Features of plant, animal and fungal cells. Comparison of plant and animal cells: main similarities and differences

Similarities and differences in the structure of cells of plants, animals and fungi

Similarities in the structure of eukaryotic cells.

Now it is impossible to say with complete certainty when and how life arose on Earth. We also do not know exactly how the first living creatures on Earth ate: autotrophic or heterotrophic. But at present, representatives of several kingdoms of living beings coexist peacefully on our planet. Despite the great difference in structure and lifestyle, it is obvious that there are more similarities between them than differences, and they all probably have common ancestors who lived in the distant Archean era. The presence of common “grandfathers” and “grandmothers” is evidenced by a number of common features in eukaryotic cells: protozoa, plants, fungi and animals. These signs include:

General plan of the cell structure: the presence of a cell membrane, cytoplasm, nucleus, organelles;
- fundamental similarity of metabolic and energy processes in the cell;
- coding of hereditary information using nucleic acids;
- unity chemical composition cells;
- similar processes of cell division.

Differences in the structure of plant and animal cells.

In the process of evolution, due to the unequal conditions of existence of cells of representatives of different kingdoms of living beings, many differences arose. Let's compare the structure and vital activity of plant and animal cells (Table 4).

The main difference between the cells of these two kingdoms is the way they are nourished. Plant cells containing chloroplasts are autotrophs, that is, they themselves synthesize the organic substances necessary for life using light energy during the process of photosynthesis. Animal cells are heterotrophs, i.e. a source of carbon for the synthesis of their own organic matter for them are organic substances coming from food. These same nutrients, such as carbohydrates, serve as a source of energy for animals. There are exceptions, such as green flagellates, which are capable of photosynthesis in the light and feed on ready-made organic substances in the dark. To ensure photosynthesis, plant cells contain plastids that carry chlorophyll and other pigments.

Since a plant cell has a cell wall that protects its contents and ensures its constant shape, when dividing between daughter cells, a partition is formed, and an animal cell, which does not have such a wall, divides to form a constriction.

Features of fungal cells.

Thus, the separation of fungi into an independent kingdom, numbering more than 100 thousand species, is absolutely justified. Mushrooms originate either from ancient filamentous algae that have lost chlorophyll, i.e., from plants, or from some ancient heterotrophs unknown to us, i.e., animals.

1. How does a plant cell differ from an animal cell?
2. What are the differences in the division of plant and animal cells?
3. Why are mushrooms separated into an independent kingdom?
4. What do they have in common and what differences in structure and life can be identified by comparing mushrooms with plants and animals?
5. Based on what features can we assume that all eukaryotes had common ancestors?

Kamensky A. A., Kriksunov E. V., Pasechnik V. V. Biology 10th grade
Submitted by readers from the website

The science that studies the structure and function of cells - cytology .

Cells can differ from each other in shape, structure and function, although the basic structural elements of most cells are similar. Systematic groups of cells – prokaryotic And eukaryotic (superkingdoms prokaryotes and eukaryotes) .

Prokaryotic cells do not contain a true nucleus and a number of organelles (the kingdom of the crushed cell).
Eukaryotic cells contain a nucleus in which the hereditary apparatus of the organism is located (superkingdoms fungi, plants, animals).

Any organism develops from a cell.
This applies to organisms that were born as a result of both asexual and sexual methods of reproduction. That is why the cell is considered the unit of growth and development of the organism.

According to the method of nutrition and cell structure, they are distinguished kingdoms :

• Drobyanki;
• Mushrooms;
• Plants;
• Animals.

Bacterial cells (kingdom Drobyanka) have: a dense cell wall, one circular DNA molecule (nucleoid), ribosomes. These cells lack many organelles characteristic of eukaryotic plant, animal and fungal cells. Based on their feeding method, bacteria are divided into phototrophs, chemotrophs, and heterotrophs.

Fungal cells covered with a cell wall that differs in chemical composition from the cell walls of plants. It contains chitin, polysaccharides, proteins and fats as its main components. The reserve substance of fungal and animal cells is glycogen.

