This handbook contains all the theoretical material on the biology course required to pass the exam. It includes all elements of the content, checked by control and measuring materials, and helps to generalize and systematize knowledge and skills for the course of the secondary (complete) school.
The theoretical material is presented in a concise, accessible form. Each section is accompanied by examples of test tasks that allow you to test your knowledge and the degree of preparedness for the certification exam. Practical tasks correspond to the USE format. At the end of the manual, answers to tests are given that will help schoolchildren and applicants to test themselves and fill in the gaps.
The manual is addressed to schoolchildren, applicants and teachers.
Reproduction of ciliates occurs both asexually and sexually. During asexual reproduction, longitudinal cell division occurs. During the sexual process, a cytoplasmic bridge is formed between two ciliates. Polyploid (large) nuclei are destroyed, and diploid (small) nuclei are divided by meiosis with the formation of four haploid nuclei, three of which die, and the fourth is divided in half, but already by mitosis. Two nuclei are formed. One is stationary and the other is migratory. Then between the ciliates there is an exchange of migrating nuclei. Then the stationary and migrating nuclei merge, the individuals disperse, and large and small nuclei are again formed in them.
A1. The taxon that unites all the protozoa is called
1) kingdom
2) sub-kingdom
A2. The simplest do not
2) organelles 4) sexual reproduction
A3. With the complete oxidation of 1 molecule of glucose, the amoeba produces ATP in the amount
1) 18 g/mol 3) 9 g/mol
2) 2 g/mol 4) 38 g/mol
1) amoeba proteus 3) trypanosome
2) green euglena 4) radiolaria
A5. Through the contractile vacuole in ciliates,
1) removal of solid waste products
2) excretion of liquid waste products
3) excretion of germ cells - gametes
4) gas exchange
1) mosquito blood 3) mosquito larvae
2) mosquito saliva 5) mosquito eggs
A7. Asexual reproduction of malarial plasmodium occurs in
1) human erythrocytes
2) erythrocytes and mosquito stomach
3) human leukocytes
4) erythrocytes and human liver cells
A8. Which of the organelles is absent in the cells of ciliates?
1) nucleus 3) mitochondria
2) chloroplasts 4) Golgi apparatus
A9. What do euglena and chlorella have in common?
1) the presence of glycogen in cells
2) the ability to photosynthesis
3) anaerobic respiration
4) the presence of flagella
A10. Not found among ciliates
1) heterotrophic organisms
2) aerobic organisms
3) autotrophic organisms
A11. The most complex
amoeba common 3) malarial plasmodium
euglena green 4) infusoria-shoe
A12. During cold weather, other unfavorable conditions, free-living protozoa
1) form colonies 3) form spores
2) actively move 4) form cysts
Part B
IN 1. Choose protozoa leading a free lifestyle
1) infusoria stentor 4) lamblia
2) amoeba proteus 5) stylonichia
3) trypanosoma 6) balantidia
IN 2. Match the representative of the protozoa with the trait that he has
Unicellular or Protozoa. General characteristic" class="img-responsive img-thumbnail">
Part FROM
C1. Why do aquarists grow ciliates in milk?
C2. Find the errors in the given text, correct them, indicate the numbers of the sentences in which they were made. 1. The simplest (single-celled) organisms live only in fresh waters. 2. The cell of the simplest is an independent organism, with all the functions of a living system. 3. Unlike the cells of multicellular organisms, the cells of all protozoa have the same shape. 4. The simplest feed on particles of solid food, bacteria. 5. Undigested food residues are removed through contractile vacuoles. 6. Some protozoa have chlorophyll-containing chromatophores and are capable of photosynthesis.
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For the first time, unicellular organisms were discovered to the human eye in the 1670s, thanks to the Dutch naturalist, endowed with a great passion for understanding the world, Anthony van Leeuwenhoek. It was he who first considered these "little animals" with the help of his incredible lenses. Their scientific study began later - and does not stop until now. Unicellular organisms live everywhere, including in conditions where other organisms cannot survive.
What are the distinguishing features inherent in unicellular?
1. Morphologically, unicellular are single cell. However, in terms of its functions, it is self-sufficient organism, which knows how to move in space, multiply, eat. The sizes of unicellular organisms vary from a few microns to several centimeters. A few years ago, multinuclear xenophyophores with a diameter of at least 10 centimeters were discovered in the Mariana Trench.
2. Liquid medium- the fundamental condition for the existence of unicellular. Moreover, this is not only a sea or a swamp, but also liquids inside the body of a person or other creatures.
