How a cell is formed. The structure of the cell under the electron microscope. Similarities between plant and animal cells

All cellular life forms on earth can be divided into two kingdoms based on the structure of their constituent cells - prokaryotes (prenuclear) and eukaryotes (nuclear). Prokaryotic cells are simpler in structure, apparently, they arose earlier in the process of evolution. Eukaryotic cells - more complex, arose later. The cells that make up the human body are eukaryotic.

Despite the variety of forms, the organization of the cells of all living organisms is subject to uniform structural principles.

prokaryotic cell

eukaryotic cell

The structure of a eukaryotic cell

Animal cell surface complex

Comprises glycocalyx, plasmalemma and the underlying cortical layer of the cytoplasm. The plasma membrane is also called the plasmalemma cell membrane. It is a biological membrane, about 10 nanometers thick. Provides primarily a delimiting function in relation to the environment external to the cell. In addition, it performs a transport function. The cell does not waste energy on maintaining the integrity of its membrane: the molecules are held according to the same principle by which fat molecules are held together - it is thermodynamically more advantageous for the hydrophobic parts of the molecules to be located in close proximity to each other. The glycocalyx consists of molecules of oligosaccharides, polysaccharides, glycoproteins and glycolipids "anchored" in the plasmalemma. The glycocalyx performs receptor and marker functions. The plasma membrane of animal cells mainly consists of phospholipids and lipoproteins interspersed with protein molecules, in particular, surface antigens and receptors. In the cortical (adjacent to the plasma membrane) layer of the cytoplasm there are specific elements of the cytoskeleton - actin microfilaments ordered in a certain way. The main and most important function of the cortical layer (cortex) is pseudopodial reactions: ejection, attachment and reduction of pseudopodia. In this case, the microfilaments are rearranged, lengthened or shortened. The shape of the cell (for example, the presence of microvilli) also depends on the structure of the cytoskeleton of the cortical layer.

The structure of the cytoplasm

The liquid component of the cytoplasm is also called the cytosol. Under a light microscope, it seemed that the cell was filled with something like a liquid plasma or sol, in which the nucleus and other organelles “float”. Actually it is not. The internal space of a eukaryotic cell is strictly ordered. The movement of organelles is coordinated with the help of specialized transport systems, the so-called microtubules, which serve as intracellular "roads" and special proteins dyneins and kinesins, which play the role of "engines". Separate protein molecules also do not freely diffuse throughout the entire intracellular space, but are directed to the necessary compartments using special signals on their surface, recognized by the cell's transport systems.

Endoplasmic reticulum

In a eukaryotic cell, there is a system of membrane compartments (tubes and tanks) passing into each other, which is called the endoplasmic reticulum (or endoplasmic reticulum, EPR or EPS). That part of the ER, to the membranes of which ribosomes are attached, is referred to as granular(or rough) to the endoplasmic reticulum, protein synthesis occurs on its membranes. Those compartments that do not have ribosomes on their walls are classified as smooth(or agranular) EPR, which is involved in the synthesis of lipids. Interior spaces smooth and granular EPR are not isolated, but pass into each other and communicate with the lumen of the nuclear membrane.

golgi apparatus

Nucleus

cytoskeleton

Centrioles

Mitochondria

Comparison of pro- and eukaryotic cells

The most important difference between eukaryotes and prokaryotes for a long time the presence of a formed nucleus and membrane organelles was considered. However, by the 1970s and 1980s it became clear that this was only a consequence of deeper differences in the organization of the cytoskeleton. For some time it was believed that the cytoskeleton is characteristic only of eukaryotes, but in the mid-1990s. proteins homologous to the major proteins of the eukaryotic cytoskeleton have also been found in bacteria.

It is the presence of a specifically arranged cytoskeleton that allows eukaryotes to create a system of mobile internal membrane organelles. In addition, the cytoskeleton allows for endo- and exocytosis (it is assumed that it is due to endocytosis that intracellular symbionts, including mitochondria and plastids, appeared in eukaryotic cells). Other essential function eukaryotic cytoskeleton - ensuring the division of the nucleus (mitosis and meiosis) and the body (cytotomy) of the eukaryotic cell (the division of prokaryotic cells is organized more simply). Differences in the structure of the cytoskeleton also explain other differences between pro- and eukaryotes - for example, the constancy and simplicity of the forms of prokaryotic cells and the significant diversity of the form and the ability to change it in eukaryotic, as well as relatively big sizes the latter. So, the size of prokaryotic cells averages 0.5-5 microns, the sizes of eukaryotic cells - on average from 10 to 50 microns. In addition, only among eukaryotes come across truly giant cells, such as massive eggs of sharks or ostriches (in a bird's egg, the entire yolk is one huge egg), neurons of large mammals, whose processes, reinforced by the cytoskeleton, can reach tens of centimeters in length.

