Similarities and differences between animal and plant cells. What are the similarities and differences between cells?

At the heart of diversity organic world lies the basic unit - the living cell. According to the current scientific concept, life began with nuclear-free prokaryotes, which, due to changes external conditions and improvements in internal processes evolved over time into eukaryotes. Such conclusions were drawn, including from the results of studying the cells of modern prokaryotes and eukaryotes. Scientists have established a significant similarity between these biological objects. The similarity between animal cells and bacteria lies in the fact that they have the same process of transmitting hereditary information, although the organelles (structural parts) have differences in both composition and functioning mechanisms.

Animals and plants are multicellular eukaryotic organisms. This means that all the tissues of their organisms consist of living eukaryotes. Despite the fact that all eukaryotes have prokaryotic symbionts, symbionts are not considered as part of their organisms, but have a separate classification.

Bacteria are unicellular organisms that consist of a single prokaryotic cell. There are many types of prokaryotic organisms that live in colonies, but colonies do not become multicellular creatures.

Animals reach truly enormous sizes, while the largest bacterium is not even visible to the naked eye. And yet, the main driving processes in these organisms have noticeable similarities.

The same structural elements of animal and bacterial cells:

• cell membrane;
• cytoplasm;
• ribosomes;
• DNA is the carrier of hereditary information;
• organelles for spatial movement (flagella, cilia, etc.).

These are the main details that make it possible to isolate the cellular space from the outside world, create an environment for metabolism in the cell and transmit hereditary information during reproduction.

In addition to these organelles, eukaryotic units of animals contain:

• nucleus (structure for storing DNA);
• desmosomes, which provide communication between eukaryotes, which makes it possible to form multicellular organisms;
• centrioles (needed for the division process);
• mitochondria (provide energy);
• lysosomes (break down organic matter).

There are a number of other organelles that synthesize complex proteins inside the cellular space, transport these proteins, and also maintain the cell in a tense state. Bacteria do not need these functions.

Most animal organelles (cellular units) arose as a result of the increased needs of a large eukaryote. In comparison, the prokaryotic monad is practically autonomous, and it does not need to create additional functionality to overcome additional difficulties associated with the overall complexity of the system.

Key Similarities

In addition to the differences, there are also significant similarities that confirm the relatedness of all living organisms, including animal cells and bacteria.

Cell membrane

This organelle is present in prokaryotic and eukaryotic biota (including plants and fungi). It determines the spatial configuration of the cell. It consists of proteins and lipids, thanks to which the transport of necessary substances and the transport of waste products is carried out. The cell membranes of nuclear and non-nuclear creatures may consist of proteins and lipids of different structures, but the principle of construction is always the same.

Cytoplasm

The internal environment of a living cell unit of bacteria, animals, plants and fungi. The similarity lies in the common features of the cytoplasm for all organisms - the combination of structural elements into one whole and aqueous composition. Water is the main component of the cytoplasm. Various mineral salts can be dissolved in water, organic compounds, glucose, but without water the cytoplasm is impossible.

Ribosome

An organelle found in the cells of bacteria, plants, animals and fungi that synthesizes proteins from amino acids using messenger RNA (mRNA) data. The mechanism of protein translation (synthesis) by ribosomes in eukaryotic units and in prokaryotic biota has similarities at almost all stages.

Carriers of hereditary information

In animals, plants and fungi in eukaryotic units, hereditary information is stored in DNA molecules, which are packaged in a nucleoprotein structure - a chromosome.

In prokaryotic biota, information about protein structures is also stored in DNA, but they do not need to be packaged into chromosomes. DNA is presented in the form of a circular macromolecule, which resides freely in the cytoplasm.

Moving and securing in space

Despite the fact that organelles of eukaryotic and prokaryotic structures have similarities in names (flagella, villi, cilia, etc.), they differ significantly in their structure. For example, a bacterial flagellum always rotates around its axis, while eukaryotic cells, if they have flagella, move the cell unit by bending along its entire length.

The general similarities between nuclear-free and nuclear organisms indicate the common nature of these living cells, but there are many differences between these two forms of organic life. Much more than similarities. Almost all vital processes occur differently in these cells.

A cell is the simplest structural element of any organism, characteristic of both animals and flora. What does it consist of? We will consider the similarities and differences between cells of plant and animal origin below.

plant cell

Everything that we have not seen or known before always arouses very strong interest. How often have you looked at cells under a microscope? Probably not everyone even saw him. The photo shows a plant cell. Its main parts are very clearly visible. So, a plant cell consists of a shell, pores, membranes, cytoplasm, vacuole, nuclear membrane, and plastids.

