Gymnosperms - Class IX

Gymnosperms are those seed plants in which the seeds remain exposed over the surface of the megasporophylls because the latter are not folded to form pistils and thus lack ovary. Flowers are absent and thus fruits are not formed.

Gymnosperms, example. Cycas, Pinus, Cedrus etc, bear reproductive structures in the form of cones. The cones that bear female reproductive structures are called female cones. Each female cone contains spirally arranged megasporophylls, that have ovules directly attached to them,  that is,ovules not enclosed in the ovary or are naked. After fertilization the ovule forms the seed and the ovary forms the fruit. Since, in gymnosperms ovary is  absent fruits are not formed.

Living gymnosperms are predominantly middle sized trees (Cycas) to tall trees (Pinus) and shrubs (Ephedra). Rarely they are woody climbers (Gnetum montanum). There are no herbs in gymnosperms.

Gymnosperms are those seed plants in which the seeds remain exposed over the surface of the megasporophylls because the latter is not folded to form pistils and thus lack ovary. Flowers are absent and thus fruits are not formed.

In gymnosperms, the pollen grains and the megaspores are haploid and develop as a result of meiosis in the respective mother cells. The functional megaspore forms the embryo sac. The endosperm is formed prior to fertilisation, hence is haploid.

In Gymnosperms, the male and female gametophytes do not have an independent free living existence. They remain within the sporangia retained on the sporophytes i.e., female gametophyte within megasporangium and male gametophyte within microsporangium.

The gymnosperms are comparatively more ancient than the angiosperms in
evolutionary terms. Most of the gymnosperms have now become extinct and
the group is presently represented by only 900 living species. The
living gymnosperms are widely distributed in the cold climates where
snow is the source of water. Cycas and Ginkgo are referred to as living
fossils .because they have not yet changed over the years while its
related members or species have become extinct or fossilised. The living
fossil represents a living unchanged example of an extinct group or
genera etc. So, the correct answer is 'Both A and B'.

Gymnosperms grow in cold and dry climates and they don't have a need for water as compared to angiosperms and the second reason is that they didn't evolve to have vessels and vessels are considered as an advanced element of xylem but exceptionally the order Gnetales (considered as advanced gymnosperms) have vessels in their xylem. Also, in cold climates vessels can be too efficient, because the fast draw on water can lead to air locks when water freezes. That’s why deciduous broad-leaved trees in temperate climates - that do have vessels - cut their losses by going dormant in the winter. 

 Bordered pits are especially common in the tracheids of some gymnosperms. Their structure can be discerned best in a cross-section through neighbouring cells. The middle lamina between the cells is preserved within the pits. Their centre is made up by a disc of primary cell wall material, called torus. No secondary walls exists in the pit's structure. 

In siphonogamy, pollen tubes are developed for the transfer of male cells to the eggs. The seed plants are siphonogamous. But in the lower plants male cell actually swim to the egg. As a consequence, spermatocytes are sometimes called siphonogamous. It is a characteristic of all spermatocytes. So the correct answer is option A.

 Phloem is the vascular tissue responsible for transport of sugars and other liquid materials. Phloem is composed of several cell types including sclerenchyma, parenchyma, sieve elements and companion cells. The function of companion cells is uncertain though it appears to regulate the activity of the adjacent sieve elements. Albuminous cells have a similar role to companion cells, but are associated with sieve cells only and are hence found in gymnosperms.

Gymnosperms are archegoniate spermatophytes. Spermatophyte is another term from phanerograms which are the seeded plants- gymnosperms and angiosperms. Archegonia is the female sex organ which is present in bryophytes, pteridophytes and gymnosperms. So, the gymnosperms are the only one which are both spermtophyte and archegoniate.

Gymnosperm undergo double fertilization, therefore in haploid stage of the gynosperm life cycle the plants have only one set of chromosome, thus haploid microspores are released into air as pollen and in gymnosperm endosperm is formed before fertilization from the female gametophyte(n). Hence it is haploid.

Gymnosperms lack typical companion cells and instead possess albuminous cells (or transfer cells) associated with sieve cells. The metabolic activity and functional control of the sieve elements in gymnosperms are regulated by the nucleus of these albuminous cells.

A male cone contains microsporophylls where male gametophytes ( pollen ) are produced and are later carried by wind to female gametophytes. The megaspore mother cell in the female cone divides by meiosis to produce four haploid megaspores; one of the megaspores divides to form the female gametophyte. So the correct option is 'Male and female gametophytes are independent of the sporophyte'.