Plant cells contain: chloroplasts, leucoplasts and chromoplasts; they are surrounded by a dense cell wall of cellulose, and also have vacuoles with cell sap. All green plants are autotrophic organisms.

U animal cells no dense cell walls. They are surrounded cell membrane, through which the exchange of substances with the environment occurs.

THEMATIC TASKS

Part A

A1. Which of the following is consistent with the cell theory?
1) the cell is elementary unit heredity
2) the cell is a unit of reproduction
3) the cells of all organisms are different in their structure
4) the cells of all organisms have different chemical compositions

A2. Precellular life forms include:
1) yeast
2) penicillium
3) bacteria
4) viruses

A3. A plant cell differs from a fungal cell in structure:
1) cores
2) mitochondria
3) cell wall
4) ribosomes

A4. One cell consists of:
1) influenza virus and amoeba
2) mucor mushroom and cuckoo flax
3) planaria and volvox
4) green euglena and slipper ciliates

A5. Prokaryotic cells have:
1) core
2) mitochondria
3) Golgi apparatus
4) ribosomes

A6. The species of the cell is indicated by:
1) core shape
2) number of chromosomes
3) membrane structure
4) primary protein structure

A7. The role of cell theory in science is
1) opening of the cell nucleus
2) opening the cell
3) generalization of knowledge about the structure of organisms
4) discovery of metabolic mechanisms

Part B

IN 1. Select features characteristic only of plant cells
1) there are mitochondria and ribosomes
2) cell wall made of cellulose
3) there are chloroplasts
4) storage substance – glycogen
5) reserve substance – starch
6) the nucleus is surrounded by a double membrane

AT 2. Select the characteristics that distinguish the kingdom of Bacteria from the rest of the kingdoms of the organic world.
1) heterotrophic mode of nutrition
2) autotrophic method of nutrition
3) the presence of a nucleoid
4) absence of mitochondria
5) absence of a core
6) presence of ribosomes

VZ. Find a correspondence between the structural features of the cell and the kingdoms to which these cells belong

Part C

C1. Give examples eukaryotic cells, which do not have a core.
C2. Prove that cell theory generalized a number of biological discoveries and predicted new discoveries.

In addition to the features characteristic of prokaryotes and eukaryotes, the cells of plants, animals, fungi and bacteria also have a number of features. Thus, plant cells contain specific organelles - chloroplasts, which determine their ability to photosynthesize, whereas these organelles are not found in other organisms. Of course, this does not mean that other organisms are not capable of photosynthesis, since, for example, in bacteria it occurs on invaginations of the plasma membrane and individual membrane vesicles in the cytoplasm.

Plant cells, as a rule, contain large vacuoles filled with cell sap. They are also found in the cells of animals, fungi and bacteria, but have a completely different origin and perform different functions. The main reserve substance found in the form of solid inclusions in plants is starch, in animals and fungi it is glycogen, and in bacteria it is glycogen or volutin.

One more hallmark of these groups of organisms is the organization of the surface apparatus: the cells of animal organisms do not have a cell wall, their plasma membrane is covered only with a thin glycocalyx, while all others have it. This is entirely understandable, since the way animals feed is associated with capturing food particles in the process of phagocytosis, and the presence of a cell wall would deprive them of this opportunity. The chemical nature of the substance that makes up the cell wall is different in various groups living organisms: if in plants it is cellulose, then in fungi it is chitin, and in bacteria it is murein. Comparative characteristics structure of cells of plants, animals, fungi and bacteria

Differences in the structure of representatives' cells different kingdoms wildlife are shown in the figure.

Chemical composition of the cell. Macro- and microelements. The relationship between the structure and functions of inorganic and organic substances (proteins, nucleic acids, carbohydrates, lipids, ATP) that make up the cell. Role chemical substances in the human cell and body

Chemical composition of the cell

Most chemical elements have been found in living organisms Periodic table elements discovered by D.I. Mendeleev to date. On the one hand, they do not contain a single element that would not exist in inanimate nature, and on the other hand, their concentrations in bodies inanimate nature and living organisms differ significantly.

