Most multicellular organisms inhabiting the earth are either plants or animals.It seems that the difference between them is so clear that you can not hesitate to define it at a glance.
How are the plants from animals
Any living organism belongs to any kind of, old, families, orders, and so on.Led by combining categories are the plant kingdom and the animal kingdom.Plants are able to create organic from inorganic materials in the process of photosynthesis and can not travel, animals eat plants and each other and actively move in search of food.
Carl Linnaeus, the founder of the classification of flora and fauna, plants defined as organisms that grow and live, and animals - grow, live and feel.This division does not meet the modern requirements of science.
qualities inherent in all living things
to stand out in the world of nature, living beings, it is necessary to determine which features are characteristic of all living organisms.First of all, all of the following characteristics:
1. Living organisms are capable of metabolism, metabolic products output and one way or another to obtain the necessary material for the continuation of life.
2. They can move or change the position of the body in space.
3. Their descendants are showing signs of parental organisms.
4. Individuals of one species differ from each other, and the differences may be dependent and not dependent on heredity.
5. Organisms selectively react to stimuli.
6. Most of the living creatures has the ability to grow and grow.
7. During the life of organisms undergo irreversible changes.
8. They can reproduce themselves like organisms.
What are the characteristics of a living ubiquitous
Many features of living organisms, if taken separately, may be inherent in the world of inanimate nature.For example, have the ability to grow crystals, stones very slowly, but break down, they may eventually move from its original location.Air, water, planets and even galaxies are moving.Conversely, the seeds for a long time can not show his qualities and not different from the grains of sand.
important link between the world of the living and inanimate nature, is a virus that is not capable of metabolism, can be prepared in the form of crystals, dissolved and recrystallized, and they did not lose after all this inherent biological properties.Signs of living organisms - is primarily the more complicated chemical composition and the presence of certain biological molecules in their structure.Special molecules of living organisms are proteins and nucleic acids.
Plants-deceivers
in nature are very unusual plants with atypical features, which makes it necessary to determine which features are characteristic of animals, and which - for the plant.There are plants that are indistinguishable from the stones.They are similar to limestone, granite and white quartz.These plants are called Lithops.As inhabitants of the desert, they rarely get water and can exist by absorbing moisture from the fog.
known that plants are able to react to the irritation and secrete chemicals that transmit their feeling that the plants produce plant hormones.
There are many plants that can not carry out photosynthesis, and receive nutrients, enticing and digesting insects and small animals.Among them - the sundew, Venus flytrap, which kept the leaves and stems that are typical for plants, but with other functions.
There are also carnivorous plants Rafflesia Arnoldi, whose flower was only a reddish-brown color.The plant does not carry out photosynthesis, it has no parts specific to the plant, only the structure of the cells allowed to take it to the realm of living things, not a predatory animal.
How to distinguish plants from animals
In order to determine the identity of some organisms to a particular group of living beings, science should have an unequivocal answer to the question "What are the signs typical for animals, what distinguishes them from the plants."However, give a definite answer about the difference between the representatives of the kingdom of plants and animals by their appearance is difficult.
modern taxonomy is forced to carry out complex research involving opportunities related sciences.For this purpose, methods of analysis of genetic and molecular characteristics of the species, as well as details of their embryonic development.
Animals are not like animals
to determine the identity of some of the sea creatures in the animal kingdom, it was required to specify what attributes of a living organism are characteristic of animals.It took scientists more than a year, to organisms in which the digestive system is absent, who lived attached to the substrate, and were similar to the unusual flowers, were referred to as animal.Therefore, to correctly determine what species of living beings is the unknown organism, it is necessary to determine which features are characteristic of animals.
Determine the group of marine invertebrates belonging to a particular type of known organisms it was so difficult that initially it was decided to put them in the realm of Pogonophora.These organisms as an adult deprived of the digestive system, and apparently they are nothing like the animals.Only a study of the characteristics of their embryonic development has allowed to carry them to annelids.
features characteristic only for the animal kingdom
in the animal kingdom are many organisms that are adapted to all kinds of environmental conditions.It altered the structure and their appearance.To understand what challenges faced by zoologists, is a modern taxonomy of living organisms, list the characteristics of an animal.So, the majority of animals:
1. There is no photosynthesis, these organisms are heterotrophic.
2. Food enters through the mouth into the digestive cavity and digested in the specialized agencies.Power is active.
3. Animals organisms are able to move.When they live on some substrate, the existence of this method is a secondary phenomenon.
4. The response to the external stimulus is in the form of taxis in the absence of the nervous system, or if any reflex.
to clearly answer what symptoms are characteristic of animals, you need to decide what type of organism in question is a single-celled or multicellular, chordates or vertebrates.Only the higher animals can talk about such features, like:
1. The presence of several groups of fabrics: integumentary, muscle, nerve tissue and internal environment.
2. The presence of the following systems: musculoskeletal, digestive, respiratory, excretory, reproductive, circulatory and nervous.
plants What is the difference from the animals at the microscopic level
to give a definitive answer to the question of the difference between the representatives of the two largest kingdoms, it is necessary to determine which features are characteristic of animals, what distinguishes them from plants at the cellular level.
main features that distinguish the plant cell:
1. In plant cells, in addition to the membrane, there is a very solid cell wall composed of cellulose.
2. Spare carbohydrates in plants deposited in the form of the polysaccharide starch.
3. The cells have large vacuoles containing cell sap.
4. The cytoplasm has inclusions in the form of mineral salt crystals.
5. Green plant cells contain plastids - chloroplasts, where photosynthesis takes place.
6. Digestive absent and the food comes in by osmosis plant.
7. The response to external stimulation in the form of tropism.
8. There is no capacity for motion.
9. When cell division constriction formed between them in the center and spread to the periphery.
It is also necessary to determine which features are characteristic of the animals at the cellular level.
1. cell wall is missing, there is the cell membrane, which is present in plant cells.
2. the Reserve polysaccharide is glycogen.
3. In animal cells there are no large vacuoles.In the simplest organisms have small vacuoles, which serve as the digestive or selection.
4. The inorganic salts in animal cells, usually dissolved.
5. In animal cells there is no photosynthesis and chloroplasts.
6. Shifting during cell division is formed from the edges and spreads to the center of the cell.
