Table of chemical elements cells examples and meanings. Chemical elements of the cell

Gametes are reproductive cells that have a haploid set of chromosomes and participate in gametic, in particular, sexual reproduction. When two gametes fuse during the sexual process, a zygote is formed, which develops into an individual with the hereditary characteristics of both parental organisms that produced the gametes.

In some species, the development of a single gamete into the body is possible - parthenogenesis.

Morphology of gametes and types of gametogamy

Isogamy, heterogamy and oogamy

The morphology of gametes of different species is quite diverse, while the produced gametes can differ in chromosome set, size and mobility, while gametic dimorphism in different species varies widely - from the absence of dimorphism in the form of isogamy to its extreme manifestation in the form of oogamy.

Isogamy

If merging gametes do not morphologically differ from each other in size, structure and chromosome composition, then they are called isogametes, or asexual gametes. Such gametes are motile, can bear flagella or be amoeboid. Isogamy is typical for many algae.

Anisogamy

Gametes capable of fusion vary in size; motile microgametes bear flagella; macrogametes can be either motile or immobile.

Oogamy

Sperm and egg.

Gametes of one biological species capable of fusion differ sharply in size and mobility into two types: small mobile male gametes - sperm - and large immobile female gametes - eggs. The difference in the size of gametes is due to the fact that the eggs contain a supply of nutrients sufficient to ensure the first few divisions of the zygote during its development into the embryo.

Male gametes - sperm - of animals and many plants are motile and usually carry one or more flagella, with the exception of male gametes of seed plants - sperm - lacking flagella, which are delivered to the egg during germination of the pollen tube, as well as flagellaless sperm of nematodes and arthropods.

Gametes are reproductive cells that have a haploid (single) set of chromosomes and participate in gametic, in particular, sexual reproduction. When two gametes fuse during the sexual process, a zygote is formed, which develops into an individual (or group of individuals) with the hereditary characteristics of both parental organisms that produced the gametes.

In some species, it is also possible for a single gamete (unfertilized egg) to develop into the body - parthenogenesis.

Morphology of gametes and types of gametogamy

Gametes are highly differentiated cells. In the process of evolution, they acquired adaptations to perform specific functions. The nuclei of both male and female gametes equally contain the hereditary information necessary for the development of the organism. But other functions of the egg and sperm are different, therefore they differ sharply in structure,

The eggs are immobile and have a spherical or slightly elongated shape. The egg contains all the typical cellular organelles, but its structure differs from other cells, since it is adapted to realize the possibility of developing a whole organism. The size of eggs is much larger than somatic ones. The intracellular structure of the cytoplasm in eggs is specific for each animal species, which ensures species-specific (and often individual) developmental characteristics. Eggs contain a number of substances necessary for the development of the embryo. These include the nutrient material (yolk). Some animal species accumulate so much yolk in their eggs that they can be visible to the naked eye. These are the eggs of fish and amphibians, the eggs of reptiles and birds. Of modern animals, the largest eggs are those of the herring shark - 29 cm in diameter; The diameter of an ostrich egg is 10.5 cm, a chicken egg is 3.5 cm. The eggs of animals in which the developing embryo receives nutrition from the environment, for example, higher mammals, are small in size. The diameter of a mouse egg is 60 centners, a cow egg is 100 centners. A human egg is 130-200 kg in diameter.

The morphology of gametes of different species is quite diverse, while the produced gametes can differ in chromosome set (if the species is heterogametic), size and mobility (ability to move independently), while gametic dimorphism in different species varies widely - from the absence of dimorphism in the form isogamy to its extreme manifestation in the form of oogamy.

Isogamy

Anisogamy (heterogamy)

Gametes capable of fusion vary in size, motile microgametes bear flagella, macrogametes can be either motile (many algae) or immobile (macrogametes of many protists lack flagella).

Oogamy

Sperm and egg. Gametes of one biological species capable of fusion differ sharply in size and mobility into two types: small male gametes and large immobile female gametes - eggs. The difference in the size of gametes is due to the fact that the eggs contain a supply of nutrients sufficient to ensure the first few divisions of the zygote during its development into the embryo.

Male gametes - sperm of animals and many plants are motile and usually carry one or more flagella, with the exception of male gametes of seed plants lacking flagella - sperm, which are delivered to the egg during germination of the pollen tube, as well as flagellaless sperm (sperm) of nematodes and arthropods.

Although sperm carry mitochondria, in oogamy only nuclear DNA is passed from the male gamete to the zygote; mitochondrial DNA (and in the case of plants, plastid DNA) is usually inherited by the zygote only from the egg.

More, others - less.

At the atomic level, there are no differences between the organic and inorganic world of living nature: living organisms consist of the same atoms as bodies of inanimate nature. However, the ratio of different chemical elements in living organisms and in the earth's crust varies greatly. In addition, living organisms may differ from their environment in isotopic composition chemical elements.

Conventionally, all elements of the cell can be divided into three groups.

Macronutrients

Zinc- is part of the enzymes involved in alcoholic fermentation, part of insulin

Copper- is part of the oxidative enzymes involved in the synthesis of cytochromes.

Selenium- participates in the regulatory processes of the body.

Ultramicroelements

Ultramicroelements make up less than 0.0000001% in the organisms of living beings, these include gold , silver have a bactericidal effect, inhibit the reabsorption of water in the renal tubules, affecting enzymes. Also referred to as ultramicroelements platinum And cesium. Some people also include selenium in this group; with its deficiency, cancer develops. The functions of ultramicroelements are still poorly understood.

Molecular composition of the cell

Macronutrients

Zinc- is part of the enzymes involved in alcoholic fermentation and insulin

Copper- is part of the oxidative enzymes involved in the synthesis of cytochromes.

Selenium- participates in the regulatory processes of the body.

Ultramicroelements

Ultramicroelements make up less than 0.0000001% in the organisms of living beings, these include gold, silver have a bactericidal effect, suppress the reabsorption of water in the renal tubules, affecting enzymes. Ultramicroelements also include platinum and cesium. Some people also include selenium in this group; with its deficiency, cancer develops. The functions of ultramicroelements are still poorly understood.

Table of chemical elements cells examples and meanings. Chemical elements of the cell

Morphology of gametes and types of gametogamy

Isogamy

Anisogamy

Oogamy

Macronutrients

Ultramicroelements

Molecular composition of the cell

see also

See what “Chemical composition of a cell” is in other dictionaries:

Macronutrients

Ultramicroelements

Molecular composition of the cell

see also

See what “Chemical composition of a cell” is in other dictionaries:

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