Anaplasia

The destruction of the cellular structure (for example, in malignant tumors) is called anaplasia.

History of cell discovery

The first person to see cells was the English scientist Robert Hooke (known to us thanks to Hooke's law). In a year, trying to understand why the cork tree swims so well, Hooke began to examine thin sections of cork with the help of a microscope he had improved. He found that the cork was divided into many tiny cells, which reminded him of monastic cells, and he called these cells cells (in English, cell means "cell, cell, cell"). In the year, the Dutch master Antony van Leeuwenhoek (Anton van Leeuwenhoek, -) using a microscope for the first time saw "animals" in a drop of water - moving living organisms. Thus, by the beginning of the 18th century, scientists knew that under high magnification plants had a cellular structure, and they saw some organisms, which were later called unicellular. However, the cellular theory of the structure of organisms was formed only by the middle of the 19th century, after more powerful microscopes appeared and methods for fixing and staining cells were developed. One of its founders was Rudolf Virchow, however, there were a number of errors in his ideas: for example, he assumed that cells are weakly connected to each other and each exists “by itself”. Only later was it possible to prove the integrity of the cellular system.

The structural unit of any organism is the cell. The definition of this structure was first used when he studied the structure of tissues under a microscope. Scientists have now found a large number of various types of cells found in nature. The only organisms non-cellular structure are viruses.

Cell: definition, structure

A cell is a structural and morphofunctional unit of all living organisms. Distinguish between unicellular and multicellular organisms.

Most cells have the following structures: integumentary apparatus, nucleus and cytoplasm with organelles. Covers can be represented by a cytoplasmic membrane and a cell wall. Only the eukaryotic cell has a nucleus and organelles, the definition of which differs from that of a prokaryotic cell.

Cells of multicellular organisms form tissues, which, in turn, are a component of organs and organ systems. They are different sizes and may differ in form and function. These small structures can only be distinguished with a microscope.

in biology. Definition of a prokaryotic cell

Microorganisms such as bacteria are a prime example of prokaryotic organisms. This type of cell is simple in structure, because bacteria lack a nucleus and other cytoplasmic organelles. microorganisms is enclosed in a specialized structure - a nucleoid, and the functions of organelles are performed by mesosomes, which are formed by protrusion of the cytoplasmic membrane into the cell.

What other features does the definition say that the presence of cilia and flagella is also hallmark bacteria. This extra locomotor apparatus differs from different groups microorganisms: someone has only one flagellum, someone has two or more. Ciliates do not have flagella, but cilia are present along the entire periphery of the cell.

Inclusions play an important role in the life of bacteria, because prokaryotic cells do not have organelles that can accumulate necessary substances. Inclusions are located in the cytoplasm and are compacted there. If necessary, bacteria can use these accumulated substances for their needs in order to maintain normal life.

eukaryotic cell

Evolutionarily more advanced than prokaryotic cells. They have all the typical organelles, as well as the nucleus - the center for storing and transmitting genetic information.

The definition of the term "cell" accurately describes the structure of eukaryotes. Each cell is covered with a cytoplasmic membrane, which is represented by a bilipid layer and proteins. Above is the glycocalyx, which is formed by glycoproteins and performs a receptor function. Plant cells also have a cell wall.

The cytoplasm of eukaryotes is represented by a colloidal solution containing organelles, a cytoskeleton, and various inclusions. Organoids include the endoplasmic reticulum (smooth and rough), lysosomes, peroxisomes, mitochondria, and plant plastids. The cytoskeleton is represented by microtubules, microfilaments and intermediate microfilaments. These structures form a scaffold and are also involved in division. The center, which any animal cell has, plays a direct role in this process. Determination, finding the cytoskeleton and the cell center in its thickness is possible only with the use of a powerful modern microscope.

The nucleus is a two-membrane structure, the contents of which are represented by karyolymph. It contains the chromosomes containing the DNA of the entire cell. The nucleus is responsible for transcription of the body's genes, and also controls the stages of division during mitosis, amitosis, and meiosis.

non-cellular life forms

What is a term cell can be used to describe the structure of almost any organism, but there are exceptions. Thus, viruses are the main representatives of non-cellular forms of life. Their organization is quite simple, because viruses are infectious agents that contain only two organic components in their composition: DNA or RNA, as well as a protein coat.