As you can see, the structure is not so tricky. Let us immediately pay attention to the similarities of plant and animal cells in terms of structure. Here we note the presence of a vacuole. In plant cells there is only one, but in animals there are many small ones that perform the function of intracellular digestion. We also note that there is a fundamental similarity in structure: shell, cytoplasm, nucleus. They also do not differ in membrane structure.

animal cell

In the last paragraph, we noted the similarities of plant and animal cells in terms of structure, but they are not absolutely identical, they have differences. For example, an animal cell does not also have the presence of organelles: mitochondria, Golgi apparatus, lysosomes, ribosomes, cell center. An essential element is the nucleus, which controls all cell functions, including reproduction. We also noted this when considering the similarities between plant and animal cells.

Cell Similarities

Despite the fact that the cells differ from each other in many ways, let us mention the main similarities. Now it is impossible to say exactly when and how life appeared on earth. But now many kingdoms of living organisms coexist peacefully. Despite the fact that everyone leads a different lifestyle and has a different structure, there are undoubtedly many similarities. This suggests that all life on earth has one common ancestor. Here are the main ones:

• cell structure;
• similarity of metabolic processes;
• information coding;
• same chemical composition;
• identical division process.

As can be seen from the above list, the similarities between plant and animal cells are numerous, despite such a variety of life forms.

Cell differences. Table

Despite a large number of similar features, cells of animal and plant origin have many differences. For clarity, here is a table:

The main difference is the way they eat. As can be seen from the table, a plant cell has an autotrophic method of nutrition, and an animal cell has a heterotrophic one. This is due to the fact that the plant cell contains chloroplasts, that is, the plants themselves synthesize all the substances necessary for survival, using light energy and photosynthesis. The heterotrophic method of nutrition refers to the ingestion of necessary substances into the body with food. These same substances are also a source of energy for the creature.

Note that there are exceptions, for example, green flagellates, which are able to obtain the necessary substances in two ways. Since the process of photosynthesis requires solar energy, they use the autotrophic method of nutrition during daylight hours. At night, they are forced to consume ready-made organic matter, that is, they feed heterotrophically.

To the question, what are the similarities and differences between cells? given by the author AlbinaSafronova the best answer is
A peculiarity of the molecular organization of plant cells is that they contain the photosynthetic pigment - chlorophyll.

Cells of both plants and animals are surrounded by a thin cytoplasmic membrane. However, plants still have a thick cellulose cell wall. Cells surrounded by a hard shell can absorb the substances they need from the environment only in a dissolved state. Therefore, plants feed osmotically. The intensity of nutrition depends on the size of the surface of the plant body in contact with environment. As a result, most plants exhibit a significantly high degree of dissection due to branching of shoots and roots.
The existence of hard cell membranes in plants determines another feature of plant organisms - their immobility, while in animals there are few forms that lead an attached lifestyle. That is why the distribution of animals and plants occurs in different periods of ontogenesis: animals disperse in the larval or adult state; plants develop new habitats by transporting rudiments (spores, seeds) that are at rest by the wind or animals.
Plant cells differ from animal cells in having special plastid organelles, as well as a developed network of vacuoles, which largely determine the osmotic properties of the cells. Animal cells are isolated from each other, but in plant cells, endoplasmic reticulum channels communicate with each other through pores in the cell wall. As spares nutrients Glycogen accumulates in animal cells, and starch accumulates in plant cells.
The form of irritability in multicellular animals is a reflex, in plants - tropisms and nasties. Plants have sexual and asexual reproduction. In animals, the determining form of reproduction of offspring is sexual reproduction.
Lower unicellular plants and unicellular protozoa are difficult to distinguish, not only in appearance. For example, green euglena, an organism that stands as if on the border of the plant and animal worlds, has a mixed diet: in the light it synthesizes organic substances with the help of chloroplasts, and in the dark it feeds heterotrophically, like an animal.