These chemical elements form inorganic and organic substances. Despite the fact that inorganic substances predominate in living organisms, it is organic substances that determine the uniqueness of their chemical composition and the phenomenon of life as a whole, since they are synthesized mainly by organisms in the process of life and play a vital role in reactions.

The study of the chemical composition of organisms and chemical reactions flowing in them, science studies biochemistry.

It should be noted that the content of chemicals in different cells and tissues can vary significantly. For example, if in animal cells proteins predominate among organic compounds, then in plant cells carbohydrates predominate.

Macro- and microelements

About 80 chemical elements are found in living organisms, but only 27 of these elements have their functions in the cell and organism established. The remaining elements are present in small quantities and, apparently, enter the body with food, water and air. The content of chemical elements in the body varies significantly. Depending on their concentration, they are divided into macroelements and microelements.

The concentration of each macronutrients in the body exceeds 0.01%, and their total content is 99%. Macroelements include oxygen, carbon, hydrogen, nitrogen, phosphorus, sulfur, potassium, calcium, sodium, chlorine, magnesium and iron. The first four of the listed elements (oxygen, carbon, hydrogen and nitrogen) are also called organogenic, since they are part of the main organic compounds. Phosphorus and sulfur are also components of a number of organic substances, such as proteins and nucleic acids. Phosphorus is essential for the formation of bones and teeth.

Without the remaining macronutrients it is impossible normal functioning body. Thus, potassium, sodium and chlorine are involved in the processes of cell excitation. Potassium is also necessary for the functioning of many enzymes and the retention of water in the cell. Calcium is found in the cell walls of plants, bones, teeth and shellfish and is required for contraction muscle cells, as well as for intracellular movement. Magnesium is a component of chlorophyll, a pigment that ensures photosynthesis occurs. It also takes part in protein biosynthesis. Iron, in addition to being part of hemoglobin, which carries oxygen in the blood, is necessary for the processes of respiration and photosynthesis, as well as for the functioning of many enzymes.

Microelements are contained in the body in concentrations of less than 0.01%, and their total concentration in the cell does not reach 0.1%. Microelements include zinc, copper, manganese, cobalt, iodine, fluorine, etc. Zinc is part of the molecule of the pancreatic hormone - insulin, copper is required for the processes of photosynthesis and respiration. Cobalt is a component of vitamin B12, the absence of which leads to anemia. Iodine is necessary for hormone synthesis thyroid gland, ensuring normal metabolism, and fluoride is associated with the formation of tooth enamel.

Both deficiency and excess or disruption of the metabolism of macro- and microelements lead to the development various diseases. In particular, a lack of calcium and phosphorus causes rickets, a lack of nitrogen - severe protein deficiency, a deficiency of iron - anemia, and a lack of iodine - a violation of the formation of thyroid hormones and a decrease in metabolic rate. A decrease in fluoride intake from water and food largely determines the disruption of tooth enamel renewal and, as a consequence, a predisposition to caries. Lead is toxic to almost all organisms. Its excess causes irreversible damage to the brain and central nervous system which is manifested by loss of vision and hearing, insomnia, renal failure, seizures, and can also lead to paralysis and diseases such as cancer. Acute poisoning lead is accompanied by sudden hallucinations and ends in coma and death.

The lack of macro- and microelements can be compensated by increasing their content in food and drinking water, as well as due to the reception medicines. Thus, iodine is found in seafood and iodized salt, calcium - in eggshells and so on.

The relationship between the structure and functions of inorganic and organic substances (proteins, nucleic acids, carbohydrates, lipids, ATP) that make up the cell. The role of chemicals in the cell and human body

Inorganic substances

Chemical elements cells form various compounds - inorganic and organic. The inorganic substances of the cell include water, mineral salts, acids, etc., and the organic substances include proteins, nucleic acids, carbohydrates, lipids, ATP, vitamins, etc.

