Life cycle of gymnosperms class 11? (2023)

What is the life cycle of gymnosperms Class 11?

The life cycle of gymnosperms is both haploid and diploid, i.e., they reproduce through the alternation of generations. They have a sporophyte-dominant cycle. The gametophyte phase is relatively short. The reproductive organs are usually cones.

The gymnosperm life cycle has a dominant sporophyte generation. Pollination occurs when pollen is transferred from a male to female cone. Zygotes develop into embryos inside seeds, from which the next generation grows. If the seed germinates, it may grow into a mature sporophytes tree, which repeats the cycle.

Gymnosperms are vascular plants that produce seeds in cones. Examples include coniferssuch as pine and spruce trees. The gymnosperm life cycle has a dominant sporophyte generation. Both gametophytes and the next generation's new sporophytes develop on the sporophyte parent plant.

The gametophytic phase is represented by the single to few called haploid gametophytes which are short-lived and is dependent on the photosynthetic sporophyte. This pattern of the life cycle is present in gymnosperms. Was this answer helpful?

Gymnosperm plants have naked seeds, which means that their seeds are not covered within a fruit. The plant body consists of intermediate to tall shrubs and trees. The gigantic redwood tree that is Sequoia is among the world's tallest trees.

In gymnosperms, when the nuclei of the two sperm meet the egg cell, one nucleus dies and the other unites with the egg nucleus to form a diploid zygote. The fertilized egg undergoes mitosis to begin the development of a new sporophyte generation—the multicellular embryo of the seed.

The main stages in the life cycle of a plant are seed germination, seedling formation, growth, development and differentiation leading to a mature plant, pollination and fertilisation and the formation of fruit and seeds.

The gymnosperm life cycle typically takes two years to complete. The cycle begins as male cones release pollen grains. Pollen grains are carried by the wind and reach female cones.

Plantlife cycles consist of five stages: seed, seed germination, seedling, adult plant, and pollination and fertilization.

Gymnosperms possess several key evolutionary innovations compared to earlier groups such as the clubmosses and ferns. They produce sperm-containing pollen, which is carried through the air by the wind to the female. This innovation has freed these plants from the need for water for sexual reproduction.

How are the life cycles of angiosperms and gymnosperms different?

Though they both have sporophyte-dominated life cycles, angiosperms and gymnosperms differ in that angiosperms have flowers, fruit-covered seeds, and double fertilization, while gymnosperms do not have flowers, have “naked” seeds, and do not have double fertilization (more on this later).

The life cycle of a gymnosperm includes both diploid sporophyte and haploid gametophyte. The haploid phase comprises the male and female gametophyte, and is restricted to few cells. They remain confined to the microsporangium and megasporangium present on the sporophylls. They give rise to the sperm and egg cells.

Gymnos - naked, and sperma - seeds, i.e seeds are not produced inside the fruits. Gymnosperms means plants with naked seeds. They are mainly perennial or woody. Their stem can be branched or unbranched.

The present living Gymnosperms are Cycadales, Ginkgoales, Coniferales and Gnetales. But Ginkgoales is the only order with a single genera, that is Ginkgo biloba, a "living fossil" with no close relatives (more diverse in the Jurassic).

Gymnosperms consist of four main phyla: the Coniferophyta, Cycadophyta, Gingkophyta and Gnetophyta. Conifers are the dominant plant of the gymnosperms, having needle-like leaves and living in areas where the weather is cold and dry.

Gymnosperm Reproduction

Some gymnosperm species have male and female cones on the same tree, while others have separate male or female cone producing trees. In order for pollination to take place, gametes must come into contact with one another. This typically occurs via wind, animal, or insect transfer.

The reproductive structures in gymnosperms are called cones or strobili. The strobili bearing microsporophylls and microsporangia are called microsporangiate or male strobili. The cones bearing megasporophylls with ovules or megasporangia are called macrosporangiate or female strobili.

In gymnosperms, a leafy green sporophyte generates cones containing male and female gametophytes; female cones are bigger than male cones and are located higher up in the tree. A male cone contains microsporophylls where male gametophytes ( pollen ) are produced and are later carried by wind to female gametophytes.

Gymnosperms do not have any flowers and seeds on the surface of scales and leaves. Strobilus is known as the structure of the gymnosperms. Both males and females can be considered under Pinus and Cycas. It contains two types of tissues known as the xylem and phloem.

What is the main characteristic of gymnosperms?

General Characters of Gymnosperms(gymnos-naked; sperma-seed)

They are the most primitive and simple seed plants. The seeds produced by these plants are naked and are not enclosed within fruits. Usually perennial, evergreen, and woody plants. Sporophylls are aggregated to form cones.

The plant life cycle consists of four stages; seed, sprout, small plant, and adult plant. When the seed gets planted into the soil with water and sun, then it will start to grow into a small sprout.

The stages that plants go through are from seed to sprout, then through vegetative, budding, flowering, and ripening stages.

Gymnosperms usually have needles that stay green throughout the year. Examples are pines, cedars, spruces and firs. Some gymnosperms do drop their leaves - ginkgo, dawn redwood, and baldcypress, to name a few.

Gymnosperms have a survival advantage over angiosperms only in extremely cold or dry conditions. This ability to survive cold or dry weather is due to a thick wax cuticle on the needles of conifers, which prevents dehydration through evaporative loss.