Bacteria are also attacked by viruses that make up the bacteriophage group. Their body is shaped like a dodecahedron, and the "injection" of nucleic acid into bacterial cell occurs with the help of the caudal process, represented by the contractile sheath, the inner rod and the basal plate.

We can say that living organisms are a complex system that performs various functions necessary for normal life. They are made up of cells. Therefore, they are divided into multicellular and unicellular. It is the cell that forms the basis of any organism, regardless of its structure.

Unicellular organisms have only one. Multicellular living organisms are represented different types cells that differ in their functional significance. Cytology is the study of cells, which includes the science of biology.

The structure of the cell is almost the same for any of their types. They differ in function, size and shape. Chemical composition is also typical for all cells of living organisms. The cell contains the main molecules: RNA, proteins, DNA and elements of polysaccharides and lipids. Almost 80 percent of a cell is made up of water. In addition, it contains sugars, nucleotides, amino acids and other products of processes occurring in the cell.

The structure of a cell of a living organism consists of many components. The surface of the cell is a membrane. It allows the cell to penetrate only certain substances. Between the cell and the membrane is liquid. It is the membrane that mediates in metabolic processes occurring between the cell and the interstitial fluid.

The main component of the cell is the cytoplasm. It is a viscous, semi-liquid substance. It contains organelles that perform a number of functions. These include the following components: cell center, lysosomes, nucleus, mitochondria, endoplasmic reticulum, ribosomes and the Golgi complex. Each of these components is necessarily included in the structure of the cell.

The entire cytoplasm consists of many tubules and cavities, which are the endoplasmic reticulum. This whole system synthesizes, accumulates and promotes organic compounds that the cell produces. The endoplasmic reticulum is also involved in protein synthesis.

In addition to it, ribosomes, which contain RNA and protein, take part in protein synthesis. The Golgi complex affects the formation of lysosomes and accumulates. These are special cavities with vesicles at the ends.

The cell center contains two bodies involved in the Cell center is located directly near the nucleus.

So gradually we got to the main component in the structure of the cell - the nucleus. This is the most main part cells. It contains the nucleolus, proteins, fats, carbohydrates and chromosomes. The entire interior of the nucleus is filled with nuclear juice. All information about heredity is contained in the cells of the human body provides for the presence of 46 chromosomes. Sex cells consist of 23 chromosomes.

Cells also contain lysosomes. They cleanse the cell of dead particles.
Cells, in addition to the main components, also contain some organic and inorganic compounds. As already mentioned, the cell consists of 80 percent of the water. Another inorganic compound that is part of its composition are salts. Water plays important role in the life of the cell. It is the main participant in chemical reactions, as a carrier of substances and the removal of harmful compounds from the cell. Salts contribute to the proper distribution of water in the cell structure.

Among organic compounds present: hydrogen, oxygen, sulfur, iron, magnesium, zinc, nitrogen, iodine, phosphorus. They are vital for conversion into complex organic compounds.

The cell is the main component of any living organism. Its structure is complex mechanism, which should not have any failures. Otherwise, it will result in immutable processes.

A cell (cellula) is a living system consisting of two parts - the cytoplasm and the nucleus, which are the basis of the structure, development and life of all animal and plant organisms (Fig. 5, 6). Cells combined with extracellular structures form tissues. The control and relationship of cells that are part of tissues is established nervous system and hormones. Adhesion (adhesion) of cells ensures the structural and functional unity of tissues. The development of cell structure in phylogenesis had great importance in the evolution of organic life. Thanks to cell structure reproduction, growth and transfer of hereditary properties to new organisms, restoration of organs and tissues (regeneration) are possible. The cells of each tissue have different shape: plates, cubes, cylinders, balls, spindles or even pass without clear boundaries into each other (syncytium). These forms are often depicted from cells that are densified (fixed) chemicals. In fact, living cells have uneven contours with numerous protrusions and processes, which are very dynamic formations.

5. Scheme of the submicroscopic structure of a fixed cell. 1 - cell membrane; 2 - hyaloplasm; 3 - intracellular threads; 4 - lipoid granules; 5 - ergastoplasm and in it: 6 - alpha cytomembranes; 7- ribosomes; 8 - cores; 9 - pores in the nuclear envelope; 10 - nuclear envelope; 11 - nucleolus; 12 - intracellular mesh apparatus; 13 - mitochondria; 14 centrioles.