Water(H 2 O) is the most common inorganic substance of the cell, which has unique physical and chemical properties. It has no taste, no color, no smell. The density and viscosity of all substances is assessed using water. Like many other substances, water can exist in three states of aggregation: solid (ice), liquid and gaseous (steam). The melting point of water is 0°C, the boiling point is 100°C, however, the dissolution of other substances in water can change these characteristics. The heat capacity of water is also quite high - 4200 kJ/mol K, which gives it the opportunity to take part in thermoregulation processes. In a water molecule, the hydrogen atoms are located at an angle of 105°, while the total electron pairs are pulled away by the more electronegative oxygen atom. This determines the dipole properties of water molecules (one end is positively charged and the other negatively charged) and the possibility of the formation of hydrogen bonds between water molecules. The cohesion of water molecules underlies the phenomenon of surface tension, capillarity and the properties of water as a universal solvent. As a result, all substances are divided into those soluble in water (hydrophilic) and insoluble in it (hydrophobic). Thanks to these unique properties It is predetermined that water has become the basis of life on Earth.

The average water content in the body's cells varies and may change with age. Thus, in a one-and-a-half-month-old human embryo, the water content in the cells reaches 97.5%, in an eight-month-old - 83%, in a newborn it decreases to 74%, and in an adult it averages 66%. However, body cells differ in their water content. So, the bones contain about 20% water, the liver - 70%, and the brain - 86%. In general it can be said that the concentration of water in cells is directly proportional to the metabolic rate.

Mineral salts can be in dissolved or undissolved states. Soluble salts dissociate into ions - cations and anions. The most important cations are potassium and sodium ions, which facilitate the transport of substances across the membrane and are involved in the occurrence and conduct nerve impulse; as well as calcium ions, which takes part in contraction processes muscle fibers and blood clotting; magnesium, which is part of chlorophyll; iron, which is part of a number of proteins, including hemoglobin. The most important anions are the phosphate anion, which is part of ATP and nucleic acids, and the carbonic acid residue, which softens fluctuations in the pH of the environment. Ions of mineral salts ensure the penetration of water itself into the cell and its retention in it. If the salt concentration in the environment is lower than in the cell, then water penetrates into the cell. Ions also determine the buffering properties of the cytoplasm, i.e. its ability to maintain a constant slightly alkaline pH of the cytoplasm, despite the constant formation of acidic and alkaline products in the cell.

Insoluble salts(CaCO 3, Ca 3 (PO 4) 2, etc.) are part of the bones, teeth, shells and shells of unicellular and multicellular animals.

In addition, organisms can produce other inorganic compounds, such as acids and oxides. Thus, the parietal cells of the human stomach produce hydrochloric acid, which activates digestive enzyme pepsin, and silicon oxide permeates the cell walls of horsetails and forms the shells of diatoms. IN last years The role of nitric oxide (II) in signaling in cells and the body is also being explored.

Organic matter

All living things on our planet are made up of cells. The cellular structure of all living beings is the basis of the kinship of all living things that exist on our planet. But there are many significant differences between the cells of plants, fungi, bacteria and animals. To understand how they are similar and how they differ, you need to consider in detail the structure of each type of cell.

How are bacteria different from other organisms?

The main thing that distinguishes bacteria (prokaryotes) from other living organisms (eukaryotes) is that they are the oldest creatures on the planet, which do not have a formed nucleus.

All prokaryotes consist of:

• capsules that perform a protective function;
• nuclear substance in which genetic data is stored;
• cytoplasm, which provides communication between organelles;
• , which ensures the preservation of shape and is responsible for the regulation of gases and water;
• flagella, thanks to which bacteria can move.

Since single-celled bacteria do not have a formed nucleus, its functions are performed by a nucleoid, which stores DNA and all genetic data. A nucleoid is a region of the cytoplasm that stores genetic information about an organism.

Cytoplasm is a liquid that contains nutrients necessary for life and a large number of squirrel. Also located in the cytoplasm are ribosomes that synthesize protein.

The capsule is located on top of the shell and from unfavorable external influences, for example, from drying out and damage.

One of the features cellular structure prokaryotes is that when exposed to external factors they can change their shape. Moreover, they are able to take their original form immediately as soon as the influence of external unfavorable factors ceases. This process is called sporulation.