Reproductive Process

Upon landing on the female cone, the tube cell of the pollen forms the pollen tube, through which the generative cell migrates towards the female gametophyte through the micropyle. It takes approximately one year for the pollen tube to grow and migrate towards the female gametophyte.

The Four Stages of Life

Life consists of infancy, youth, the middle years and old age. Each stage is an important and beautiful time of growth, learning, caring and sharing in a special and unique way.

4 stage life cycle (complete metamorphosis). The four stages are egg, larva, pupa and adult.

A product life cycle consists of four stages: introduction, growth, maturity, and decline. A lot of products continue to remain in a prolonged maturity state. However, eventually, in every product life cycle, the product eventually phases out from the market.

What are the four major adaptations that evolved in gymnosperms?

Key adaptations involving retention of the megagametophyte within a protective coating to form a seed on the parent sporophyte, dissemination of the microgametophyte in durable pollen, production of complex root systems, and extensive development of secondary xylem in the stem, provided gymnosperms with opportunities ...

The Gymnosperms originated during the late Paleozoic era but flourished very well during Mesozoic era. Hence, the Mesozoic period is called as 'Age of Gymnosperms'.

The seed that originated in gymnosperms includes 3 generations of tissues: Seed coat and nucellus that arises from the sporophyte tissue, the gametophyte that will give nutrients, and the daughter sporophyte i.e. embryo itself.

The angiosperm life cycle consists of a sporophyte phase and a gametophyte phase. The cells of a sporophyte body have a full complement of chromosomes (i.e., the cells are diploid, or 2n); the sporophyte is the typical plant body that we see when we look at an angiosperm.

The life cycle of a gymnosperm involves alternation of generations, with a dominant sporophyte in which the female gametophyte resides, and reduced gametophytes. All gymnosperms are heterosporous. The male and female reproductive organs can form in cones or strobili.

The key difference between angiosperms and gymnosperms is how their seeds are developed. The seeds of angiosperms develop in the ovaries of flowers and are surrounded by a protective fruit. Gymnosperm seeds are usually formed in unisexual cones, known as strobili, and the plants lack fruits and flowers.

The main body of gymnosperms is sporophytic and diploid. However, their gametes are haploid. Due to this reason, they have a diplontic life cycle.

the pollen sac is the microsporangium, in which microspores are formed after meiosis of the microsporocyte. The microspores then undergo mitosis and give rise to pollen grains.

In gymnosperms, two types of spores are produced, so the haploid stage can start as either a male or female spore. The microspore is the small, male spore. This spore will undergo mitosis in order to produce the multicellular male gametophyte.

Compared to ferns, gymnosperms have three additional adaptations that make survival in diverse land habitats possible. These adaptations include an even smaller gametophyte, pollen, and the seed. Gymnosperms are plants that bear seeds that are "naked," meaning not enclosed in an ovary.

What is the function of gymnosperm?

Gymnosperms are a good source of food. Seeds of these non-flowering plants are widely used as an edible species, used for producing various food products. These plant species include: ginko, pinus, cycas, etc. A few species of gymnosperms are a good source of starch and are also used in the production of sago.

Habit and habitat :- The gymnosperm is represented by a perennial, evergreen, woody plant. Most of them are trees and some are shrubs. A few gymnosperms may be lianas or climbers. There are no herbs.

They are woody shrubs, trees or lianas and include no true aquatics and few epiphytes. Of some interest, gymnosperms include the tallest, the most massive, and the longest-living individual plants on earth. They are found throughout much of the earth, but form dominant vegetation in many colder and arctic regions.

The main types of plants in the gymnosperm group are conifers. Gymnosperms are plants that produce cones as their reproductive structures instead of producing flowers, as angiosperms do. The vast majority of gymnosperms are conifers such as pine trees.

Strobilus or cone is the reproductive structure of gymnosperms. Both male and female strobili can be present on the same (seen in Pinus) or on different trees (seen in Cycas). Gymnosperm plants are heterosporous. They produce different spores, which are the haploid microspores and megaspores.

Whereas ferns and mosses need free water to reproduce, gymnosperms, such as Ginkgo and cycads, produce their own fluid. In short, reproduction with archegonia requires an aqueous medium for sperm delivery. Eventually, gymnosperm groups evolved for which this fluid requirement was bypassed.

Most coniferous trees are evergreen and are specially adapted to survive in areas with lots of snow. Many are cone-shaped to help snow slide off them so the branches won't break. The leaves or needles of coniferous trees lose less water than other kinds of leaves. This also helps them survive.

Gymnosperms include most evergreen species such as pines, spruces and firs. Some gymnosperms, including larch and ginkgo, do lose their leaves in the winter. Gymnosperms are often called "conifers" since many of them produce seeds in cones, as well as "softwoods" since many of them have softer wood.

Gymnosperms do not have any flowers and seeds on the surface of scales and leaves. Strobilus is known as the structure of the gymnosperms. Both males and females can be considered under Pinus and Cycas. It contains two types of tissues known as the xylem and phloem.

(The period elapsed between the appearance of the ovulate cone and the maturation of pine seeds in those cones. Fertilization takes place about 1 year after pollination, and seed maturation takes several additional months).

What is the reproduction in gymnosperms?

In gymnosperms, a leafy green sporophyte generates cones containing male and female gametophytes; female cones are bigger than male cones and are located higher up in the tree. A male cone contains microsporophylls where male gametophytes ( pollen ) are produced and are later carried by wind to female gametophytes.