Gametangia that produce men's gametes are called antheridia, and gametangia, producing female gametes are archegonia. Fertilization of female gametes (ovules) in land plants, as a rule, occurs in archegonium, after which a diploid sporophyte develops from a fertilized egg, or zygote, which at first depends on the gametophyte. In most multicellular algae, fertilization occurs in water (isogamy, heterogamy and oogamy) and the sporophyte formed as a result of fertilization does not depend on the gametophyte. IN different groups higher plants and algae, the gametophyte is developed to varying degrees. In some, it exists for a short time (ferns), in others it prevails throughout life (mosses).

Variety of gametophytes in algae

In many algae, the correct alternation of gametophyte and sporophyte generations is observed, although in some algae there are two diploid generations per haploid generation (for example, in red algae Polysiphonia dioecious filamentous gametophytes are replaced by a generation of carposporophyte, which forms diploid carpospores, and then a generation of tetrasporophyte, which forms haploid tetraspores). At the red algae Palmaria large lamellar male gametophytes are morphologically similar to sporophytes, and female gametophytes are microscopic (0.1 mm in diameter). In bangui red algae, the macrothallomic form is the gametophyte. The sporophyte is represented by microscopic filamentous thalli that drill into the shells of molluscs. Brown kelp algae have huge lamellar sporophytes and microscopic filamentous dioecious gametophytes. In the green alga ulva, from the order ulvae, the gametophytes have a large lamellar thallus, morphologically indistinguishable from the sporophyte thallus (with the exception of the reproductive organs); since the ulvae are isogamous, their gametophytes are not called male and female, but +=gametophyte and --gametophyte.

Variety of gametophytes of higher plants

In higher plants, there is always a regular alternation of two multicellular generations - the sporophyte and the gametophyte. In flowering plants, the male gametophytes are so small that they fit inside the shell of a pollen grain) and consist of only a few cells. The female gametophyte of flowering plants (embryo sac) is placed inside the ovule and consists of 7 cells (or contains 7 nuclei). In ferns, horsetails and club mosses, the gametophyte is a small but independent plant, sometimes called outgrowth. Plants of ferns and horsetails are photosynthetic, annual. Club moss growths live underground, develop over many years and feed on symbiosis with fungi. In mosses, the gametophyte, despite its small size, clearly dominates the sporophyte. Gametes in higher plants are always formed as a result of mitosis (which fundamentally distinguishes them from animal gametes), since the body of the gametophyte is also built from haploid cells. Therefore, the gametophyte phase is also called the gametophase, or haplophase. It should be noted that both male and female genital organs can develop simultaneously on one gametophyte. Such a gametophyte is called monoecious (bisexual). In other cases, the gametophytes of plants belonging to the same species form either only male organs or only female ones. Such gametophytes are called dioecious (separate - male and female). Dioecious gametophytes are characteristic of all seed plants, in which male gametophytes develop from microspores formed in anthers, and female - from megaspores formed in ovules.

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See what "Gametophyte" is in other dictionaries:

Gametophyte ... Spelling Dictionary

- (from gamete and Greek phyton plant) sexual generation, stage of the life cycle of plants; alternates with sporophyte. It is formed from a spore, contains a haploid set of chromosomes; produces gametes in gametangia. In angiosperms, gametophytes are reduced ... ... Big encyclopedic Dictionary

- (from gamete and ... fit), sexual generation in life cycle plants that develop with alternation of generations. It is formed from a spore, has a haploid set of chromosomes; produces gametes either in ordinary vegetative cells of the thallus (some algae), ... ... Biological encyclopedic dictionary

Exist., number of synonyms: 2nd generation (6) prothallium (2) ASIS synonym dictionary. V.N. Trishin. 2013 ... Synonym dictionary

See sporophyte. Geological dictionary: in 2 volumes. M.: Nedra. Edited by K. N. Paffengolts et al. 1978 ... Geological Encyclopedia

gametophyte- Haploid, gamete-forming generation in the life cycle of plants, characterized by alternation of generations; gametes are produced in specialized gametangia or in any part of the thallus (in some algae); in the evolution of plants ... ... Technical Translator's Handbook

