - false fruits from a convex overgrown receptacle (fraga, or strawberry) and real nuts (polynuts); blackberry - prefabricated drupe (drupe); apple and pear - apple. 6. Simple and complex. 7. Fruit and berry, decorative.

Task 12. 1. More than 12,000 species. 2. Trees, shrubs, grasses. 3. 1 - sepals; 2 - sail; 3 - oars; 4 - boat; 5 - pestle; 6 - ten stamens; 7 - bean fruit; 8 - nodules on the roots of peas. H (5) L1 + 2 + (2) T (9) + 1P1 or H (5) L1 + 2 + (2) T (10) P1. 5. Brush, head. 6. Beans. 7. In peas - pinnate; beans have trifoliate; in peanuts and yellow acacia, pinnate; in lupine they are finger-complex. 8. There are food plants (peas, beans, soybeans), there are decorative (caragana, or yellow acacia, robinia, or white acacia, sweet peas), fodder (clover, alfalfa), medicinal plants (sweet clover). 9. They contain a lot of protein. 10. Together with the roots, nitrogen compounds formed by nodule bacteria remain in the soil.

Task 13. 1. About 3000 species. 2. Grasses, shrubs, in tropical latitudes - even trees. 3. * H (5) L (5) T5P1. 4. Berry or box. 5. Simple and complex. 6. Food plants (potatoes, tomatoes, eggplants, annual peppers), decorative (petunia, fragrant tobacco). 7. Helen, dope, belladonna, tobacco.

Task 14. 1. About 25,000 species. 2. Herbaceous plants, shrubs are found in tropical countries. 3. 1 - tubular, 2 - reed, 3 - pseudo-reed, 4 - funnel-shaped. 4. Basket. 5. Achenes. 6. Food (sunflower, salad); decorative (asters, dahlias, chrysanthemums); many medicinal plants (medicinal dandelion, medicinal chamomile).

Task 15. 1. About 4000 species. 2. Perennial herbaceous plants. 3. * O3 + 3T3 + 3P1. 4. Berry or box. 5. Rhizomes and bulbs. 6. Vegetable (asparagus, onion, garlic); decorative (lilies, tulips, hyacinths, aloe), medicinal (raven's eye, May lily of the valley).

Task 16. 1.1 - spikelet scales; 2 - flower scales; 3 - pistil with two bifurcated fluffy stigmas; 4 - stamens; 5 - two flowering films; 6 - a stem of a straw; 7 - sheath of the leaf; 8 - the fruit of the weevil. 2. Most are herbaceous plants, but there are shrubs and woody forms. 3. Flowers have two flower scales, two flower films, three stamens and one pistil, flower formula - O (2) + 2Т3П1. 4. Composite ear, panicle, ear, sultan. 5. Caryopsis. 6. Vaginal, narrow, long, with parallel venation. 7. Most cereals have a straw stem. 8. Cereals (wheat, rye, corn, rice and others) are the main food product containing protein.

Task 17. 12; * Ch4L4T2 + 4P1. Fruit pods or pods. 2. 6; * Ch5L5T∞P1, * Ch5L5T∞P∞., Or * Ch5 + 5L5T∞P∞. False fruits of the rose hips are from a concave overgrown receptacle (cinarodia) and inside the real fruits are nuts; false fruits from a convex overgrown receptacle (fraga, or strawberry) and real fruits of nuts (polynuts); drupe; prefabricated drupe (drupe); Apple. 3. 7; H (5) L1 + 2 + (2) T (9) + 1P1 or H (5) L1 + 2 + (2) T (10) P1. The fruits are beans. 4.1; * H (5) L (5) T5P1. The fruits are a berry or a box. 5.4; Flowers - tubular, ligulate, pseudo-ligate, funnel-shaped. The inflorescence is a basket. The fruits are achenes. 6. 3 - liliaceae; * O3 + 3T3 + 3P1. The fruits are a berry or a box. 5 - cereals; O (2) + 2Т3П1. The fruits are caryopses.