Asexual reproduction is the process resulting in the production of genetically identical progeny from a single organism, without the fusion of gametes, leading to clones that inherit the genes of the parent.
Gibberellins can induce parthenocarpy artificially by promoting fruit development without fertilization, which can be achieved through methods like spraying gibberellins or delaying pollination.
The testa is the typical outer seed coat that protects the seed.
The second mitotic division is concerned with the generative cell only and gives rise to two non-motile male gametes.
Polar nuclei are two nuclei that migrate towards the center of the embryo sac and are formed during the development of the female gametophyte.
Geitonogamy is the transfer of pollen grain to a stigma of a different flower produced on the same plant. It is functionally similar to cross pollination but does not bring about genetic variations.
The female reproductive whorl of a flower is called the gynoecium (Pistil).
A flower with many free carpels is called apocarpous.
It is a mechanism in which anthers and stigmas mature at different times in a bisexual flower to prevent self-pollination.
Recurrent apomixis is a type of apomixis where the embryo sac arises from an archesporial cell or another part of the nucellus, often involving diplospory.
Parthenocarpy is the condition in which fruit develops without fertilization, resulting in seedless fruits. It occurs naturally in some varieties of plants like Pineapple, Banana, and Papaya, often due to the production of auxin in the unfertilized ovary.
Agamospermy is the process where seeds are produced without meiosis and syngamy, meaning the embryo develops without the typical fertilization process.
Antipodal cells are a group of three cells present at the chalazal end of the embryo sac in angiosperms.
The cellular type of endosperm is formed when the division of the triploid primary endospermic nucleus is immediately followed by wall formation, resulting in a cellular structure from the beginning.
Pollination is the transfer of pollen grains from the anther to the stigma of a flower, which is a prerequisite for fertilization.
Ornithophilous flowers are usually brightly colored, large, and showy; they secrete profuse, dilute nectar; pollen grains are sticky and spiny; and they are generally without fragrance due to birds' poor sense of smell.
The function of a flower is to produce haploid gametes and ensure that fertilization takes place.
Double fertilization is a complex fertilization mechanism in flowering plants where one male gamete fuses with the egg to form a diploid zygote, while the second male gamete fuses with the diploid secondary nucleus to form the primary endosperm nucleus.
Anemophily is pollination by wind, where plants like wheat, rice, and corn are primarily wind-pollinated.
Mosaic endosperm is a type of endosperm that contains tissues of two different types, often resulting in a patchy or mosaic pattern, as seen in plants like corn.
Double fertilization ensures that the parent plant invests in a seed with a food store only if the egg is fertilized, thus optimizing resource allocation.
Spore formation is a method of asexual reproduction where organisms like Chlamydomonas produce flagellated, motile zoospores that can grow independently into new individuals.
Perisperm is a thin, papery layer that may persist in some genera, such as black pepper and beet, derived from the nucellus in the ovule.
It is a type of dichogamy where the androecium matures earlier than the gynoecium, preventing self-pollination.
Polyembryony is the development of more than one embryo inside a seed, resulting in the emergence of multiple seedlings. It was first observed in the Citrus genus and can be classified as true or false depending on the origin of the embryos.
Monosporic development is the method of embryo sac development from a single megaspore.
Clones are morphologically and genetically identical individuals produced through asexual reproduction, inheriting the genes of the parent organism.
Homogamy is when the anther and stigma of a flower mature at the same time, facilitating self-pollination.
The Hypocotyl is the part of the embryo that develops into the stem below the cotyledons.
The zygote is the fertilized egg that develops into the embryo after fertilization.
It is a mechanical device that prevents self-pollination by creating a natural physical barrier between the two sex organs in a bisexual flower.
Pollen grain is the odd one out.
Pollination and seed formation are crucial because they initiate the development of fruits, which are essential for the reproduction of flowering plants.
Micropropagation is a method of carefully growing plants to produce many plantlets, often used in modern horticulture.