6. Scheme of the structure of a fixed cell under light microscopy. 1 - cell membrane; 2 - cytoplasm; 3 - intracellular mesh apparatus; 4 - cell center; 5 - mitochondria; 6 - protein granules; 7 - core with shell; 8 - lumps of chromatin; 9 - nucleolus; 10 - vacuoles; 11 - lipoid granules.

The cell consists of a nucleus and cytoplasm. The nucleus (nucleus) has a spherical ovoid shape and contains chromosomes that are well expressed in the phase of cell division and are not visible in the interphase nuclei. The nucleus consists of: a) chromatin, which has the form of lumps or threads. Nuclear deoxyribonucleic acid (DNA) is localized in chromatin and is associated only with chromosomes, which during mitotic division are helically twisted into chromonemes. During the interphase period, the chromosomes straighten out and their thinnest threads are visible only with electron microscopy; b) karyolymph (nuclear juice) - an environment where swollen despiralized chromosomes, nucleoli and globulins are localized; c) nucleoli that synthesize ribonucleic acid (RNA), which penetrates into the cytoplasm through the pores of the nuclear envelope. They consist of ribonucleoprotein and RNA granules. The nucleoli disappear during nuclear division. In cells that actively synthesize protein, there are large nucleoli with great content RNA; d) the nuclear envelope, consisting of two membranes pierced through holes through which the karyolymph communicates with the cytoplasm.

For the most part, there is one nucleus in the cells, except for mature erythrocytes, where the nucleus is absent; there are cells with two, three and hundreds of nuclei. The function of the nucleus is more active between cell divisions. Chemical structure the nucleus consists of DNA, RNA, salts of Mg, Na, K, Ca, precursors of nucleic acids-nucleotides and nuclear proteins: a) histones associated with DNA; b) globulins connected with nuclear enzymes of nucleic metabolism and anaerobic glycolysis; c) non-histone proteins associated with RNA; d) insoluble proteins.

The cytoplasm is the basis where various organelles and inclusions are located in the main substance of the cell, which is a structureless globular hyaloplasm.

Organelles. Microtubules are three-layer formations that serve as supporting elements for other organelles and cell inclusions. Ribosomes are particles of protein, RNA, Mg salts and polyamines in the form of granules, free and attached to the membrane of the ergastoplasmic reticulum. Ribosomes synthesize proteins. Ergastoplasmic (endoplasmic) reticulum consists of vacuolated elements various forms. Ribosome granules are attached to the outer membrane of this network. The network is extremely dynamic, easily rebuilt with external influences into spherical, saccular, lamellar formations. The ergastoplasmic reticulum is involved in the synthesis of proteins and in the conduction of excitation inside the cell. The Golgi complex has a network structure, located near the nucleus and surrounding the cell center. Represents flattened sacs or cisterns containing secretion products of the ergastoplasmic complex. Lysosomes are spherical particles containing about 12 hydrolytic enzymes. Mitochondria have the form of filamentous formations consisting of two-layer membranes. In the center of the mitochondria are cristae (ridges), which are derivatives of the inner layer. Mitochondria are involved in the oxidation of substances. The cell center is located near the nucleus and has the form of cylindrical tubes called centrioles. During mitotic cell division, centrioles orient chromosomes along the poles of the cell. Specialized structures of the cytoplasm are microvilli, cilia, flagella, myofibrils, neurofibrils, tonofibrils.

Inclusions. In the process of metabolism in the cell are deposited various substances type of protein, lipid, carbohydrate, pigment granules.

Animal and plant cells, both multicellular and unicellular, are in principle similar in structure. Differences in the details of the structure of cells are associated with their functional specialization.

The main elements of all cells are the nucleus and cytoplasm. The core has complex structure, changing to different phases cell division, or cycle. The nucleus of a nondividing cell occupies approximately 10–20% of its total volume. It consists of a karyoplasm (nucleoplasm), one or more nucleoli (nucleolus) and a nuclear envelope. Karyoplasm is a nuclear juice, or karyolymph, in which there are chromatin threads that form chromosomes.

The main properties of the cell:

• metabolism
• sensitivity
• ability to reproduce

The cell lives in internal environment body - blood, lymph and tissue fluid. The main processes in the cell are oxidation, glycolysis - the breakdown of carbohydrates without oxygen. Cell permeability is selective. It is determined by the response to high or low concentration salts, phago- and pinocytosis. Secretion - the formation and secretion by cells of mucus-like substances (mucin and mucoids), which protect against damage and participate in the formation of intercellular substance.

