Flowers and Reproduction ( download (3) Stamens (androecium, filament,…
Flowers and Reproduction
fertilization or syngamy
alternation of generations
microspore mother cells
Embryo and Seed Development
stigma and pollen incompatibility
Monoecious and Dioecious species
True Fruits and Accessory Fruits
classification of fruit types
A seed is an embryonic plant enclosed in a protective outer covering. The formation of the seed is part of the process of reproduction in seed plants, the spermatophytes, including the gymnosperm and angiosperm plants.
Fragmentation in multicellular organisms is a form of asexual reproduction in which an organism is split into fragments. Each of these fragments develop into matured, fully grown individuals that are identical to their parents.
a mature haploid male or female germ cell which is able to unite with another of the opposite sex in sexual reproduction to form a zygote.
Sperm is the male reproductive cell. In the types of sexual reproduction known as anisogamy and its subtype oogamy, there is a marked difference in the size of the gametes with the smaller one being termed the "male" or sperm cell.
The egg cell, or ovum (plural ova), is the female reproductive cell (gamete) in oogamous organisms. The egg cell is typically not capable of active movement, and it is much larger (visible to the naked eye) than the motile sperm cells.
a diploid cell resulting from the fusion of two haploid gametes; a fertilized ovum.
A sporophyte is a multicellular diploid generation found in plants and algae that undergo alternation of generations. It produces haploid spores that develop into a gametophyte. The gametophyte then makes gametes that fuse and grow into a sporophyte. In many plants, the sporophyte generation is the dominant generation.
In biology, a spore is a unit of sexual or asexual reproduction that may be adapted for dispersal and for survival, often for extended periods of time, in unfavourable conditions. Spores form part of the life cycles of many plants, algae, fungi and protozoa
Fertilisation or fertilization, also known as generative fertilisation, insemination, pollination, fecundation, syngamy and impregnation, is the fusion of gametes to initiate the development of a new individual organism or offspring.
A gametophyte is one of the two alternating phases in the life cycle of plants and algae. It is a haploid multicellular organism that develops from a haploid spore that has one set of chromosomes. The gametophyte is the sexual phase in the life cycle of plants and algae
(especially in protozoans) the smaller of a pair of conjugating gametes, usually regarded as male.
megagametophyte. meg·a·ga·me·to·phyte. noun. The female gametophyte that arises from a megaspore of a heterosporous plant. In angiosperms, the megagametophyte is the embryo sac.
microgametophyte. [ mī′krō-gə-mē′tə-fīt′ ] The male gametophyte that develops from the microspores of heterosporous plants. The pollen grains of gymnosperms and angiosperms are microgametophytes. See more at gametophyte pollination.
Microspores are land plant spores that develop into male gametophytes, whereas megaspores develop into female gametophytes. The male gametophyte gives rise to sperm cells, which are used for fertilization of an egg cell to form a zygote.
Megaspores, also called macrospores, are a type of spore that is present in heterosporous plants. These plants have two spore types, megaspores and microspores. Generally speaking, the megaspore, or large spore, germinates into a female gametophyte, which produces egg cells.
Alternation of generations is the type of life cycle that occurs in those plants and algae in the Archaeplastida and the Heterokontophyta that have distinct sexual haploid and asexual diploid stages.
The diploid (2n) sporophyte and the haploid (n) gametophyte are clearly different in morphological structure
A pedicel is a stem that attaches a single flower to the inflorescence.
The receptacle refers to vegetative tissues near the end of reproductive stems that are situated below or encase the reproductive organs.
Complete flowers you can say Rose, Lily, Hibiscus etc. A complete flower has all four whorls: petals, sepals, pistil and stamen. A perfect flower has both male and female reproductive parts
An incomplete flower is defined as a flower missing any of its parts in its natural form, i. e. petals, sepals, stamens or pistils. A related term is "imperfect flower" indicating flowers that lack either stamens or pistils.
A sepal is a part of the flower of angiosperms. Usually green, sepals typically function as protection for the flower in bud, and often as support for the petals when in bloom. The term sepalum was coined by Noël Martin Joseph de Necker in 1790, and derived from the Greek σκεπη, a covering.
the sepals of a flower, typically forming a whorl that encloses the petals and forms a protective layer around a flower in bud.
Petals are modified leaves that surround the reproductive parts of flowers. They are often brightly colored or unusually shaped to attract pollinators. Together, all of the petals of a flower are called a corolla.
Together, all of the petals of a flower are called a corolla. Petals are usually accompanied by another set of special leaves called sepals, that collectively form the calyx and lie just beneath the corolla. The calyx and the corolla together make up the perianth.