Nucellar embryos are significant because they allow for the production of genetically uniform parental type seedlings, which can be beneficial in horticulture.
The four different whorls of a typical flower are calyx, corolla, androecium, and gynoecium.
Megasporogenesis is the process of formation of haploid megaspores from a diploid megaspore mother cell (MMC).
The tegmen is the inner thin, membranous covering of the seed.
The three parts of a typical carpel are the ovary, style, and stigma.
Endospermic seeds, also known as albuminous seeds, are those in which the food reserves in the endosperm are partially used up during the development of the embryo, remaining conspicuous in the mature seed.
The funiculus is the stalk of the seed that connects the seed to the ovule before seed formation.
Pollination syndromes are co-evolved physical characteristics of plants and pollinators that facilitate successful interactions for pollination.
The scutellum is the single shield-shaped cotyledon found in monocot embryos, occupying the terminal position.
The Endosperm provides nourishment to the developing embryo and is consumed as the embryo matures.
Coleorhiza is the protective sheath that covers the radicle in monocot embryos.
Insect pollinated flowers usually possess sticky pollens with a rough surface.
Megasporogenesis is the process of formation of megaspores from the megaspore mother cell.
The ovary develops into fruits and the ovules develop into seeds.
The triploid endosperm is a nutritive tissue that develops from the triploid primary endosperm nucleus, which divides mitotically to provide nourishment to the developing embryo.
Xenogamy is a type of cross pollination where pollen grains from one flower are deposited on the stigma of a flower of a different plant belonging to the same species, generating genetically varied offspring.
Pollen grains in hydrophilous flowers are long, unwettable due to mucilage, and have a specific gravity equal to that of water, allowing them to float.
Apomixis is the phenomenon of embryo formation through asexual reproduction without the formation of gametes or fertilization.
Autogamy is a type of self-pollination where a bisexual flower is pollinated by its own pollen grains, resulting in genetically identical offspring.
Embryogenesis is the process of development of the zygote into an embryo, occurring at the micropylar end of the embryo sac.
An individual member of the androecium, consisting of a filament, connective, and anther.
A syncarpous flower is one that has many carpels fused together.
An anatropous ovule is a type of ovule in which the micropyle is directed downwards and is adjacent to the funiculus.
Pollination contrivance refers to adaptations that plants develop to encourage specific pollinators, enhancing successful interactions between plants and their pollinators.
The embryo sac is the female gametophyte, an oval, multicellular structure embedded in the nucellus.
Chalazogamy is the entry of the pollen tube into the ovule through the chalaza.
The zygote divides to form a two-celled proembryo, consisting of a basal suspensor initial cell and a terminal embryonal initial cell.
Synergids secrete chemicals that guide the growth of the pollen tube and facilitate the entry of male gametes into the embryo sac.
Sepals are green structures that protect the flower until it opens.
An embryo sac is a seven-celled and eight-nucleated structure formed during the development of the female gametophyte in angiosperms.
Abiotic agents are non-living agents that facilitate pollination, including wind and water.
Grafting is a method where parts of two plants are joined so that they grow as one plant, typically involving a scion and a stock.
The nuclear type of endosperm is characterized by the primary endosperm nucleus dividing mitotically without wall formation, producing a large number of free nuclei.
Non-recurrent apomixis involves the usual meiotic division of the megaspore mother cell, forming a haploid embryo sac, with embryos arising from parthenogenesis or apogamy.
Refers to an anther that has four pollen sacs.
The Radicle is the part of the embryo that develops into the root.
A complex, non-biodegradable substance that makes up the thick outer layer (exine) of pollen grains.
The generative cell undergoes mitotic division to produce male gametes within the pollen grain.
Colored petals attract insects that carry pollen, facilitating pollination.
Geitonogamy requires a pollinator but results in genetically similar offspring to autogamy.
Endosperm is formed by the fusion of polar nuclei and a male gamete.
Seed viability refers to the length of time seeds remain healthy and capable of germination under suitable conditions.