Gymnosperms are vascular seed plants that include trees, shrubs, and lianas, but they do not form true herbaceous plants in the botanical sense of true herbs. Thus, herbs are the correct answer as they lack the woody persistent stems typical of gymnosperms.

The Gymnosperms originated during the late paleozoic era but floursihed very well during mesozoic era. Hence, the mesozoic period is called as 'Age of Gymnosperms'.

Gymnosperms are naked seed plants. The ovules are freely exposed before and after fertilisation.

The derivation of the word "gymnosperm" means naked seeds and is from the Greek words 'gymno' meaning naked or bare and 'sperm' meaning seed. 

The order Gnetales is considered to have several features that resemble angiosperms, such as the presence of vessels in the xylem and the structure of their reproductive organs.

Angiosperms and Gymnosperms resemble each other in many characteristics on of which is the presence of ovule. The difference lies in the appearance of ovule, in Angiosperm the ovule is enclosed in ovary, whereas in Gymnosperms the ovule is naked. 

Heterospory is the production of spores of two different sizes and sexes by the sporophytes of land plants. Gymnosperms, like all vascular plants, have a sporophyte-dominant life cycle. The gametophyte is relatively short-lived. Two spore types, microspores and megaspores, are typically produced in pollen cones or ovulate cones, respectively. 

Zoodiogamy is a type of fertilization in plants, wherein the male gametes or antherozoids swim in a film of water to the female gametes present in the archegonium. This type of plant reproduction relates to evolution and  is found in lower gymnosperms besides algae, bryophytes and pteridophytes.

"Gymnosperms" include all seed plants other than the angiosperms, or flowering plants. The absence of an enclosing structure is believed to be primitive, thus the first seed plants were "gymnosperms. 

The term Spermatophyta refers to any of a group of higher plants, that produce seeds.  

Gymnosperms refers to the group of naked seed bearing vascular  plants. Their seeds are naked as these are not enclosed in an ovary, like that of the angiosperms. This group includes large trees, like the pines, conifers, cycads and Ginkgo. 

The "endosperm" is a tissue in which the nutrient substances necessary for the development of the embryo are deposited. In gymnosperms the endosperm is formed in the ovule during germination of the megaspore is a gametophytic tissue, which consequently becomes the female prothallus or the gametophyte with a haploid set of chromosomes. The archegonia in gymnosperms develop from certain cells of the endosperm.

In gymnosperms, below micropylar beak some of the cells of nucellus of ovule disintigerate to form pollen chamber.

Cryptogams are plants that reproduce via spores and do not produce seeds or flowers. Phanerogams are seed-bearing plants (including gymnosperms and angiosperms).

Gymnosperms are called 'naked-seeded' because their ovules are not enclosed within an ovary wall, and therefore they do not form fruits after fertilization.

In gymnosperms, the pollen chamber is a cavity formed in the nucellus of the ovule where pollen grains land and rest before germination.

Gymnosperms are wind-pollinated plants. They do not have to cover around seeds. They do not produce fruits or flowers. After pollination, they produce pollen tubes. This pollen tube carries the sperm cells to the egg. These eggs are located within the integument megasporangium. So, all these are the characteristics of gymnosperms.

Gymnosperms are woody, ever green trees. They are found where snow is the source of water and not rains. Their dominant plant body is sporophyte. It is differentiated into roots, stems and leaves. They are xerophytic due to presence of thick bark, scales, cuticles, sunken stomata etc.

The rachis and leaflet have diploxylic vascular bundles. At the region ofthe stem cortex, the leaf trace has only centrifugal xylem, hence, it is endarch. These traces enter the leaf as the rachis separates, the centripetal xylem appears and it is in the exarch condition. The leaflet has a single midrib bundle and is in the diploxylic condition.

Phanerogams, also known as spermatophytes, refer to "all seed plants". Gymnosperms are the seed bearing plants wherein seeds are naked i.e. not enclosed by ovary or fruit. Angiosperms are seed bearing plants wherein seeds are enclosed within ovary or fruit. Since both gymnosperms and angiosperms are seed-bearing plants and therefore are included under phanerogams. Pteridophytes (ferns) are categorized under cryptogams, not under phanerogams, as they do not form seed or flowers. Thus, the correct answer is option D.

Both gymnosperms and angiosperms are seed-bearing vascular plants. Gymnosperms are the seed bearing plants wherein seeds are naked i.e. not enclosed by ovary or fruit. Angiosperms are seed bearing plants wherein seeds are enclosed within ovary or fruit. Both have a well-differentiated stem, root and leaves. Thus, the correct answer is option B.

Endosperm in gymnosperms is formed before fertilization and is always haploid.

Bordered pits xylem tracheids are common in gymnosperms.