Cellular structure of plants, fungi and animals

All animals, fungi and plants have much in common in their structure. As part of their cells, they all have:

• core;
• mitochondria;
• cytoplasmic membrane;
• endoplasmic reticulum;
• cytoplasm;
• Golgi apparatus.

The nucleus is the main and largest element of the cell, which is responsible for its vital functions. It contains the DNA of a plant or animal, and the synthesis of RNA and ribosomes occurs. The shape of the nucleus in all organisms is most often spherical.

The cytoplasmic membrane protects the contents from external influences. It has pores through which nutrients and water enter. The pores also remove waste products.

Plant cells are distinguished by the presence of plastids, which are located in chloroplasts, leucoplasts and chromoplasts. Chromoplasts contain substances that color fruits and stems. Most often they are yellow, red or orange in color. Due to their bright colors, plant flowers attract the attention of pollinating insects, such as bees. Leucoplasts contain a reserve nutrients, which are used when the body is in unfavorable conditions. Chloroplasts are plastids that are colored green color, which are responsible for the process of photosynthesis. Chloroplasts are found only in leaves or stems.

The cell wall of plants consists of cellulose, of fungi - of chitin, and in animals it is absent altogether. At the same time, animal and fungal cells store glycogen, while plant cells store starch.

The Golgi apparatus is responsible for the production and accumulation of polysaccharides and complex proteins.

Number of vacuoles in animals and plant cells varies. Plants have one large vacuole, and animals have one or more small ones. Plant vacuoles are responsible for the entry and exit of water, while animals retain water, ions, and store waste products. Fungi have no vacuoles at all.

A feature of fungal cells is that they usually have more than one nucleus. Under a microscope, you can see from 1 to 30 nuclei.

General and excellent

As mentioned above, the structure of prokaryotes differs from others in that they are nuclear-free and are significantly smaller in size than other living beings. You'll need a fairly powerful microscope to see them.

Very for a long time ancient scientists mistakenly classified mushrooms in the same group as plants. And this was done only because of their external similarity. After all, mushrooms, like plants, cannot move. And at first glance they don’t look like animals at all. However, once scientists were able to examine the cells, they discovered that a fungal cell is very similar to an animal cell. Therefore, these living organisms are no longer classified as plants. However, they cannot be classified as animals either, since a fungal cell, in addition to similarities, also has a number of differences from an animal cell. In this regard, mushrooms were separated into a separate kingdom. Thus, in nature there are five kingdoms of living organisms: animals, plants, fungi, bacteria and viruses.

Main features of a mushroom cell

Fungi are eukaryotes. These are living organisms whose cells contain a nucleus. It is necessary in order to protect the genetic information recorded on DNA. Eukaryotes, in addition to fungi, are animals and plants.

In addition, a vacuole may be present in an old fungal cell. All of the organelles listed above perform their functions. Let's look at them briefly.

Unlike plants, fungal cells do not contain plastids. In plants, these organelles are responsible for photosynthesis (chloroplasts) and petal coloring (chromoplasts). Fungi also differ from plants in that in their case only the old cell has a vacuole. Plant cells possess this organelle throughout their entire life cycle.

Mushroom core

Since they are eukaryotes, each cell contains a nucleus. It is designed to protect the genetic information recorded on DNA, as well as to coordinate all processes occurring in the cell.

This structure has a nuclear membrane in which there are special pores consisting of special proteins - nucleoprions. Thanks to the pores, the nucleus can exchange substances with the cytoplasm.

The environment that is inside the membrane is called karyoplasm. It contains DNA in the form of chromosomes.

Unlike plants and animals, whose cells usually contain one nucleus (an exception may be, for example, multinucleated muscle cells or anucleated platelets), a fungal cell often has not one, but two or more nuclei.

Conclusion - variety of mushrooms

So, when we have already figured out how the cell of these organisms works, let's briefly look at their varieties.

Multicellular fungi, depending on their structure, are divided into the following classes: basidiomycetes, ascomycetes, oomycetes, zygomycetes and chytridiomycetes.