Budding is a common method of asexual reproduction in unicellular yeast, where one or more outgrowths (buds) are produced during favorable conditions, which then separate and develop into new individuals.
Hypohydrophily is a type of hydrophily where pollination occurs below the water surface, with pollen grains that are heavier than water sinking to reach the stigmas of female flowers.
Chiropterophily refers to pollination by bats, which can transport pollen over long distances, sometimes several kilometers.
Hydrophilous flowers are small, inconspicuous, have unwettable floral parts, and lack nectar and fragrance.
An immature anther is made of parenchymatous tissue surrounded by a single-layered epidermis, generally dithecous and tetrasporongiate.
Unisexuality, also known as dioecism, is when a plant bears either male or female flowers, preventing self-pollination.
The funiculus is a small stalk that attaches the ovule to the placenta.
It is a phenomenon where pollen grains from other flowers germinate more rapidly on the stigma than pollen grains from the same flower.
The Hypophysis is the lowermost cell of the suspensor that plays a role in the development of the root cap.
The tapetum is the innermost nutritive layer of the anther wall that encloses the sporogenous tissue.
Double fertilization was discovered by Nawaschin in liliaceous plants such as Lilium and Fritillaria.
The ovary is the part of the flower where fertilization occurs after the pollen tube traverses down to it.
The tapetum layer supplies nourishment to developing pollen grains.
Sexual reproduction involves the fusion of two compatible gametes or sex cells, leading to the formation of a diploid zygote and genetically dissimilar offspring.
The major events in sexual reproduction are meiosis and the fusion of gametes to form a diploid zygote.
Syngamy is the process of fusion between a haploid male gamete and a haploid female gamete, restoring the diploid condition.
Dormancy is a state of metabolic arrest that allows seeds to survive adverse environmental conditions, preventing germination even in favorable conditions.
Synergids are supporting haploid cells that help guide the pollen tube towards the egg cell through hair-like projections called filiform apparatus.
Chiropterophilous flowers are dull colored with strong fragrance, secrete abundant nectar, and produce large amounts of edible pollen grains.
Adventive embryony is when embryos develop from somatic nucellus or integuments alongside the normal zygotic embryo, leading to polyembryony.
Non-endospermic seeds, or ex-albuminous seeds, are those in which the embryo absorbs all the food reserves from the endosperm during development, resulting in the endosperm disappearing in mature seeds.
The helobial type of endosperm occurs when the first division of the primary endosperm nucleus is followed by a transverse wall, creating unequal cells, with subsequent free nuclear divisions.
Porogamy is the entry of the pollen tube into the ovule through the micropyle.
The inner integument is a layer that surrounds the ovule and contributes to the formation of the seed coat after fertilization.
Pollination is the transfer of pollen grains from the anther of a flower to the stigma of the same or a different flower.
No, pollination and fertilization are not necessary in apomixis.
The filiform apparatus helps guide the pollen tube to the ovule.
Epihydrophily is a type of pollination where pollen grains float on the water surface and reach the stigma of female flowers, as seen in plants like Vallisneria.
Vegetative reproduction is a form of asexual reproduction where plants reproduce through their vegetative parts, resulting in genetically identical offspring.
Compatibility determines which pollen grains are accepted or rejected by the pistil, based on special proteins that recognize compatible pollen of the same species.
Entomophily is a type of pollination that occurs with the help of insects, involving flowers that are large, brightly colored, and produce sweet odors and nectar.
Syngamy is the fusion of a haploid male gamete with a haploid female gamete (egg) to produce a diploid zygote.
The Suspensor is a structure formed from the suspensor initial cell that helps push the embryo into the endosperm.
Vegetative propagation is a form of asexual reproduction in plants where new individuals are produced from vegetative parts such as roots, leaves, or stems.
Biotic agents, including insects, birds, bats, and snails, help transfer pollen from one flower to another, facilitating plant reproduction and sustaining ecosystems.