Vessels are limited in growth, are joined end to end to form continuous tubular structures with perforations in their cross walls. Water and minerals are efficiently conducted through these perforations. Vessels are present in most of the angiosperms. Tracheids are elongated and non-perforated. They have only pit pairs, at the regions of union with other tracheids. Conduction of water and minerals is not as efficient as in vessels. Tracheids are found in most of the gymnosperms.
Thus, the correct answer is option A.

In gymnosperms, the endosperm is formed before fertilization from the female gametophyte, making it haploid. In angiosperms, it is formed after fertilization via triple fusion, making it triploid.

Gingko biloba, commonly called as gingko, is an endangered genus belonging to division Gymnosperm. It is also a living fossil, as it is the sole survivor of a group of trees that belonged to an era of dinosaurs. The trees rich up to 40 meters in height. It is a deciduous conifer because it sheds its leaves annually. It is found in deciduous forests and valleys. 

The endosperm in gymnosperms is part of the female gametophyte, which develops into the endosperm before fertilization occurs.

Gymnosperms typically lack xylem vessels (except in Gnetales) and companion cells (they have albuminous cells instead).

Gymnosperms and angiosperms (like maize) are seed plants that use pollen tubes for fertilization, meaning they do not require external water for the sperm to reach the egg.

Plants that produce seeds but lack flowers and fruits are classified as gymnosperms.

Gymnosperms do not have antheridia; they produce pollen grains (microspores) that develop into male gametophytes.

The defining characteristic of gymnosperms is the presence of 'naked seeds', meaning the seeds are not enclosed in an ovary.

Cycas is a genus of gymnosperms, which are characterized by having naked seeds.

In gymnosperms, the ovules are exposed on the surface of megasporophylls and are not enclosed by an ovary wall, thus they are 'naked'.

The pericarp is the part of the fruit that develops from the ovary wall. Since gymnosperms lack an ovary, they lack a pericarp, leaving the seeds naked.

Gymnosperms are a diverse group of seed plants with approximately 1000 living species. The other values provided are estimates that do not align with current botanical consensus.

A protostele is the simplest and most primitive type of stele, characterized by a solid central core of xylem surrounded by a layer of phloem. It lacks a central pith.

During the Mesozoic era, specifically the Jurassic period approximately 200 million years ago, gymnosperms were the dominant land plants before the rise of angiosperms.

Gymnosperms are defined as seed-bearing vascular plants where the seeds are not enclosed within an ovary or fruit. Bryophytes lack vascular tissue, and pteridophytes do not produce seeds.

Gymnosperms, particularly cycads, are known for having the largest ovules and the largest male gametes among seed plants. They also include some of the largest tree species.

Polyembryony, the development of more than one embryo in a single seed, is a common feature in gymnosperms, often occurring through cleavage of the proembryo or the presence of multiple archegonia.

The defining characteristic of gymnosperms compared to pteridophytes is the production of seeds, specifically 'naked' ovules that are not enclosed in an ovary. Pteridophytes produce spores, not seeds.

While most seed plants have non-motile sperm, primitive gymnosperms like Cycads and Ginkgo retain flagellated, motile sperm (ciliated stage).

Gymnosperms are spermatophytes, meaning they produce seeds, and these seeds are 'naked' because they are not enclosed within an ovary wall or fruit.

Gymnosperms are called naked-seeded plants because they lack an ovary, which in angiosperms develops into the fruit wall enclosing the seeds.

Gymnosperms are seed-producing plants that do not produce flowers or fruits, distinguishing them from angiosperms.

Gymnosperm xylem typically consists of tracheids. The presence of vessels is a characteristic feature of angiosperms, not gymnosperms (with rare exceptions like Gnetales).

The term naked seed refers to the absence of an ovary wall, which would otherwise enclose the seed in a fruit.

In gymnosperms, the pollen chamber is a space formed in the nucellus of the ovule where pollen grains are received and germinate before fertilization.

Gymnosperms are heterosporous (c is true). The female gametophyte is multicellular and retained within the megasporangium (b is true). The gametophytes are not independent (a is false).

Pinus longaeva (Great Basin bristlecone pine) is widely recognized as one of the oldest living tree species, with individuals living over 4,000 to 5,000 years.

Gymnosperms are vascular plants that produce seeds but lack the ovary and fruit characteristic of angiosperms.

Gymnosperm wood is typically 'non-porous' because it lacks true vessels, which are the structures that create the 'pores' seen in angiosperm wood.

This appears to be a duplicate of question 496472 with the same options reordered. Gymnosperm wood lacks vessels and is non-porous, while porous woods are characteristics of angiosperms.