Answer from Ambassador[newbie]
The similarity between plant and animal cells is found at the elementary chemical level. Modern methods Chemical analysis revealed about 90 elements of the periodic table in the composition of living organisms. At the molecular level, the similarity is manifested in the fact that proteins, fats, carbohydrates, nucleic acids, vitamins, etc.
Plants have such living properties as growth (cell division due to mitosis), development, metabolism, irritability, movement, reproduction, and the germ cells of animals and plants are formed by meiosis and, unlike somatic ones, have a haploid set of chromosomes.
Cells of both plants and animals are surrounded by a thin cytoplasmic membrane.
Plant cells differ from animal cells in having special plastid organelles, as well as a developed network of vacuoles, which largely determine the osmotic properties of the cells. Animal cells are isolated from each other, but in plant cells, endoplasmic reticulum channels communicate with each other through pores in the cell wall.

As you know, living eukaryotic organisms are divided into three kingdoms: plants, fungi and animals. In this lesson we will learn the similarities and differences between eukaryotic cells. We will also answer the question: why are mushrooms allocated to a separate kingdom, although more recently they were classified as plants?

The similarity of eukaryotic cells is evidenced by a number of common characteristics:

1. General plan of the cell structure (presence of a cell membrane, cytoplasm and nucleus with organelles).

2. Fundamental similarity of metabolic and energy processes in the cell.

3. Encoding of hereditary information using nucleic acids.

4. Unity chemical composition cells.

5. Similar processes of cell division.

Figure 1 shows the table “Differences between plant and animal cells.”

Rice. 1. Difference between plant and animal cells

The main difference between the cells of the animal and plant kingdoms is their mode of nutrition. Plant cells are autotrophs, that is, they synthesize organic substances from inorganic ones using the energy of sunlight during the process of photosynthesis. Animal cells are heterotrophs, that is, the source of carbon for them is organic substances that come with food; these same substances also serve as a source of energy.

To ensure photosynthesis, plant cells contain plastids, for example chloroplasts, which contain the main pigment of photosynthesis - chlorophyll. There are no plastids in animal cells, but there are exceptions, for example plant flagellates, which include green euglena. In the dark, it feeds on ready-made organic substances (like an animal), and in the light it is capable of photosynthesis.

Since plant cells synthesize organic substances differently, their storage carbohydrates are also different. In plants, starch accumulates in cells, and in animals, glycogen is deposited.

A plant cell is characterized by the presence of a cell wall consisting of cellulose and pectin substances. The cell wall gives plant cells mechanical strength and support.

Most of the plant cell is occupied by a vacuole, which contains liquid. Vacuoles in a plant cell store organic substances, they contain hydrolytic enzymes (perform the function of lysosomes), they also participate in the regulation of cell pH and they isolate and neutralize toxic substances. An animal cell may contain small vacuoles that perform digestive and contractile functions. The structure of the vacuole in an animal cell differs from that of a plant cell.

In an animal cell, unlike a plant cell, there are centrioles.

Since a plant cell has a cell wall that protects its contents and provides a constant shape, it divides to form a septum. An animal cell divides with the formation of a constriction, since it does not have a cell wall.

Vacuoles are membrane-bound areas of a cell filled with fluid. The membrane that limits the vacuole from the cytoplasm is called tonoplast. It is a single membrane.

A young plant cell usually has many small vacuoles, which merge into one large one as the cell matures. In a mature plant cell, the vacuole can occupy up to 90% of its volume. Cell growth occurs due to the enlargement of the vacuole - this is the main role of the vacuole and tonoplast.

The main component of vacuolar sap is water; all other components vary greatly depending on the type of plant and its physiological state. Vacuoles may contain sugars, salts, and less commonly proteins; sometimes pigments are deposited in them.

The tonoplast plays an active role in the transport of certain ions into the vacuole.

The contents in the vacuole have a weakly acidic, acidic and, in rare cases, strongly acidic (lemon) reaction.

Vacuoles are a place where metabolic products accumulate. Sometimes they accumulate substances that are toxic to humans (nicotine alkaloid).

Vacuoles can serve as lysosomes because they contain hydrolytic enzymes that digest substances trapped inside the vacuole. When a cell dies, the contents of the vacuole pour out and begin to digest the cell (the process autolysis).

Fungal cells contain characteristics of plants and animals. They also have their own specific characteristics.

Signs of animal cells

Rice. 2. Symbiont mushrooms

Among the fungi there are predators that form sticky loops in the soil in which small nematode worms become entangled (see Fig. 3). Then the mycelium grows and penetrates the body of the worm, sucking out all the contents.

Rice. 3. Nematode worm in a sticky loop

Signs of a plant cell

WITH plant cell Fungal similarities are evident in the presence of a cell wall on top of the plasma membrane, but the fungal cell wall is primarily composed of chitin.

