Comparative characteristics of plant and animal cells. Comparison of the structure of animal and plant cells. Key Similarities and Differences

Have cellular structure;

Irritability

6. growth is limited.

Subkingdom Multicellular

1. Two-layer radially symmetrical (sponges, coelenterates)

2. Three-layer bilaterally symmetrical (worms, mollusks, arthropods)

3. Three-layer radially symmetrical (echinoderms)

Main aromorphoses:

1. multicellularity

2. the appearance of symmetry (in the lower ones - radial; in the higher ones - bilateral)

3. cell specialization and differentiation

4. emergence of tissues

5. appearance of nerve cells and nervous system (not for everyone)

6. appearance of intracavitary digestion (partial or complete)

Sponge type(5 thousand species)

Origin is possible from colonial flagellates. They live in the seas and lead an attached lifestyle. There are both solitary and colonial forms. Freshwater sponge - freshwater sponge.

Main aromorphoses:

1. Multicellularity.

2. Differentiation of cells into a number of cell types

3. The appearance of germ cells specialized for reproduction.

Structure. The body shape resembles a glass or a bag. The whole body is riddled with pores. Through them, water with dissolved oxygen and food particles penetrate into the internal cavity. Water comes out through the outlet - the mouth. The outer layer of cells, the ectoderm, consists of flat surface cells (pinacocytes). The internal one - endoderm - is built of flagellar cells - choanocytes (they capture food, ensure the flow of water into the body). Amebocytes also take part in nutrition. Digestion is intracellular. Between the ecto- and endoderm there is mesoglea (jellylike substance), in which there are various cells: amoebocytes, stellate supporting cells (collencytes), skeletal cells (sclerocytes), undifferentiated cells - archaeocytes, mature and immature gametes, sometimes underdeveloped myocytes are present. Among pinacocytes, special cells stand out - porocytes, which have a through channel, close and open pores.

Reproduction asexual (budding or through the formation of special lumps of cells - gemmules) and sexual. Hermaphrodites or dioecious.

**During the process of ontogenesis, perversion (inversion) of the germ layers occurs, i.e. outer layer cells in larvae takes the position of the inner layer in adult sponges and vice versa.

Medical significance:

· bodyaga in medicinal purposes(bruise treatment)

· toilet sponges

· biological purification of natural waters - filters.

· glass sponges - souvenirs.

Type Coelenterates(9 thousand species)

Origin from multicellular flagellates (the first multicellular animals of the phagocytella type).

Classes: 1. Hydroid (able to move, but reluctant to do so)

2. Scyphoid = Jellyfish (mobile)

3. Coral polyps= Corals (sessile).

Main aromorphoses:

1. multicellularity;

2. formation of the first tissues: ectoderm and endoderm;

3. radial symmetry as a form of internal order;

4. differentiation of cells into a number of cell types;

5. the emergence of a nervous system consisting of individual cells connected by processes (reticular or diffuse NS);

6. appearance of partially intracavitary digestion.

general characteristics:

1) Two-layer (ectoderm and endoderm, gelatinous mesoglea between them).

2) Symmetry - radial.

3) The intestinal cavity ends blindly. They have partially cavity and intracellular digestion.

4) They have stinging cells (defense and hunting).

5) Soft-bodied, but may have an external or internal skeleton.

6) They reproduce sexually and asexually(budding, fragmentation). For some, the alternation of generations, the asexual generation of polyps, is replaced by the sexual generation - jellyfish.

7) Nervous system - diffuse type.

Meaning in nature and human life:
1) link in the food chain, regulate the number of fish, biological treatment sea ​​waters from suspended organic matter.
2) poisonous jellyfish(sea wasp, cross jellyfish)
3) scyphoid jellyfish can destroy fish, hydra eats fish fry.

4) symbiosis with some animals and plants, for example, sea anemones and hermit crabs, green hydra and chlorella algae.