3. Unicellular organisms master space and attract food closer with the help of prolegs(temporary, constantly changing outgrowths of ectoplasm, like an amoeba), flagella(thin, long organelles, filaments of cytoplasm located in the front of the body, like in green euglena) and cilia(multiple outgrowths of the cytoplasm throughout the body, like in ciliates). The flagella twist into the liquid like a corkscrew, and the cilia “pop” creating a wave motion.
4. Most unicellular - heterotrophs, that is, they feed on ready-made organic substances. Euglena green - mixotroph, but the colonial volvox - autotroph.
5. Irritability(the ability of a cell to change physico-chemical properties under the influence of environmental conditions), one of the basic properties of a living organism, manifests itself in protozoa taxis: reactions to any irritation. Unicellular organisms move either in the direction of the stimulus (for example, a fragment of food) or away from it.
6. reflexes unicellular do not have due to the lack of a nervous system.
8. With asexual reproduction of protozoa, unlike multicellular ones, there is no destruction nuclear envelope during cell division.
9. Of course, the simplest have mitochondria.
Significance of unicellular animals
1. Protozoa are eaten by larger invertebrates.
2. The external and internal skeletons of testate amoebae, foraminifera, radiolarians and other similar creatures have formed marine sedimentary rocks for hundreds of thousands of years, which people use in construction (for example, shell rock).
To the sub-kingdom Protozoa are unicellular animals. Some species form colonies.
The protozoan cell has the same structural scheme as the cell of a multicellular animal: it is limited by a membrane, the inner space is filled with cytoplasm, in which the nucleus (nuclei), organelles and inclusions are located.
The cell membrane in some species is represented by an outer (cytoplasmic) membrane, in others - by a membrane and a pellicle. Some groups of protozoa form a shell around themselves. The membrane has a structure typical of a eukaryotic cell: it consists of two layers of phospholipids, into which proteins “sink” to different depths.
The number of cores is one, two or more. The shape of the nucleus is usually rounded. The nucleus is bounded by two membranes, these membranes are permeated with pores. The internal content of the nucleus is the nuclear juice (karyoplasm), which contains chromatin and nucleoli. Chromatin consists of DNA and proteins and is an interphase form of the existence of chromosomes (decondensed chromosomes). The nucleolus is composed of rRNA and proteins and is the site where ribosome subunits are formed.
The outer layer of the cytoplasm is usually lighter and denser - ectoplasm, the inner - endoplasm.
In the cytoplasm there are organelles characteristic of both cells of multicellular animals, and organelles characteristic only of this group of animals. Organelles of protozoa, common with organelles of a multicellular animal cell: mitochondria (ATP synthesis, oxidation of organic substances), endoplasmic reticulum (transport of substances, synthesis of various organic substances, compartmentalization), Golgi complex (accumulation, modification, secretion of various organic substances, synthesis of carbohydrates and lipids , the site of formation of primary lysosomes), lysosomes (cleavage of organic substances), ribosomes (protein synthesis), cell center with centrioles (formation of microtubules, in particular, spindle microtubules), microtubules and microfilaments (cytoskeleton). Protozoan organelles, characteristic only for this group of animals: stigmas (light perception), trichocysts (protection), axtostyle (support), contractile vacuoles (osmoregulation), etc. Photosynthesis organelles found in plant flagellates are called chromatophores. The organelles of protozoan movement are represented by pseudopodia, cilia, and flagella.
Nutrition - heterotrophic; in plant flagellates - autotrophic, may be mixotrophic.
Gas exchange occurs through the cell membrane, the vast majority of protozoa are aerobic organisms.
The response to environmental influences (irritability) manifests itself in the form of taxis.
When adverse conditions occur, most protozoa form cysts. Encystation is a way of experiencing adverse conditions.
The main method of protozoan reproduction is asexual reproduction: a) division of the mother cell into two daughter cells, b) division of the mother cell into many daughter cells (schizogony), c) budding. Mitosis is the basis of asexual reproduction. In a number of species, the sexual process takes place - conjugation (ciliates) and sexual reproduction (sporozoans).
Habitats: marine and fresh waters, soil, plant, animal and human organisms.
Classification of protozoa
- Subkingdom Protozoa, or Unicellular (Protozoa)
- Type Sarcomastigophora (Sarcomastigophora)
- Subtype Flagellates (Mastigophora)
- Class Plant flagellates (Phytomastigophorea)
- Class Animal flagellates (Zoomastigophorea)
- Opalina subtype (Opalinata)
- Subtype Sarcodaceae (Sarcodina)
- Rhizopeda class (Rhizopoda)
- Class Radiolaria, or Beams (Radiolaria)
- Class Sunflowers (Heliozoa)
- Subtype Flagellates (Mastigophora)
- Type Apicomplexa (Apicomplexa)
- Perkinsea class
- Class Sporozoa (Sporozoea)
- Type of Myxosporidium (Myxozoa)
- Class Myxosporea (Myxosporea)
- Class Actinosporidia (Actinosporea)
- Type of Microsporidia (Microspora)
- Type of ciliates (Ciliophora)
- Class Ciliary ciliates (Ciliata)
- Class Sucking ciliates (Suctoria)
- Type Labyrinthula (Labirinthomorpha)
- Ascetosporidia type (Ascetospora)
- Type Sarcomastigophora (Sarcomastigophora)
The simplest appeared about 1.5 billion years ago.