The perianth is the non-reproductive part of the flower, and structure that forms an envelope surrounding the sexual organs, consisting of the calyx and the corolla.
DescriptionThe stamen is the pollen-producing reproductive organ of a flower. Collectively the stamens form the androecium.
the stamens of a flower collectively.
a slender threadlike object or fiber, especially one found in animal or plant structures.
the part of a stamen that contains the pollen.
microspore mother cell (microsporocyte) A diploid cell in plants that divides by meiosis to give rise to four haploid microspores (see sporophyll). In flowering plants microspore mother cells are formed within the pollen sacs of the anthers by mitosis; the microspores they produce develop into pollen grains.
a reflective layer of the choroid in the eyes of many animals, causing them to shine in the dark.
Pollen is a fine to coarse powdery substance comprising pollen grains which are male microgametophytes of seed plants, which produce male gametes.
the female reproductive organ of a flower, consisting of an ovary, a stigma, and usually a style. It may occur singly or as one of a group.
the female part of a flower, consisting of one or more carpels.
The part of the pistil where pollen germinates.
style takes on a whole new meaning. In plants, the style is a structure found within the flower. It is a long, slender stalk that connects the stigma and the ovary. The stigma is at the top of the style and is a sticky platform where pollen is deposited.
an ovary is a part of the female reproductive organ of the flower or gynoecium. Specifically, it is the part of the pistil which holds the ovule(s) and is located above or below or at the point of connection with the base of the petals and sepals.
part of the ovary wall to which the ovules are attached.
the part of the ovary of seed plants that contains the female germ cell and after fertilization becomes the seed.
the central part of an ovule, containing the embryo sac.
a cell of a bacterium or unicellular alga that is actively growing rather than forming spores.
a reproductive cell, especially a cell of an angiosperm pollen grain that divides to produce two male gamete nuclei.
a hollow tube which develops from a pollen grain when deposited on the stigma of a flower. It penetrates the style and conveys the male gametes to the ovule.
a cell inside the ovule of a flowering plant where fertilization occurs and which becomes the female gametophyte, containing the endosperm nucleus and the fertilized ovum that develops into the embryo.
characterizes the angiosperm female gametophyte (embryo sac or megagametophyte) in that it directly participates in "double fertilization" to initiate endosperm development, a feature distinguishing angiosperm from all other plant taxa.
either of the two nuclei of a seed plant embryo sac that are destined to form endosperm.
Antipodals are nutritive in function and they nourishes the embryo sac. Substances developed by the antipodal cells are helping in growth and development of endosperm. Generally, synergid cellas are located in female gametophyte and these are essential for angiosperm reproduction.
egg apparatus. A group of three cells in the seven-celled embryo sac of an angiosperm (flowering plant) consisting of the egg cell and two associated cells called synergids. The egg apparatus is located at the end of the embryo sac closer to the micropyle (the opening through which pollen nuclei enter the ovule.)
cells are two specialized cells that lie adjacent to the egg cell in the female gametophyte of angiosperms and play an essential role in pollen tube guidance and function.
Plasmogamy is a stage in the sexual reproduction of fungi, in which the cytoplasm of two parent cells (usually from the mycelia) fuses together without the fusion of nuclei, effectively bringing two haploid nuclei close together in the same cell.
Karyogamy is the final step in the process of fusing together two haploid eukaryotic cells, and refers specifically to the fusion of the two nuclei. Before karyogamy, each haploid cell has one complete copy of the organism's genome.
the triploid nucleus formed in the embryo sac of a seed plant by fusion of a sperm nucleus with two polar nuclei or with a nucleus formed by the prior fusion of the polar nuclei.
the action or process of fertilizing an egg, female animal, or plant, involving the fusion of male and female gametes to form a zygote.
the part of a seed which acts as a food store for the developing plant embryo, usually containing starch with protein and other nutrients.
a suspending part or structure: such as. a : a group or chain of cells that is produced from the zygote of a seed plant and serves to push the developing embryo into the endosperm.
an embryonic leaf in seed-bearing plants, one or more of which are the first leaves to appear from a germinating seed.
the radicle is the first part of a seedling to emerge from the seed during the process of germination. The radicle is the embryonic root of the plant, and grows downward in the soil. Above the radicle is the embryonic stem or hypocotyl, supporting the cotyledon. It is the embryonic root inside the seed
the region of an embryo or seedling stem above the cotyledon.
the part of the stem of an embryo plant beneath the stalks of the seed leaves or cotyledons and directly above the root.
