Reproduction in Lower and Higher Plants

Comprehensive vocabulary flashcards covering asexual and sexual reproduction in plants, including floral structures, pollination types, and embryonic development.

Reproduction

The production of young ones like parents, essential for the continuation of species and maintaining the continuity of life.

Clones

Morphologically and genetically identical individuals resulting from asexual reproduction.

Fragmentation

A process where multicellular organisms break into fragments that grow into new individuals, as seen in Spirogyra.

Budding

A common method of asexual reproduction in organisms like yeast and Protosiphon where outgrowths develop and separate into new individuals.

Zoospores

Flagellated, motile spores through which asexual reproduction occurs in Chlamydomonas.

Scion

The part of the stem containing more than one bud that is joined onto a rooted plant during grafting.

Stock

The rooted plant onto which a scion is joined during the process of grafting.

Dithecous

An anther that consists of two lobes.

Tetrasporangiate

A condition where an anther contains four pollen sacs (two in each lobe).

Tapetum

The innermost nutritive layer of the anther wall that encloses the sporogenous tissue.

Microsporogenesis

The process where each microspore mother cell divides meiotically to form a tetrad of haploid microspores (pollen grains).

Sporopollenin

A complex, non-biodegradable substance that makes up the thick outer layer (exine) of a pollen grain.

Germ-pores

Thin areas in the exine of a pollen grain meant for the growth of the emerging pollen tube during germination.

Apocarpous

A flower with many free carpels, such as in Michelia.

Syncarpous

A flower where many carpels are fused together, such as in Brinjal.

Anatropous ovule

The most common type of ovule in angiosperms where the micropyle is directed downwards and is adjacent to the funiculus.

Nucellus

The central parenchymatous tissue of the ovule surrounded by protective integuments.

Megasporogenesis

The process of formation of haploid megaspores from a diploid megaspore mother cell ($MMC$).

Filiform apparatus

Hair-like projections in synergid cells that guide the pollen tube towards the egg.

Monosporic development

A method where an embryo sac develops from a single functional megaspore.

Pollination

The transfer of pollen grains from the anther to the stigma of the flower.

Autogamy

A type of self-pollination in which a bisexual flower is pollinated by its own pollen grains.

Cleistogamy

A condition where flowers are self-pollinated even before they open, sometimes never opening at all.

Geitonogamy

The transfer of pollen grains to a stigma of a different flower produced on the same plant.

Xenogamy

A type of cross-pollination where pollen grains of one flower are deposited on the stigma of a flower of a different plant belonging to the same species.

Anemophily

Pollination by wind, common in crops like wheat, rice, and corn.

Hydrophily

Pollination by water, occurring in approximately $30$ genera of aquatic monocots.

Epihydrophily

A type of hydrophily where pollen grains float on the water surface to reach the stigma of female flowers, such as in Vallisneria.

Entomophily

Pollination by insects, characterized by large, showy, brightly colored flowers with nectar glands.

Ornithophily

Pollination by birds, which usually involves flowers that are brightly colored and secrete profuse, dilute nectar.

Chiropterophily

Pollination by bats, occurring in flowers that are dull-colored with strong fragrance and abundant nectar.

Protandry

A form of dichogamy where the androecium matures earlier than the gynoecium.

Protogyny

A form of dichogamy where the gynoecium matures earlier than the androecium.

Herkogamy

A mechanical device or physical barrier in a bisexual flower that prevents self-pollination by avoiding contact between sex organs.

Porogamy

The entry of the pollen tube into the ovule through the micropyle.

Siphonogamy

The process of fertilization where non-motile male gametes are carried through a hollow pollen tube.

Syngamy

The fusion of a haploid male gamete with a haploid female gamete (egg) to produce a diploid zygote.

Triple Fusion

The fusion of the second haploid male gamete with the diploid secondary nucleus to produce a triploid primary endosperm nucleus ($PEN$).

Mosaic Endosperm

An endosperm containing tissues of two different types/colors, forming a pattern as seen in corn.

Scutellum

The single shield-shaped cotyledon characteristic of a monocot embryo.

Coleoptile

The protective sheath of the plumule in a monocot embryo.

Coleorrhiza

The protective sheath of the radicle in a monocot embryo.

Perisperm

A persistent thin layer of nucellus in some seeds like black pepper and beet.

Dormancy

A temporary state of metabolic arrest that facilitates the survival of organisms during adverse environmental conditions.

Parthenocarpy

A condition where fruit is developed without the process of fertilization, resulting in seedless fruit.

Polyembryony

The occurrence of more than one embryo inside a seed, which results in the emergence of multiple seedlings.