The simplest belong to the primitive unicellular eukaryotes (superkingdom Eucariota). It is now generally accepted that eukaryotes evolved from prokaryotes. There are two hypotheses of the origin of eukaryotes from prokaryotes: a) successive, b) symbiotic. According to the successive hypothesis, membranous organelles arise gradually from the plasmalemma of prokaryotes. According to the symbiotic hypothesis (endosymbiotic hypothesis, symbiogenesis hypothesis), a eukaryotic cell arises as a result of a series of symbioses of several ancient prokaryotic cells.
The sub-kingdom of unicellular or protozoa includes the smallest creatures whose body consists of one cell. These cells are an independent organism with all its characteristic functions (metabolism, irritability, movement, reproduction).
The body of unicellular organisms can have a constant (infusoria-shoe, flagella) or a non-permanent form (amoeba). The main components of the body of protozoa - nucleus and cytoplasm. In the cytoplasm of protozoa, along with general cellular organelles (mitochondria, ribosomes, the Galji apparatus, etc.), there are special organelles (digestive and contractile vacuoles) that perform the functions of digestion, osmoregulation, and excretion. Almost all protozoa are able to actively move. The movement is carried out with prolegs(in amoeba and other rhizopods), flagella(euglena green) or cilia(ciliates). Protozoa are able to capture solid particles (amoeba), which is called phagocytosis. Most protozoa feed on bacteria and decaying organic matter. Food after swallowing is digested into digestive vacuoles. The function of selection in protozoa is performed contractile vacuoles, or special holes - powder(for ciliates).
The simplest live in fresh water, seas and soil. The vast majority of protozoa have the ability to encystment, that is, the formation of the dormant stage upon the onset of adverse conditions (lowering temperature, drying up of the reservoir) - cysts covered with a dense protective sheath. Cyst formation is not only an adaptation to survival under adverse conditions, but also to the spread of protozoa. Once in favorable conditions, the animal leaves the cyst shell, begins to feed and multiply.
Reproduction of protozoa occurs by cell division into two (asexual); many have sexual intercourse. In the life cycle, most protozoa alternate between asexual and sexual reproduction.
There are over 90,000 unicellular species. All of them are eukaryotes (have a separate nucleus), but are at the cellular level of organization.
Amoeba
A representative of the rhizopod class is amoeba ordinary. Unlike many protozoa, it does not have a permanent body shape. It moves with the help of pseudopods, which also serve to capture food - bacteria, unicellular algae, and some protozoa.
Surrounding the prey with pseudopods, the food is in the cytoplasm, where a digestive vacuole is formed around it. In it, under the influence of digestive juice coming from the cytoplasm, digestion occurs, as a result of which digestive substances are formed. They penetrate the cytoplasm, and undigested food residues are thrown out.
The amoeba breathes the entire surface of the body: oxygen dissolved in water directly penetrates into its body by diffusion, and carbon dioxide formed in the cell during respiration is released outside.
The concentration of dissolved substances in the body of the amoeba is greater than in water, so water continuously accumulates and its excess is excreted through contractile vacuole. This vacuole is also involved in the removal of decay products from the body. The amoeba reproduces by division. The nucleus divides in two, its two halves diverge, a constriction is formed between them, and then two independent, daughter cells arise from one mother cell.
Amoeba is a freshwater animal.
Euglena green
Another widespread species of protozoan animals lives in fresh water bodies - euglena green. It has a spindle shape, the outer layer of the cytoplasm is compacted and forms a shell that helps to maintain this shape.
From the front end of the body of the green euglena, a long thin flagellum departs, rotating which, the euglena moves in the water. In the cytoplasm of euglena there is a nucleus and several colored oval bodies - chromatophores containing chlorophyll. Therefore, in the light, Euglena feeds like a green plant (autotrophically). A light-sensitive eye helps to find the illuminated places of the euglena.
If Euglena is in the dark for a long time, then chlorophyll disappears and it passes to a heterotrophic mode of nutrition, that is, it feeds on ready-made organic substances, absorbing them from the water with the entire surface of the body. Respiration, reproduction, division in two, cyst formation in green euglena are similar to those in amoeba.