- (from gamete and Greek phytón plant), sexual generation, stage of the life cycle of plants; alternates with sporophyte. It is formed from a spore, contains a haploid set of chromosomes; produces gametes in gametangia. In angiosperms, the gametophyte is reduced ... ... encyclopedic Dictionary

- (see gametes + ... fit) the sexual generation in plants, alternating with the asexual (sporophyte), in many plants r. leads an independent existence and does not differ in appearance from asexual generation (e.g. in many algae) or vice versa... Dictionary foreign words Russian language

Gametophyte gametophyte. Haploid, gamete-forming generation in the life cycle of plants characterized by alternation of generations ; gametes are produced in specialized gametangia or in any site ... ... Molecular biology and genetics. Dictionary.

gametophyte- PLANT EMBRYOLOGY GAMETOPHYT, HAPLOPHYT, HAPLOID GENERATION, GENERATIVE GENERATION - the sexual generation in flowering plants, which has a haploid (n) number of chromosomes ... General Embryology: Terminological Dictionary

1. Gametophyte

GAMETOFIT- sexual generation in the life cycle of plants developing with alternation of generations. It is formed from a spore, has a haploid set of chromosomes; produces gametes either in ordinary vegetative cells of the thallus (some algae) or in specialized organs of sexual reproduction - gametangia, oogonia and antheridia (lower plants), archegonia and antheridia (higher plants with the exception of flowering plants).

gametophyte-haploid multicellular phase in life cycle plants And algae, developing from dispute and producing sex cells, or gametes.

Develops from haploid dispute. On the gametophyte in special organs gametangia sex cells develop gametes. Gametangia that produce men's gametes are called antheridia, and the gametangia producing female gametes - archegonia. Fertilization of female gametes (ovules) in land plants usually occurs in the archegonium, after which from the fertilized egg, or zygotes develops diploid sporophyte, which at first depends on the gametophyte. In most multicellular algae, fertilization occurs in water (isogamy, heterogamy and oogamy) and the sporophyte formed as a result of fertilization does not depend on the gametophyte. In different groups of higher plants and algae, the gametophyte is developed to varying degrees. In some, it exists for a short time (ferns), in others it prevails throughout life (mosses).

At mosses the gametophyte, with its small size, clearly dominates sporophyte. Gametes in higher plants are always formed as a result of mitosis(which fundamentally distinguishes them from animal gametes), since the body of the gametophyte is also built from haploid cells. Therefore, the gametophyte phase is also called the gametophase, or haplophase. It should be noted that both male and female genital organs can develop simultaneously on one gametophyte. Such a gametophyte is called monoecious (bisexual). In other cases, the gametophytes of plants belonging to the same species form either only male organs or only female ones. Such gametophytes are called dioecious (separate - male and female). Dioecious gametophytes are characteristic of all seed plants in which male gametophytes develop from microspores formed in anthers, and female - from megaspores formed in ovules.

2. Sporophyte

sporophyte- diploid multicellular phase in the life cycle of plants and algae, developing from a fertilized egg or zygote and producing spores.

It develops from a fertilized egg, or zygote. On the sporophyte in special organs - sporangia - as a result of meiosis, haploid spores develop.

In different groups of plants and algae, it is developed to varying degrees. At flowering plants, gymnosperms and vascular spores ( club mosses, horsetail And ferns) the sporophyte is much larger than the gametophyte. Actually, everything that we usually call a plant is its sporophyte. Gametophytes of seed plants spend most of their lives in the spore shell (microspores are pollen, and macrospores are in ovules), and in vascular spore gametophyte - a small but independent multicellular plant. At mosses on the contrary, the gametophyte dominates the life cycle. The sporophyte quickly dries out and consists only of a stem and a cap-sporangium with spores.

Plant generative organs: archegonium (top) and antheridium (bottom)

The basis of sexual reproduction (or reproduction) is the sexual process - the fusion of male and female gametes. The organs that form them - antheridia and archegonia - develop on plants of the sexual generation - gametophytes. In higher plants, they are always multicellular, like sporangia.

The internal fertile cells of the antheridium constitute the spermatogenic tissue that forms the male gametes (spermatozoa). A typical mature archegonium consists of an expanded abdomen and a narrow neck filled with cervical tubular cells. In the process of evolution, the number of fertile cells was reduced to a single egg. Fertilization is internal, in the abdomen of the archegonium. The resulting zygote is the first cell of the sporophyte.