5) some jellyfish (Aurelia, Rapilloma) are eaten by humans
6) coral polyps - a) reef formation; b) deposits of calcareous corals, an important link in the calcium and carbon dioxide cycle → formation of limestone (CaCO 3) → construction material; c) used for the manufacture of art and jewelry; d) some are poisonous.

Hydroid class(3 thousand species)

Solitary and colonial forms, mainly live in the seas.

Freshwater polyp hydra.. External structure: sole, stalk, body, tentacles (from 5 to 12); internal structure: mouth, intestinal cavity.

Ectoderm: 1) epithelial-muscle cells
2) glandular (secrete substances that promote attachment)
3) sensitive
4) stinging
5) nervous (in mesoglea)
6) intermediate (on the border)
7) sexual (formed from intermediate ones).

Endoderm: 1) epithelial-muscle cells
2) glandular
3) digestive.

Reproduction sexual and asexual (budding). They can be hermaphrodite or dioecious. Hydra lives for one summer and winters in the form of a zygote.

Movement: steps; on the tentacles; on the sole, due to the contraction of muscle fibers.

High ability to regenerate.

Class Scyphoid jellyfish (200 species)

Exclusively marine free-swimming animals. They are 98% water.

Structure. They look like a bell or an umbrella. Tentacles along the edge of the umbrella. On the lower concave side of the oral stalk with an oral opening, as a rule, it is framed by oral lobes. The intestinal cavity has radial canals that open into an annular canal lying along the edge of the umbrella.

They have sense organs: “eyes”, statocytes (they sense the approach of a storm), “olfactory fossa”.

Reproduction sexual and asexual. Life cycle with alternating sexual and asexual forms. Gametes are formed in the endoderm. Fertilization is often external. A larva emerges from the egg - a planula, first swims, then attaches to the substrate, and a polyp (scyphistoma) develops from it. Then it buds with transverse constrictions (“a stack of plates or disks”), young jellyfish (ethers) are separated.

Class Coral polyps (6 thousand species)

1) solitary - sea anemones (live from 15 to 66 years);

2) colonial - corals.

· There is no jellyfish stage in the life cycle.

· The intestinal cavity is divided by septa.

· They have a skeleton - horny or calcareous.

They reproduce by budding or sexually. Gametes are formed in the endoderm. From the fertilized eggs a planula emerges, which attaches and develops into a polyp. Colonies are formed by budding.

Type Flatworms(12 thousand species)

Main aromorphoses:

1) The emergence of a third germ layer― mesoderm, which gives rise to new organs and organ systems (excretory, muscular).

2) Bilateral symmetry - greater activity, the ability to swim and crawl.

3) The appearance of the anterior end of the body with a complex of sensory organs: vision, smell, touch.

4) The emergence of a nervous system (scalene type) consisting of lateral nerve trunks connected by jumpers; concentration of nerve cells at the anterior end of the body.

5) Education digestive system, including the anterior and middle sections, providing cavity digestion.

6) The appearance of an excretory system consisting of individual cells - protonephridia.

7) Formation of the reproductive system - permanent gonads.

General characteristics:

1. Flat, elongated, bilaterally symmetrical body.

3. Skin-muscle bag formed by three layers of muscles (in free-living animals).

4. There is no body cavity, the spaces between organs are filled with parenchyma.

6. Excretory system― individual cells of parenchyma and protonephridia ― system of tubules.

8. Nervous system - ladder type

Includes 9 classes, of which we will consider three.

Class Ciliated worms or Turbellaria (3.5 thousand species)

Planaria white. Size 0.5–1.5 cm. Has a skin-muscle bag (4 types of muscles). Movements: crawls and swims (planes, slightly bending the body). Sense organs: eyes (from 2 to several dozen) and tentacles. The digestive system has several parts: mouth → pharynx → branches of the intestine X no anus. Hermaphrodite. Reproduction: sexual (under bad conditions) and asexual (under favorable conditions - fragmentation, budding). Development is direct in freshwater, with metamorphosis in marine. They live in or near bodies of water in damp places.