Volvox
Among the flagella there are colonial species, for example, volvox.
Its shape is spherical, the body consists of a gelatinous substance, in which individual cells are immersed - members of the colony. They are small, pear-shaped, have two flagella. Thanks to the coordinated movement of all flagella, Volvox moves. In a Volvox colony there are few cells capable of reproduction; from which daughter colonies are formed.
Infusoria shoe
In fresh water, another type of protozoa is often found - infusoria-shoe, which got its name because of the peculiarities of the shape of the cell (in the form of a shoe). The organelles of locomotion are cilia. The body has a constant shape, as it is covered with a dense shell. Infusoria-shoes have two nuclei: large and small.
big core regulates all life processes, small- plays an important role in the reproduction of shoes. The infusoria feeds on bacteria, algae and some protozoa. With vibrations cilia food gets into mouth opening, then - in throat, at the bottom of which digestive vacuoles where food is digested and nutrients are absorbed. Undigested residues are removed through a special organ - powder. The selection function is performed contractile vacuole.
It reproduces, like the amoeba, asexually, however, the sexual process is also characteristic of the ciliates-shoes. It consists in the fact that two individuals unite, an exchange of nuclear material occurs between them, after which they disperse (Fig. 73).
This type of sexual reproduction is called conjugation. Thus, among freshwater protozoa, the ciliate shoe has the most complex structure.
Irritability
Characterizing the simplest organisms, one should pay special attention to one more of their properties - irritability. The simplest do not have a nervous system, they perceive irritations of the entire cell and are able to respond to them with movement - taxis moving towards or away from the stimulus.
Protozoa living in sea water and soil and others
Soil protozoa are representatives of amoebae, flagellates and ciliates, which play an important role in the soil-forming process.
In nature, protozoa participate in the circulation of substances, perform a sanitary role; in food chains they are one of the first links, being food for many animals, in particular fish; take part in the formation of geological rocks, and their shells determine the age of individual geological rocks.
The main terms and concepts tested in the examination paper: amoeba, balantidia, flagellates, ciliates, coccidia, malarial plasmodium, digestive vacuole, sexual progress, powder, sarcodes, contractile vacuole, sporozoans, green euglena.
The body of the simplest animals consists of a single cell that performs all the functions of life. Representatives of this sub-kingdom have all the properties of an independent organism. Free-living protozoa have additional organelles for movement, nutrition, excretion, protection, etc. Some of these organelles are temporary (amoeba prolegs), some are permanent (euglena flagellum, ciliate cilia).
The role of protozoa in nature and human life:
- are indispensable participants in the circulation of substances and energy in ecosystems, acting as micro-consumers and decomposers;
- form geological deposits of limestone, chalk;
- are objects of scientific research;
Flagella class. Representatives of this class have a constant body shape, due to the presence of a compacted cell membrane.
Euglena green has a spindle-shaped body. The cell size is about 0.05 mm. Euglena moves with the help of a flagellum - a cytoplasmic outgrowth consisting of thin fibrils. At the front end is a light-sensitive eye. In the cytoplasm, in addition to all the organelles characteristic of animal cells, there are chromatophores containing chlorophyll. In the light, Euglena is capable of photosynthesis. Therefore, it is referred to as intermediate, between plants and animals, evolutionary forms. Euglena reproduces asexually by dividing in two along the longitudinal axis. Sexual reproduction is carried out by copulation(cell fusion).
Volvox belongs to the colonial forms of flagellates.
type of infusoria. Class ciliary infusoria. The type has about 6 thousand species.
Representatives - infusoria-shoe, infusoria-trumpeter.
Infusoria-shoe - an animal 0.1-0.3 mm in size.
Its cell membrane is covered with cilia that serve for movement. There are two nuclei in a cell vegetative , polyploid and generative , diploid. The oral recess on the body forms an oral funnel, passing into the cellular mouth, leading to throat. Formed in the throat digestive vacuoles that digest food. Undigested food remains are removed through the opening - powder .
The ciliate shoe has two contractile vacuoles located at opposite ends of the body. Through them, excess water and metabolic products are excreted.
Reproduction of ciliates occurs both asexually and sexually. During asexual reproduction, longitudinal cell division occurs. During the sexual process, a cytoplasmic bridge is formed between two ciliates. Polyploid (large) nuclei are destroyed, and diploid (small) nuclei are divided by meiosis with the formation of four haploid nuclei, three of which die, and the fourth is divided in half, but by mitosis. Two nuclei are formed. One is stationary and the other is migratory. Then between the ciliates there is an exchange of migrating nuclei. Then the stationary and migrating nuclei merge, the individuals disperse, and large and small nuclei are again formed in them.