Sequoia sempervirens (Coast Redwood) is the tallest tree species in the world and belongs to the gymnosperms.

In gymnosperms, the gametophytes are reduced and dependent on the sporophyte, meaning they do not have an independent free-living existence.

The term 'gymnosperm' was coined by the Greek philosopher Theophrastus to describe plants with naked seeds.

Transfusion tissue is a specialized tissue found in the leaves of gymnosperms, particularly in conifers and cycads, to assist in the conduction of water and nutrients.

Transfusion tissue is specifically located in the leaves of gymnosperms, where it facilitates the movement of water between the vascular bundles and the mesophyll cells.

Gymnosperms are plants with produce seeds but lacks flower. These are non flowering plants. They produce naked seeds.

Sequoia is one of the tallest trees. It is also known as the redwood tree. Leaves of gymnosperms are well adapted to the extreme of climate. Gymnosperms are heterosporous. They have both pollen and tubules. Salvinia is a pteridophyte whereas Ginkgo and Pinus are gymnosperms.

Ginkgo is a gymnosperm, a naked seeded plant in which seed is not enclosed inside the fruit. It is a dioecious plant in which the male and female species do not grow and produce reproductive organs at the same time. First, the female trees produce their seeds and then after four months, the pollen is produced to fertilize the female plant. Generally, the female plant produces two ovules both of which develop into seeds. The fertilization of seeds occurs via motile sperms. The fertilization occurs generally before or after the seeds are shed in autumn.

Thus, the correct answer is 'Ginkgo'.

Gymnosperms are seed bearing plants. They are flowerless plants. Most of the gymnosperms are vesselless. They do not have vessels in their xylem. The only division which have vessels is Gnetophytes. Gnetophytes having vessel include Genus Gnetum, Ephedra and Welwitschia. 

Gymnosperms do not have vessels in their xylem. Water conducting tissues present in them are tracheids.

Unlike bryophytes and pteridophytes, in gymnosperm, the male and female gametophytes don't have an independent free-living existence. They remain attached to the sporophytes. After fertilization, these developed into an embryo and the ovule into seeds. Seeds are not covered. So 3 generation live inside one seed of gymnosperm- the embryo and the female gametophytic tissue and the seed coat and the nucellus which is the female sporophytic tissue.

Gymnosperms are seed-bearing vascular plants like cycads, conifers, yews and ginkgo in which the ovules are not enclosed in an ovary. So, the ovules are called naked. 

Gymnosperms are the plants in which the ovules are not covered by an ovary, and the plant does not bear flowers. The seeds are naked.

Gymnosperms and angiosperms, sperm cells have no cilia. All other motile land plant sperm cells are released into the environment.

• The endosperm is the storage tissue in the seeds of gymnosperms.
• The genotype obtained in the $F _1$ generation will be Tt, when a homozygous gymnospermic plant (TT) is crossed with another (tt).
• Thus, the embryo being diploid in nature will have the genotype Tt.
• Whereas, the genotype of the endosperm will be TTt because it is triploid in nature. 

There are no archegonia in Gnetales. Hence, there will be no neck canal cells.

The total number of living gymnosperms of the world is about 850 species, belonging to 79 genera of 15 families. Although the number of species of gymnosperms accounts for only 0.36% of that of the angiosperms, they have formed large areas of various kinds of coniferous forests and are widely distributed all over the world, especially on mountains from middle to alpine latitudinal zones in cold-temperate and subtropical latitudes of the Northern hemisphere.

Sieve cells can be traced in gymnosperms and pteridophytes. Sieve cells are typically associated with gymnosperms because angiosperms have the more derived sieve tube members and companion cells in their phloem. They have a narrower diameter and are more elongated compared to sieve tube members. Sieve cells are associated with albuminous cells, which lack starch thus, making it possible to differentiate them from phloem parenchyma.
Therefore, the correct answer is option C.

The resin duct in Gymnosperms are formed by separation of cells to form a cavity. The cells surrounding this cavity secrete resin into the cavity. Resin is aromatic and prevents infection. 

The gymnosperms do not have petals or flowers, but they do produce seeds. The name 'Gymnosperm' means, 'naked seeds' and refers to the fact that the gymnosperms bears their seeds on the margins of modified leaves or cones. 

In Gymnosperms the fertilized ovule does not develop into a fruit as it would in an angiosperm. Because gymnosperms have no ovary, they can never produce fruit. Seeds develop from the ovules that are found in the developed ovaries or fruit, but in the case of gymnosperms, the ovules are located directly on the surface of the flower or cone. Yews and ginkgoes develop fruit like structures, but their seed is not inside these organs, which makes them Gymnosperms.