Just like plants, mushrooms are not capable of active movement, but are capable of unlimited growth.

Reproduction and distribution by spores also brings fungi closer to plants.

Special signs of mushrooms

The body of the fungus is formed by thread-like structures in one row of cells - hyphae. In some fungi, the partitions between the hyphae are lost and mycelium, consisting of one giant multinucleated cell. A collection of hyphae form mycelium.

Thus, the separation of fungi into a separate kingdom, numbering more than one hundred thousand species, is justified.

Some fungi play a key role in the mineral nutrition of vascular plants. Seedlings of many species of forest trees grown in a sterile nutrient solution and then transferred to meadow soil will grow poorly and even die from lack of food. However, if you add forest soil containing appropriate fungi to the soil, growth will normalize. This is due mycorrhiza(“mushroom root”), a close mutually beneficial symbiosis of roots and fungi.

Mycorrhizae are known in most groups of vascular plants. Only a few families of flowering plants do not form it or form it very rarely, for example, the Cruciferous and sedge families.

Many plants can develop normally without mycorrhiza if they are well supplied with essential elements, especially phosphorus. The participation of mycorrhiza in the direct transport of phosphorus from the soil to the roots has been proven experimentally. In turn, the plant supplies the symbiotic fungi with carbohydrates. One of the most amazing properties mycorrhizae - functioning under certain circumstances as a “bridge” for the transfer of photosynthetic products, phosphorus and, possibly, other compounds from one plant that forms it to another.

In the process of evolution, predatory fungi have developed various adaptations for capturing and digesting tiny animals, such as nematode roundworms.

Microscopic representatives of predatory fungi have been known for a long time, but recently it was found that some lamellar mushrooms, such as oyster mushrooms, are also predatory fungi. Oyster mushroom secretes a special substance that immobilizes nematodes, after which the mycelium entangles the worm and penetrates it. Enzymes are then produced that digest the worm's body. Subsequently, the mycelium sucks out the contents of the nematodes. Since oyster mushrooms live on rotten wood, which is poor in nitrogen, worms are a source of this element for this fungus.

Some microscopic fungi secrete a sticky substance on the surface of the hyphae, to which small animals (protozoa, small insects). Other fungi form loops that trap nematodes.

Bibliography

1. Kamensky A.A., Kriksunov E.A., Pasechnik V.V. General biology 10-11 grade Bustard, 2005.
2. Biology. Grade 10. General biology. Basic level / P.V. Izhevsky, O.A. Kornilova, T.E. Loshchilina and others - 2nd ed., revised. - Ventana-Graf, 2010. - 224 pp.
3. Belyaev D.K. Biology 10-11 grade. General biology. A basic level of. - 11th ed., stereotype. - M.: Education, 2012. - 304 p.
4. Agafonova I.B., Zakharova E.T., Sivoglazov V.I. Biology 10-11 grade. General biology. A basic level of. - 6th ed., add. - Bustard, 2010. - 384 p.

1. School.xvatit.com ().
2. Bio-faq.ru ().
3. Biouroki.ru ().

Homework

1. Questions at the end of paragraph 19 (p. 78) - Kamensky A.A., Kriksunov E.A., Pasechnik V.V. "General Biology", grades 10-11 ()
2. Evolutionarily, animal cells are capable of phagocytosis and pinocytosis. Due to what structural features of cells plants and fungi cannot do this?
3. It is known that plants eat through the process of photosynthesis. In this regard, they acquired additional organelles. Which? What is their function?

General in the structure of plant and animal cells: the cell is alive, grows, divides. metabolism takes place.

Both plant and animal cells have a nucleus, cytoplasm, endoplasmic reticulum, mitochondria, ribosomes, and Golgi apparatus.

Differences between plant and animal cells arose due to different paths of development, nutrition, the possibility of independent movement in animals and the relative immobility of plants.

Plants have a cell wall (made of cellulose)

animals do not. The cell wall gives plants additional rigidity and protects against water loss.

Plants have a vacuole, but animals do not.

Chloroplasts are found only in plants, in which organic substances are formed from inorganic substances with the absorption of energy. Animals consume ready-made organic substances that they receive from food.

Reserve polysaccharide: in plants – starch, in animals – glycogen.