Meaning:

1) predators

3) are included in the food chain.

Class Flukes or Trematodes (4 thousand species)

Life cycle of the liver fluke.

Medical significance:

1) Liver fluke causes the disease fascioliasis. May cause blockage of liver ducts and rupture of blood vessels. The disease is very difficult. Treatment is surgical.

3) Blood fluke - lives in the vessels of the abdominal cavity, causes schistomatosis, is common in tropical areas of Asia, Africa and South America. Cause tissue destruction in the kidneys and bladder. Eggs fall into the water with urine. Human infection occurs when swimming, when the larvae burrow into the skin and penetrate the blood, reach large veins and turn into adult worms.

Class Tapeworms or Cestodes (more than 3 thousand species)

Life cycle of the bovine tapeworm.

The main host is a person, the intermediate host is a large one cattle. Mature segments filled with eggs with the feces of a sick person end up on the soil, where cattle can swallow them along with the grass. In the intestines of the animal, microscopic larvae with hooks (oncospheres) emerge from the eggs. The larva then leaves the shell and penetrates the intestinal wall into the blood, spreads throughout the animal’s body and penetrates the muscles. Here it transforms into a larva new form- Finn - a pea-sized bottle, inside of which there is a tapeworm head with a neck. Human infection occurs by consuming meat (poorly cooked) containing fins. In the human intestine, under the influence of bile, the head turns out, attaches to the wall, and the growth of the worm’s body begins.

Medical significance:

1) Cestodes: bovine, pork tapeworm - cause diseases - cestodias. They cause human exhaustion, intoxication, and intestinal dysfunction. A person can be intermediate host pork tapeworm, and then Finns develop in his muscles. With their presence, Finns can cause serious illness.

Type Roundworms or Nematodes (20 thousand species)

They originated from free-living flatworms in the Proterozoic.

Main aromorphoses:

1) The appearance of a body cavity filled with fluid (serves as a hydroskeleton and is involved in metabolism).

2) Formation of the peripharyngeal nerve ring.

3) The appearance of the hindgut and anus (the digestion process has become continuous).

4) Dividing the muscle layer into longitudinal strands, increasing the efficiency of movement..

5) Dioeciousness (increasing the combinative diversity of the offspring).

General characteristics:

1) The body is elongated, non-segmented. Round in diameter.

2) The body is covered with a cuticle.

3) They have a body cavity filled with liquid.

4) The skin-muscle sac is formed by skin and 4 ribbons of longitudinal muscles.

5) The nervous system consists of a peripharyngeal ring and nerve trunks (abdominal and dorsal). The sense organs are poorly developed, usually the organs of touch around the mouth.

6) Digestive system: mouth → muscular pharynx → esophagus → intestines ending in the anus.

7) Excretory system - excretory canals and unicellular skin glands.

8) Dioecious. Reproduction is only sexual.

9) Constancy of the cellular composition of the body and lack of ability to regenerate.

Life cycle of the human roundworm.

Adult roundworms live in the small intestine of humans. The eggs, covered with a very dense shell (incredible viability), fall into the soil with feces. After 10 - 15 days, a larva develops inside the egg, and now a person can become infected. The egg with the larva inside passes through the mouth into the intestine, where a microscopically small larva emerges and penetrates the intestinal wall into the blood. The migration of larvae begins with the blood flow to the heart, then to the lungs. Here the larvae leave the bloodstream and penetrate the pulmonary vesicles, then rise through the bronchioles and bronchi into the trachea, reach (cough) the pharynx and are swallowed again. Now they enter the intestines, where adult worms grow.

Medical significance:

· release harmful, toxic substances; Patients experience fever, heart rhythm disturbances and other symptoms of poisoning.

· larvae entering the lungs cause hemoptysis and also open the way for bacteria to the internal organs.

Measures to prevent ascariasis: wash vegetables and fruits, hands before eating and after using the toilet, fight flies and cockroaches.