The Embryonal initial is the smaller cell in the two-celled proembryo that undergoes divisions to form the embryonic structures.
Fruits provide nourishment to developing seeds, protect seeds in their immature condition, and develop special devices for seed dispersal.
A typical pollen grain is a non-motile, haploid, unicellular body with a single nucleus, surrounded by a two-layered wall called sporoderm.
Pollen viability depends upon environmental conditions of temperature and humidity.
Coleoptile is the protective sheath that covers the plumule in monocot embryos.
Meiosis occurs in the megaspore mother cell.
The stigma determines the compatible nature of pollen grain.
Hydrophily is the pollination mechanism where pollen is transferred by water.
It is the interaction of pollen grains with sporophytic tissue (stigma), beginning with pollination and ending with fertilization, involving the recognition and acceptance of compatible pollen by the pistil.
The male reproductive whorl of a flower, consisting of stamens.
An Oospore is the initial zygote formed after fertilization, which develops into the embryo.
Outbreeding devices are mechanisms that discourage or prevent self-pollination to promote cross-pollination and increase genetic diversity, essential for evolution by natural selection.
Fragmentation is a method of asexual reproduction where multicellular organisms break into fragments, which can grow into new individuals, as seen in organisms like Spirogyra.
Tissue culture is a method of propagating plants by using a small amount of plant tissue to grow new plants.
Triple fusion is the process where the second haploid male gamete fuses with the diploid secondary nucleus to produce the primary endosperm nucleus, which develops into triploid endosperm.
The development of a dicot embryo involves the formation of a zygote from the fertilization of an egg by a male gamete, followed by cell divisions that lead to the formation of the embryo and the surrounding structures.
The process where each microspore mother cell divides meiotically to form a tetrad of haploid microspores (pollen grains).
The hilum is the scar of the ovule that remains after the seed has formed, marking the point of attachment to the funiculus.
It refers to the presence of two or three forms of flowers in some plants, where stigmas and anthers are placed at different levels to prevent self-pollination.
Mesogamy is the entry of the pollen tube into the ovule by piercing the integuments.
It is a genetic mechanism that inhibits the germination of pollen on the stigma of the same flower, preventing self-fertilization.
The ploidy level is NOT the same in the secondary nucleus and endosperm.
Cleistogamy is a condition where some flowers self-pollinate even before opening, often seen in underground flowers.
Siphonogamy refers to the process where non-motile male gametes are carried through a hollow pollen tube to ensure fertilization takes place.
Chasmogamous flowers are those that open to expose their sex organs, allowing for pollination.
The micropyle is a small pore in the seed coat that allows the entry of water and oxygen during soaking.
The Plumule is the part of the embryo that develops into the shoot and leaves.
Fertilization in plants occurs when one male gamete fuses with the egg or ovum, leading to the formation of a zygote.
The receptacle is the base of the flower to which other floral parts are attached.
The endosperm will have 6 chromosomes.
There are seven haploid cells present in a mature embryo sac.
Incompatibility acts as a natural barrier preventing the fusion of gametes from different species, ensuring species integrity.
It is a type of dichogamy where the gynoecium matures earlier than the androecium, also preventing self-pollination.
Pericarp is the part of the fruit that develops from the ovary wall after fertilization, typically consisting of three layers in fleshy fruits.
Germ-pores are thin areas in the exine that allow for the growth of the emerging pollen tube during germination.
At least 20 pollen grains are required because each pollen grain has 2 male gametes, and not all will successfully fertilize an ovule.
Parthenocarpy is the development of fruit without fertilization.
Double fertilization involves the fusion of one male gamete with the egg cell to form the zygote and another male gamete with two polar nuclei to form the triploid endosperm.
Polyembryony can be commercially exploited by producing multiple embryos from a single fertilized ovule, leading to more plants.
The stages include microspore formation, mitotic division to form pollen grains, and development into mature male gametophytes.
Three devices include dichogamy, herkogamy, and self-incompatibility mechanisms.