Question 10 (How is the hereditary material organized in pro- and eukaryotes?):

a) localization (in a prokaryotic cell - in the cytoplasm, in a eukaryotic cell - the nucleus and semi-autonomous organelles: mitochondria and plastids), b) characteristics Genome in a prokaryotic cell: 1 ring-shaped chromosome - nucleoid, consisting of a DNA molecule (laying in the form of loops) and non-histone proteins, and fragments - plasmids - extrachromosomal genetic elements. The genome in a eukaryotic cell is chromosomes consisting of a DNA molecule and histone proteins.

Question 11 (What is a gene and what is its structure?):

Gene (from the Greek génos - genus, origin), an elementary unit of heredity, representing a segment of a deoxyribonucleic acid molecule - DNA (in some viruses - ribonucleic acid - RNA). Each protein determines the structure of one of the proteins of a living cell and thereby participates in the formation of a characteristic or property of the organism.

Question 12 (What is the genetic code, its properties?):

Genetic code- a method characteristic of all living organisms of encoding the amino acid sequence of proteins using a sequence of nucleotides.

Properties of the genetic code: 1. universality (the recording principle is the same for all living organisms) 2. triplet (three adjacent nucleotides are read) 3. specificity (1 triplet corresponds to ONLY ONE amino acid) 4. degeneracy (redundancy) (1 amino acid can be encoded by several triplets) 5. non-overlapping (reading occurs triplet by triplet without “gaps” and areas of overlap, i.e. 1 nucleotide cannot be part of two triplets).

Question 13 (Characteristics of the stages of protein biosynthesis in pro- and eukaryotes):

Protein biosynthesis in eukaryotes

Transcription, post-transcription, translation and post-translation. 1. Transcription consists of creating a “copy of one gene” - a pre-i-RNA molecule (pre-m-RNA). The hydrogen bonds between nitrogenous bases are broken and RNA polymerase is attached to the promoter gene, which “selects” nucleotides according to the principle of complementarity , and antiparallelism. Genes in eukaryotes contain regions containing information - exons and non-informative regions - exons. Transcription creates a “copy” of the gene, which contains both exons and introns. Therefore, the molecule synthesized as a result of transcription in eukaryotes is immature i-RNA (pre-i-RNA). 2. The post-transcription period is called processing, which involves the maturation of mRNA. What happens: Excision of introns and joining (splicing) of exons (splicing is called alternative splicing if exons are connected in a different sequence than they were originally in the DNA molecule). “Modification of the ends” of pre-i-RNA occurs: at the initial section - the leader (5"), a cap or cap is formed - for recognition and binding to the ribosome, at the end 3" - the trailer, polyA (many adenyl bases) is formed - for transport and - RNA from the nuclear membrane into the cytoplasm. This is mature mRNA.

3. Translation: -Initiation - binding of mRNA to the small subunit of the ribosome - entry of the starting triplet of mRNA - AUG into the aminoacyl center of the ribosome - union of two ribosomal subunits (large and small). -Elongation of the AUG enters the peptidyl center, and the second triplet enters the aminoacyl center, then two tRNAs with certain amino acids enter both centers of the ribosome. In the case of complementarity of triplets on i-RNA (codon) and t-RNA (anticodon, on the central loop of the t-RNA molecule), hydrogen bonds are formed between them and these t-RNAs with the corresponding AMCs are “fixed” in the ribosome. A peptide bond occurs between the AMCs attached to two tRNAs, and the bond between the first AMC and the first tRNA is broken. The ribosmoma takes a “step” along the mRNA (“moves one triplet”). Thus, the second t-RNA, to which two AMKs are already attached, moves to the peptidyl center, and the third triplet of mRNA ends up in the aminoacyl center, where from The next t-RNA with the corresponding AMK arrives in the cytoplasm. The process is repeated... until one of the three stop codons (UAA, UAG, UGA), which do not correspond to any amino acid, enters the aminoacyl center

Termination is the end of the assembly of a polypeptide chain. The result of translation is the formation of a polypeptide chain, i.e. primary protein structure. 4. Post-translation, the acquisition by a protein molecule of the appropriate conformation - secondary, tertiary, quaternary structures. Features of protein biosynthesis in prokaryotes: a) all stages of biosynthesis occur in the cytoplasm, b) the absence of exon-intron organization of genes, as a result of which a mature polycistronic m-RNA is formed as a result of transcription, c) transcription is coupled with translation, d) there is only 1 type of RNA polymerase (a single RNA- polymerase complex), while eukaryotes have 3 types of RNA polymerases that transcribe different types of RNA.