Meaning in nature:

1) Free-living - live in the soil (tens of millions of worms are found in 1 m 2 of soil). They are beneficial, mineralize plant and animal residues. For example, rotifers.

2) A link in the food chain of aquatic and soil communities.

Type Annelids or Annelids (9 thousand species)

Main aromorphoses:

1. The appearance of a secondary body cavity - the coelom, which has its own walls.

2. Dividing the body into segments.

3. Appearance of the cerebral ganglion, peripharyngeal nerve ring and ventral nerve cord.

4. The appearance of the circulatory system.

5. Appearance respiratory system(gills)

6. Complication of the digestive system, the appearance of sections, in particular the stomach.

7. Appearance of limbs - parapodia.

8. Formation of a multicellular excretory system.

Classification of insects

Two groups

1) Primary wingless - a very primitive group, a typical representative is the sugar silverfish (we don’t study it at school).

2) Winged. Among them, there are orders whose development occurs with complete (Coleoptera or beetles; Hymenoptera; Diptera; Lepidoptera or butterflies;) and incomplete (cockroaches, Orthoptera, lice, bedbugs) transformation. See table: "Orders of insects"

Ancestors of insects

Ancient arthropods similar in appearance to modern centipedes.

The importance of insects in nature and human life:

Type Echinoderms (6 thousand species)

Echinoderms are an independent and very peculiar type of animal. In terms of their structure, they are incomparable with any other animals and, thanks to the peculiarities of their organization and the original shape of their body, resembling a star, cucumber, flower or ball, they have long attracted attention. The name "echinoderms" was given by the ancient Greeks.

Ancestors

Echinoderms and chordates have the same ancestors. This is a group of ancient polychaete ringlets.

Classification of echinoderms

Five classes

Similarities and differences between animals and plants.

Similarities between plants and animals:

Consist of complex organic substances: proteins, fats and carbohydrates;

They have a cellular structure;

They have a similar nature of vital processes (metabolism and energy);

Growth by cell division and similar methods of reproduction;

Encoding, transmission and implementation hereditary information;

Irritability

This indicates the relationship of plants and animals, their origin from a common ancestor (divergent path of development of the organic world).

Differences between plants and animals.

General characteristics of animals:

1. nutrition with ready-made organic substances (heterotrophic);

2. lack of a dense outer membrane in the structure of cells;

3. in most cases, mobility and the presence of devices for movement

4. actively respond to environmental changes

5. most have various systems organs

6. growth is limited.

A cell is a single system that consists of elements that are naturally interconnected and has a complex structure. It is endowed with the ability for self-renewal, reproduction, and self-regulation.

What is a cell

All cells contain a cell membrane that surrounds its internal contents. It includes the nucleus, which performs the function of the brain and controls all processes occurring in it, and the cytoplasm, which occupies the entire space of the cell without the nucleus. This zone consists of a liquid called matrix or hyaloplasm and organelles (single and double membrane).

An organelle is a cell structure that performs specific functions. Without them, the cell will not be able to function normally.

The energy function is performed by mitochondria, which indicate the production of energy called ATP. The plant cell also contains two-membrane organelles - chloroplasts, the main function of which is photosynthesis. With their help, plants produce starch.

Another very large organelle plant cell- vacuole containing juice, reserve nutrients, which imparts color to plant components and can also act as a garbage collector.

The main organelles also include the endoplasmic reticulum - a system of channels that delimit all organelles, essentially its framework. There are two types of network - rough (granular) and smooth (agranular). On the rough surface there are ribosomes that perform the function of protein formation. Smooth - responsible for lipid synthesis.

Lysosomes are single-membrane organelles. With their help, substances entering the cell are broken down.

The common organelle for the two species is the Golgi complex, a system of closed vesicles and sacs. The main function is to form other single-membrane organelles. What plant and animal cells look like under a microscope, their features are clearly visible in the figure.