Gymnosperms are seed bearing non flowering plants. Since gymnosperms have no ovaries, they do not produce real fruits, at least not in the botanical sense. Because no fruit tissue surrounds gymnosperm seeds, the seeds are said to be "naked." 
In Gymnosperms vascular tissues are arranged into vascular bundles just like Angiosperms. However, xylem does not possess vessels and phloem is without companion cells, like pteridophytes.

A perennial plant or simply perennial is a plant that lives for more than two years. 

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. Gymnosperms include one of the world's tallest trees, Sequoia sempervirens.

Megasporangium or ovule is borne on adaxial or upper surface of megasporophyll or ovuliferous scale and are generally orthotropous and unitegmic in gymnosperms but are bitegmic in the Gnetales.

The gymnosperms are a group of seed-producing plants that do not produce flowers. These include conifers, cycads, Ginkgo, and gnetales. Though they are seed bearing their seeds are not enclosed in ovary they make up for about 700 species of woody plants with most of them being trees and some shrubs. A few gymnosperms however may lianas or climbers. However, there are no herbs in the group.

Fruits are not formed in gymnosperms due to absence of ovary. The ovules of a gymnosperm do not develop in an ovary but are "naked". Seeds develop from the ovules that are found in the developed ovaries but in the case of gymnosperms, the ovules are located directly on the surface of the flower or cone. 

Gymnosperms and angiosperms are the phenerogames or spermatophytes. 

Gymnosperms are the most primitive of the seed plants. A seed comprises two parts: an endosperm, which nourishes the embryo, and the embryo itself, which is fed by the endosperm.

The sporophyte (2n) phase is the longest phase. The gametophytes (1n), microspores and megaspores, are reduced in size. This phase may take more than one year between pollination and fertilization, while the pollen tube grows towards the megasporocyte (2n), which undergoes meiosis into megaspores. The megaspores will mature into eggs (1n) .
Gymnosperm seed is made up of three generations of tissues. 
1) maternal sporophyte tissue (seed coat and nucellus), 
2) gametophyte 
3) daughter sporophyte (embryo)

Gymnosperms were the first plants to have seeds. They are often referred to as having naked seeds because they do not have flowers and they develop on the surface of the reproductive structures of the plants rather than being contained in a specialized ovary. These seeds are often found on the surface of cones and short stalks.

Gymnosperms are a group of plants with the following unique characteristics:

• They do not have an outer covering or shell around their seeds.
• They do not produce flowers.
• They do not produce fruits.
• They are pollinated by the wind.

Gymnosperms are more ancient than angiosperms. They formed dominant vegetation on the earth about 200 million years ago, and have been replaced by the angiosperms with the changing time and climatic conditions. They are now maintaining their dominance only in the colder regions, where instead of rain, snow is the source of water. Only a few gymnosperms, like cycads thrive in warm whether.

In Pinus, the dwarf shoots are specialized branches of limited growth. They are typically shed after 2 to 3 years.

In gymnosperms, the pollen grain typically produces two male gametes. These are formed during the development of the male gametophyte.

Gymnosperm endosperm is haploid because it is formed from the female gametophyte tissue before fertilization. In contrast, angiosperm endosperm is triploid and forms after fertilization via double fertilization.

Gymnosperms are vascular plants that lack true vessels in their xylem and companion cells in their phloem, which are characteristic features of angiosperms.

The secondary xylem in gymnosperms does not contain vessels. So it is called soft wood or non-porous wood.

The secondary xylem or wood of gymnosperms, vessels are absent. So it is called non porous wood.

So, the correct option is ‘lacks vessels’.

Gymnosperms like Cycas and Ginkgo retain ciliated, motile male gametes. While most advanced spermatophytes have lost this trait, it persists in these primitive gymnosperm groups.

Both pteridophytes and gymnosperms produce archegonia as the female sex organ. They differ in that gymnosperms produce seeds and have ovules, while pteridophytes generally do not.

Cedrus is a gymnosperm. In gymnosperms, male and female gametophytes do not have free independent existence. They remain within the sporangia retained on the sporophytes. 

The gymnosperms are the plants in which the ovules are not enclosed by an ovary wall and remain exposed, both before and after fertilization. This is that developers fertilization are not covered that is they are naked.

Gymnosperm generally lacks xylem vessels and companion cells in phloem as it grows in a cold and dry climate and they didn't evolve to have vessels and vessels are considered as advanced elements of xylem. And companion cells in phloem assist active transport of minerals which is absent in Gymnosperm.

Gymnosperms have no ovary, they can never produce fruit.