There are 3 sexual processes: 1. isogamy - fusion of 2 identical gametes; 2. heterogamy-fusion of 2 gametes of different size, but they do not differ in mobility; 3. oogamy-fusion of 2 specialized gametes (ovum and spermatozoon)

gametophyte - haploid multicellular phase in the life cycle of plants and algae, developing from spores and producing sex cells, or gametes.

In higher plants, there is always a regular alternation of two multicellular generations - the sporophyte and the gametophyte. In flowering plants, the male gametophytes are so small that they fit inside the shell of a pollen grain and consist of only a few cells. The female gametophyte of flowering plants (embryo sac) is placed inside the ovule and consists of 7 cells (or contains 7 nuclei). In ferns, horsetails and club mosses, the gametophyte is a small but independent plant, sometimes called an outgrowth. Plants of ferns and horsetails are photosynthetic, annual. Club moss growths live underground, develop over many years and feed on symbiosis with fungi. In mosses, the gametophyte, despite its small size, clearly dominates over the sporophyte. Gametes in higher plants are always formed as a result of mitosis (which fundamentally distinguishes them from animal gametes), since the body of the gametophyte is also built from haploid cells. Therefore, the gametophyte phase is also called the gametophase, or haplophase. It should be noted that both male and female genital organs can develop simultaneously on one gametophyte. Such a gametophyte is called monoecious (bisexual). In other cases, the gametophytes of plants belonging to the same species form either only male organs or only female ones. Such gametophytes are called dioecious (separate - male and female). Dioecious gametophytes are characteristic of all seed plants, in which male gametophytes develop from microspores formed in the anthers, and female - from megaspores formed in the ovules.

sporophyte - diploid multicellular phase in the life cycle of plants and algae, developing from a fertilized egg or zygote and producing spores.

It develops from a fertilized egg, or zygote. On the sporophyte in special organs - sporangia - as a result of meiosis, haploid spores develop. In many plants (heterosporous club mosses and heterosporous ferns, as well as gymnosperms and flowering plants), sporangia are divided into two types: macro- and microsporangia. Macrosporangia produce macrospores and microsporangia produce microspores. Female gametophytes develop from macrospores, and male gametophytes develop from microspores. In flowering plants, gymnosperms and vascular spores (mosses, horsetails and ferns), the sporophyte is much larger than the gametophyte. Actually, everything that we usually call a plant is its sporophyte.

In the development cycle of mosses, the gametophyte, the sexual generation (the plant itself), predominates, while the sporophyte, the asexual generation, is reduced and is represented by a sporogon in the form of a box on a leg. The development of bryophytes went in the direction of increasing the independence of the gametophyte and its gradual morphological division, the loss of independence of the sporophyte and its morphological taming. The gametophyte became an independent, completely autotrophic phase of the life cycle of bryophytes, while the sporophyte was reduced to the level of an organ of the gametophyte.

Mosses, as representatives of the haploid branch of the evolution of higher plants, turned out to be less viable and adapted to the conditions of life on Earth. Their distribution is associated with the presence of free drop-liquid water, which is necessary not only for growth processes, but also for the sexual process. This explains their ecological confinement to places where there is constant or periodic moisture.

The second evolutionary branch of higher plants is represented by all other higher plants.

Two lines of evolution. The evolution of the gametophyte and sporophyte went in 2 directions: the evolution of the sporophyte is directed towards dominance. The evolution of the sexual generation has gone in the direction of reduction, the reduction leads to the protection of the sexual generation.

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The meaning of the word gametophyte

gametophyte in the crossword dictionary

Encyclopedic Dictionary, 1998

gametophyte

GAMETOPHYT (from gamete and Greek phyton - plant) sexual generation, stage of the life cycle of plants; alternates with sporophyte. It is formed from a spore, contains a haploid set of chromosomes; produces gametes in gametangia. In angiosperms, it is reduced to a speck of dust (male gametophyte) and an embryo sac (female gametophyte).