Types of cell movements:

1. amoeboid (false legs) - leukocytes and macrophages.
2. sliding - fibroblasts
3. flagellate type - spermatozoa (cilia and flagella)

Cell division:

1. indirect (mitosis, karyokinesis, meiosis)
2. direct (amitosis)

During mitosis, the nuclear substance is distributed evenly between daughter cells, because The chromatin of the nucleus is concentrated in chromosomes, which split into two chromatids, diverging into daughter cells.

Structures of a living cell

Chromosomes

Mandatory elements of the nucleus are chromosomes that have a specific chemical and morphological structure. They take an active part in the metabolism in the cell and are directly related to the hereditary transmission of properties from one generation to another. However, it should be borne in mind that, although heredity is provided by the whole cell as unified system, nuclear structures, namely chromosomes, occupy special place. Chromosomes, unlike cell organelles, are unique structures characterized by a constant qualitative and quantitative composition. They cannot interchange each other. An imbalance in the chromosome set of a cell ultimately leads to its death.

Cytoplasm

The cytoplasm of a cell exhibits a very complex structure. The introduction of the technique of thin sections and electron microscopy made it possible to see the fine structure of the underlying cytoplasm. It has been established that the latter consists of parallel arranged complex structures in the form of plates and tubules, on the surface of which there are the smallest granules with a diameter of 100–120 Å. These formations are called the endoplasmic complex. This complex includes various differentiated organelles: mitochondria, ribosomes, the Golgi apparatus, in the cells of lower animals and plants - the centrosome, in animals - lysosomes, in plants - plastids. In addition, a number of inclusions are found in the cytoplasm that take part in the metabolism of the cell: starch, fat droplets, urea crystals, etc.

Membrane

The cell is surrounded by a plasma membrane (from Latin "membrane" - skin, film). Its functions are very diverse, but the main one is protective: it protects the internal contents of the cell from the effects of the external environment. Due to various outgrowths, folds on the surface of the membrane, the cells are firmly interconnected. The membrane is permeated with special proteins through which certain substances necessary for the cell or to be removed from it can move. Thus, the exchange of substances is carried out through the membrane. Moreover, what is very important, substances are passed through the membrane selectively, due to which the required set of substances is maintained in the cell.

In plants, the plasma membrane is covered on the outside with a dense membrane consisting of cellulose (fiber). The shell performs protective and reference function. It serves as the outer frame of the cell, giving it a certain shape and size, preventing excessive swelling.

Nucleus

Located in the center of the cell and separated by a two-layer membrane. It has a spherical or elongated shape. The shell - the karyolemma - has pores necessary for the exchange of substances between the nucleus and the cytoplasm. The contents of the nucleus are liquid - karyoplasm, which contains dense bodies - nucleoli. They are granular - ribosomes. The bulk of the nucleus - nuclear proteins - nucleoproteins, in the nucleoli - ribonucleoproteins, and in the karyoplasm - deoxyribonucleoproteins. The cell is covered cell wall, which consists of protein and lipid molecules having a mosaic structure. The membrane ensures the exchange of substances between the cell and the intercellular fluid.

EPS

This is a system of tubules and cavities, on the walls of which there are ribosomes that provide protein synthesis. Ribosomes can also be freely located in the cytoplasm. There are two types of ER - rough and smooth: on the rough ER (or granular) there are many ribosomes that carry out protein synthesis. Ribosomes give membranes a rough appearance. Smooth ER membranes do not carry ribosomes on their surface; they contain enzymes for the synthesis and breakdown of carbohydrates and lipids. Smooth EPS looks like a system of thin tubes and tanks.

Ribosomes

Small bodies with a diameter of 15–20 mm. Carry out the synthesis of protein molecules, their assembly from amino acids.

Mitochondria

These are two-membrane organelles, the inner membrane of which has outgrowths - cristae. The contents of the cavities is the matrix. Mitochondria contain a large number of lipoproteins and enzymes. These are the energy stations of the cell.

Plastids (peculiar to plant cells only!)