Albuminous seeds are the seeds which have food stored in the special nourishing tissue called as endosperm that remains persistent till maturity. Cotyledons only act as food sucking organs and not food storage organs.e.g. Castor seed.
Exalbuminous seeds are the seeds which have the stored food and the cotyledons in a special structure called as kernel. It does not remain until the embryo is mature
the protective outer coat of a seed.
a fruit is the seed-bearing structure in flowering plants (also known as angiosperms) formed from the ovary after flowering. Fruits are the means by which angiosperms disseminate seeds.
the outer layer of the pericarp of a fruit.
the middle layer of the pericarp of a fruit, between the endocarp and the exocarp.
the innermost layer of the pericarp which surrounds a seed in a fruit. It may be membranous (as in apples) or woody (as in the stone of a peach or cherry).
the part of a fruit formed from the wall of the ripened ovary.
is when one plant pollinates a plant of another variety. The two plants' genetic material combines and the resulting seeds from that pollination will have characteristics of both varieties and is a new variety. Sometimes cross pollinating is used intentionally in the garden to create new varieties.
the pollination of a flower by pollen from the same flower or from another flower on the same plant.
There are commonly four distinct whorls of flower parts: (1) an outer calyx consisting of sepals; within it lies (2) the corolla, consisting of petals; (3) the androecium, or group of stamens; and in the centre is (4) the gynoecium, consisting of the pistils.
Imperfect flowers lack either stamens, the male parts or pistils, the female parts of the reproductive parts of the flowers. Usually these are found on what is called a dioecious plant, or one that bears male flowers on one kind of plant and female flowers on another.
A "perfect" flower has both stamens and carpels, and may be described as "bisexual" or "hermaphroditic". A "unisexual" flower is one in which either the stamens or the carpels are missing, vestigial or otherwise non-functional. ... Each plant produces either functionally male flowers or functionally female flowers.
The non-essential parts of a flower are sepals and petals. They are the non-reproductive parts of the flower.
Dioecy (Greek: διοικία "two households"; adjective form: dioecious) is a characteristic of a species, meaning that it has distinct male and female individual organisms. Dioecious reproduction is biparental reproduction.
monoecy (uncountable) (biology) The state of having both male and female sex organs; hermaphrodism. (botany) The condition of being monoecious, the state of having pistils and stamens on separate flowers of the same plan
the influence of closely associated species on each other in their evolution.
characterized by radial symmetry, such as a starfish or the flower of a daisy.
(of a flower) having only one plane of symmetry, as in a pea or snapdragon; bilaterally symmetrical.
Longitudinal section of female flower of squash showing pistil (=ovary+style+stigma), ovules, and petals. The petals and sepals are above the ovary; such a flower is said to have an inferior ovary, or the flower is said to be epigynous.
A superior ovary is an ovary attached to the receptacle above the attachment of other floral parts. A superior ovary is found in types of fleshy fruits such as true berries, drupes, etc. A flower with this arrangement is described as hypogynous.
(of a plant or flower) having the stamens and other floral parts at the same level as the carpels.
An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Morphologically, it is the modified part of the shoot of seed plants where flowers are formed.
In determinate (cymose) inflorescences, the youngest flowers are at the bottom of an elongated axis or on the outside of a truncated axis. At the time of flowering, the apical meristem (the terminal point of cell division) produces a flower bud, thus arresting the growth of the peduncle.
In indeterminate inflorescences, the youngest flowers are at the top of an elongated axis or on the centre of a truncated axis. An indeterminate inflorescence may be a raceme, panicle, spike, catkin, corymb, umbel, spadix, or head.
The structure known as a "fruit" is found only in the members of the Angiosperms. A fruit developed solely from the ovary and its contents is known as a true fruit.
An accessory fruit (sometimes called false fruit, spurious fruit, pseudofruit, or pseudocarp) is a fruit in which some of the flesh is derived not from the ovary but from some adjacent tissue exterior to the carpel. ... Fruit with fleshy seeds, such as pomegranate or mamoncillo, are not considered to be accessory fruit.
simple fruit. A fruit that develops from a single ovary in a single flower. Simple fruits may be fleshy or dry. There are three main kinds of fleshy simple fruit: the berry, the drupe, and the pome.
a fruit formed from several carpels derived from the same flower, e.g. a raspberry.
Fruits in which the coat becomes dry at maturity. Dehiscent Fruits - Dry fruits which at maturity open by definite natural means to shed the contained seeds.
in which the pericarp and accessory parts develop into succulent tissues, as in eggplants, oranges, and strawberries; and dry fruits, in which the entire pericarp becomes dry at maturity.