gametophyte

It develops from haploid spores. On the gametophyte in special organs gametangia, germ cells develop

gametophyte gametophyte

(from gamete and ... fit), sexual generation in the life cycle of plants developing with alternation of generations. It is formed from a spore, has a haploid set of chromosomes; produces gametes either in ordinary vegetative cells of the thallus (some algae), or in specialized. organs of sexual reproduction - hemetangia, oogonia and antheridia (lower plants), archegonia and antheridia (higher plants with the exception of flowering). G.'s structure is diverse, which is associated with decomp. types of generational change. With an isomorphic change of generations in algae (ulva, dictyota, ectocarpus), G. is represented by an independently living individual of this species, outwardly not differing from a diploid individual - a sporophyte. With a heteromorphic life cycle (kelp algae), G. looks microscopic. filamentous, weakly branching thalli and differs sharply from a large sporophyte. In higher plants, which always have a heteromorphic alternation of generations, only in mosses can G. be represented by a leaf-stem plant (sphagnum, cuckoo flax). In all other representatives of the sporophyte line of evolution (fern-like, seed plants), the G. is poorly developed and short-lived. So, in club mosses, horsetails and ferns, G. have the appearance of thallus plants - growths that are not divided into organs, green or colorless, from several. mm to 3 cm, living several. weeks (rarely several years, as in club mosses and maratti ferns). In isosporous ferns, the growths are bisexual. Heterosporous higher plants, including seed plants, have dioecious G., developing from micro- and macrospores. In the evolution of higher plants, a gradual reduction of G. So, wives. the sexual generation of seed plants has completely lost the ability to live independently, and all its development takes place on the sporophyte inside the macrosporangium (or nucellus of the ovule). In gymnosperms. G. - multicellular haploid endosperm with two (in pine) or several. (in other gymnosperms) archegonia. Female G. angiosperms is usually reduced to seven cells, has no archegonium and is called. embryo sac. Husband. D, seed plants develop from microspores and are pollen germinating into the pollen tube with the formation of gametes - sperm.

.(Source: "Biological Encyclopedic Dictionary." Chief editor M. S. Gilyarov; Editorial board: A. A. Babaev, G. G. Vinberg, G. A. Zavarzin and others - 2nd ed., corrected . - M .: Sov. Encyclopedia, 1986.)

See what "Gametophyte" is in other dictionaries:

Gametophyte ... Spelling Dictionary

Gametophyte The haploid multicellular phase in the life cycle of plants and algae that develops from spores and produces sex cells, or gametes. It develops from haploid spores. On the gametophyte in special organs, gametangia develop ... ... Wikipedia

- (from gamete and Greek phyton plant) sexual generation, stage of the life cycle of plants; alternates with sporophyte. It is formed from a spore, contains a haploid set of chromosomes; produces gametes in gametangia. In angiosperms, gametophytes are reduced ... ... Big Encyclopedic Dictionary

Exist., number of synonyms: 2nd generation (6) prothallium (2) ASIS synonym dictionary. V.N. Trishin. 2013 ... Synonym dictionary

See sporophyte. Geological dictionary: in 2 volumes. M.: Nedra. Edited by K. N. Paffengolts et al. 1978 ... Geological Encyclopedia

gametophyte- Haploid, gamete-forming generation in the life cycle of plants, characterized by alternation of generations; gametes are produced in specialized gametangia or in any part of the thallus (in some algae); in the evolution of plants ... ... Technical Translator's Handbook

- (from gamete and Greek phytón plant), sexual generation, stage of the life cycle of plants; alternates with sporophyte. It is formed from a spore, contains a haploid set of chromosomes; produces gametes in gametangia. In angiosperms, the gametophyte is reduced ... ... encyclopedic Dictionary

- (see gametes + ... phyt) the sexual generation in plants, alternating with the asexual (sporophyte), in many plants the r. leads an independent existence and does not differ in appearance from the asexual generation (for example, in many algae) or, vice versa … Dictionary of foreign words of the Russian language

Gametophyte gametophyte. Haploid, gamete-forming generation in the life cycle of plants characterized by alternation of generations ; gametes are produced in specialized gametangia or in any site ... ... Molecular biology and genetics. Dictionary.

gametophyte- PLANT EMBRYOLOGY GAMETOPHYT, HAPLOPHYT, HAPLOID GENERATION, GENERATIVE GENERATION - the sexual generation in flowering plants, which has a haploid (n) number of chromosomes ... General Embryology: Terminological Dictionary