Their content in the cell main feature plant organism. There are three main types of plastids: leucoplasts, chromoplasts, and chloroplasts. They have different colors. Colorless leukoplasts are found in the cytoplasm of the cells of the unstained parts of plants: stems, roots, tubers. For example, there are many of them in potato tubers, in which starch grains accumulate. Chromoplasts are found in the cytoplasm of flowers, fruits, stems, and leaves. Chromoplasts provide the yellow, red, orange color of plants. Green chloroplasts are found in the cells of leaves, stems, and other plant parts, as well as in a variety of algae. Chloroplasts are 4-6 µm in size and often have an oval shape. In higher plants, one cell contains several dozen chloroplasts.

Green chloroplasts are able to transform into chromoplasts, which is why leaves turn yellow in autumn, and green tomatoes turn red when ripe. Leukoplasts can turn into chloroplasts (greening of potato tubers in the light). Thus, chloroplasts, chromoplasts and leukoplasts are capable of mutual transition.

The main function of chloroplasts is photosynthesis, i.e. in chloroplasts in the light, organic substances are synthesized from inorganic ones by converting solar energy into the energy of ATP molecules. Chloroplasts of higher plants are 5-10 microns in size and resemble a biconvex lens in shape. Each chloroplast is surrounded by a double membrane with selective permeability. Outside, there is a smooth membrane, and the inside has a folded structure. The main structural unit of the chloroplast is the thylakoid, a flat two-membrane sac that plays a leading role in the process of photosynthesis. The thylakoid membrane contains proteins similar to mitochondrial proteins that are involved in the electron transfer chain. The thylakoids are arranged in stacks resembling stacks of coins (from 10 to 150) and called grana. Grana has a complex structure: in the center is chlorophyll, surrounded by a layer of protein; then there is a layer of lipoids, again protein and chlorophyll.

Golgi complex

This is a system of cavities delimited from the cytoplasm by a membrane, which may have different shape. The accumulation of proteins, fats and carbohydrates in them. Implementation of the synthesis of fats and carbohydrates on membranes. Forms lysosomes.

Basic structural element Golgi apparatus - a membrane that forms packages of flattened tanks, large and small vesicles. The cisterns of the Golgi apparatus are connected to the channels of the endoplasmic reticulum. Proteins, polysaccharides, fats produced on the membranes of the endoplasmic reticulum are transferred to the Golgi apparatus, accumulated inside its structures and “packed” in the form of a substance ready either for release or for use in the cell itself during its life. Lysosomes are formed in the Golgi apparatus. In addition, it is involved in the growth of the cytoplasmic membrane, for example, during cell division.

Lysosomes

Bodies separated from the cytoplasm by a single membrane. The enzymes contained in them accelerate the reaction of splitting complex molecules into simple ones: proteins to amino acids, complex carbohydrates to simple, lipids to glycerol and fatty acids, and also destroy dead parts of the cell, whole cells. Lysosomes contain more than 30 types of enzymes (substances of a protein nature that increase the rate chemical reaction tens and hundreds of thousands of times), capable of breaking down proteins, nucleic acids, polysaccharides, fats and other substances. The breakdown of substances with the help of enzymes is called lysis, hence the name of the organoid. Lysosomes are formed either from the structures of the Golgi complex, or from the endoplasmic reticulum. One of the main functions of lysosomes is participation in intracellular digestion. nutrients. In addition, lysosomes can destroy the structures of the cell itself when it dies, during embryonic development, and in a number of other cases.

Vacuoles

They are cavities in the cytoplasm filled with cell sap, place of accumulation of spare nutrients, harmful substances; they regulate the water content in the cell.

Cell Center

It consists of two small bodies - centrioles and centrosphere - a compacted area of ​​​​the cytoplasm. Plays an important role in cell division

Organelles of cell movement

1. Flagella and cilia, which are cell outgrowths and have the same structure in animals and plants
2. Myofibrils - thin threads more than 1 cm long with a diameter of 1 micron, arranged in bundles along the muscle fiber
3. Pseudopodia (perform the function of movement; due to them, muscle contraction occurs)

Similarities between plant and animal cells

The features that plant and animal cells are similar to include the following:

1. A similar structure of the structure system, i.e. the presence of a nucleus and cytoplasm.
2. The exchange process of substances and energy is similar in principle of implementation.
3. Both in the animal and in plant cell has a membrane structure.
4. The chemical composition of cells is very similar.
5. In plant and animal cells, there is a similar process of cell division.
6. The plant cell and the animal have the same principle of transmitting the code of heredity.

Significant differences between plant and animal cells

Apart from common features structure and life of plant and animal cells, there are special distinctive features each of them.

Thus, we can say that plant and animal cells are similar to each other in the content of some important elements and some life processes, and also have significant differences in the structure and metabolic processes.