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General signs

Comparative characteristics show the similarities between plant and animal cells:

• They have the same structure general signs- This is the nucleus and cytoplasm.
• Unified chemical composition.
• Similarity of metabolic processes.
• Presence of a cell membrane.
• The division follows the same principle.

The main differences between plant and animal cells

First of all, plant and animal cells differ in shape. The first has a fixed rectangular shape, and the second has an irregular round shape.

The animal does not have a supramembrane complex (cell wall), which gives strength, chloroplasts and a large central vacuole. The core is located in the center, and not shifted to the wall, like in a plant one.

To illustrate the differences in cell structure, the table below is presented.

Conclusion and conclusions

By comparing the structure of plant and animal cells, we can conclude that they have a lot in common: structure, unity of the genetic code, chemical processes occurring inside and reproduction by division. The fundamental difference is in the method of nutrition: autotrophic and heterotrophic.

Are there any similarities between plants and animals at all? After all, these organisms are completely different from each other at first glance. In our article we will try to answer this question.

Similarities between plant and animal cells

Let's start with the cellular level of organization. Both plants and animals consist of precisely these structural units, which have the same chemical composition. Among these organisms there are unicellular and multicellular forms, as well as colonial ones.

They all have a common structure plan. The obligatory cellular structures are the surface apparatus, cytoplasm and permanent parts - organelles. Both plants and animals are eukaryotes. This means that their cells contain a nucleus. This structure contains nucleic acids in which all genetic information about organisms. All cells also contain inclusions. These are reserve nutrients that they use during unfavorable periods of life.

Signs of life

The similarities between plants and animals lie in the fact that they are representatives of living nature. This is very easy to prove. They eat, move, breathe, grow, develop, reproduce, metabolize, need water, and respond to stimuli.

But in the essence of these processes there are fundamental differences. For example, the way you eat. All plants are autotrophs. This means that they themselves are capable of synthesizing organic substances that they use to carry out life processes. Animals are not capable of this. They can only consume prepared food.

Classification issues

In some cases, the similarities between plants and animals are so obvious that scientists cannot decide on their systematic category. For example, Chlamydomonas has a light-sensitive eye and actively moves using flagella. These are typical signs of animals. But, according to the modern classification, Chlamydomonas (pictured above) is a representative of the Green algae department of the Plant kingdom based on autotrophic nutrition. Euglena has the same structure.

In some plants and animals the similarity is especially striking. These include sundew. This plant is a predator. Its leaves secrete a sticky, toxic substance containing digestive enzymes and a toxin that paralyzes the victim. When the insect sticks and remains immobilized, the edges of the leaf close and the trap slams shut. Within a few days, the victim's body is digested and absorbed by the plant.

Main differences

Plant and animal cells contain different organelles. The former are characterized by chloroplasts. These structures contain the green pigment chlorophyll and determine the process of photosynthesis. Their vacuoles are filled with cell sap, which is a solution of nutrients in water. Animal cells lack chlorophyll. Their vacuoles perform the function of regulating salt metabolism and food digestion.

The plant cell wall is strong and rigid. The carbohydrate cellulose gives it these properties. In animals it is soft and elastic. Beneath the cell membrane is a compacted layer of cytoplasm called the glycocalyx.

Plants and animals form different types fabrics. In the first, these are integumentary, basic, mechanical, conductive and educational. Animals have epithelial, muscle, connective and nervous tissue.

Despite the obvious similarities between plants and animals, there are fundamental differences between them. This is not only a way of eating, but also of movement. Animals do this actively, using the muscular system. Plants are characterized only by growth movements.

Animals' bodies increase in size only during a certain period of their life. This type of growth is called limited. Plant cells divide throughout their existence. This is unlimited growth.

So, in our article we looked at the similarities and differences between animals and plants. These organisms belong to different kingdoms of living nature. The same chemical composition and cellular structure indicate their common origin. They have similar characteristics: they grow and develop, reproduce and feed, breathe and carry out metabolism, and are capable of irritability. However, the mechanism of these processes in plants and animals has significant differences, which form the basis for their classification.

These structures, despite the unity of origin, have significant differences.

General plan of cell structure

When considering cells, it is necessary first of all to remember the basic patterns of their development and structure. They have common features structures, and consist of surface structures, cytoplasm and permanent structures - organelles. As a result of vital activity, organic substances called inclusions are deposited in them. New cells arise as a result of the division of maternal cells. During this process, two or more young structures can be formed from one original one, which are an exact genetic copy of the original ones. Cells, uniform in their structural features and functions, are combined into tissues. It is from these structures that the formation of organs and their systems occurs.

Comparison of plant and animal cells: table

On the table you can easily see all the similarities and differences in the cells of both categories.

Main differences

Comparison of plant and animal cell indicates a number of differences in the features of their structure, and therefore life processes. So, despite the unity of the general plan, their surface apparatus is different chemical composition. Cellulose, which is part of the cell wall of plants, gives them permanent form. Animal glycocalyx, on the contrary, is a thin elastic layer. However, the most important thing fundamental difference of these cells and the organisms they form lies in the way they feed. Plants have green plastids called chloroplasts in their cytoplasm. On their inner surface there is a complex chemical reaction converting water and carbon dioxide into monosaccharides. This process is only possible if there is sunlight and is called photosynthesis. The byproduct of the reaction is oxygen.

conclusions

So, we have compared plant and animal cells, their similarities and differences. The common features are the structure plan, chemical processes and composition, division and genetic code. At the same time, plant and animal cells are fundamentally different in the way they feed the organisms they form.

Similarities and differences between plants and animals

Between animals and plants, despite external differences, there are many similarities.

The similarity between plant and animal cells is found at the elementary chemical level. Modern methods chemical analysis found about 90 elements in living organisms periodic table. At the molecular level, the similarity is manifested in the fact that proteins, fats, carbohydrates, nucleic acids, vitamins, etc.

The peculiarity of the molecular organization of plant cells is that they contain the photosynthetic pigment - chlorophyll. Thanks to photosynthesis, oxygen accumulates in the Earth's atmosphere and hundreds of billions of tons of organic substances are formed annually.

Plants, like animals, 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 (n) set of chromosomes.

Cells of both plants and animals are surrounded by a thin cytoplasmic membrane. At the same time, 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. For this reason, plants feed osmotically. The intensity of nutrition depends on the size of the plant body surface in contact with environment. As a result, most plants experience significantly more high degree dismemberment than in animals, 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. It is in connection with this that the spread of animals and plants occurs in different periods ontogenesis: animals settle in the larval or adult state; plants develop new habitats by transporting dormant rudiments (spores, seeds) by 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. Glycogen accumulates in animal cells as reserve nutrients, and starch accumulates in plant cells.

The form of irritability in multicellular animals is a reflex, in plants - tropisms and nastia. In plants, both sexual and asexual reproduction occur, and in the vast majority of them there is an alternation of sexual and asexual generations. 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. Plant growth is almost continuous, and in most animals it is limited to a certain period of ontogenesis, after which growth stops. It is undeniable that modern plants and animals had common ancestors. It was they who served as the common root for the evolutionary development and divergence of plants and animals.

The reason for the similarity of plant and animal cells is the common origin of life.

The structure of plant and animal cells is common: 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 developmental paths, nutrition, the ability of animals to move independently, and the relative immobility of plants.

Plants have a cell wall (made of cellulose), but 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.

Question

Biomolecules are organic substances that are synthesized by living organisms. Biomolecules include proteins, polysaccharides, nucleic acids, as well as smaller metabolic components. Biomolecules consist of carbon, hydrogen, nitrogen, oxygen, as well as phosphorus and sulfur atoms. Other atoms are included in the composition of biologically significant substances much less frequently.

Similarities and differences between plants and animals - concept and types. Classification and features of the category “Similarities and differences of plants and animals” 2017, 2018.