Sexual Reproduction in Flowering Plants - Vocabulary Flashcards

Flashcards for reviewing key vocabulary from a Biology lecture on sexual reproduction in flowering plants.

Angiosperms

Flowering plants that exhibit sexual reproduction, forming fruits and seeds as end products.

Inflorescence

The arrangement of flowers on a plant, showing diversity in structure and adaptation.

Floral Primordium

The early stage of flower development after hormonal and structural changes are initiated in the plant.

Androecium

The whorl of stamens, representing the male reproductive organ in a flower.

Gynoecium

The female reproductive organ in a flower, consisting of pistils.

Stamen

The male reproductive part of a flower, consisting of a filament and an anther.

Anther

The terminal, usually bilobed structure of a stamen where pollen grains are produced.

Microsporangia

Four-sided structure in the anther consisting of four microsporangia located at the corners, two in each lobe

Pollen Sacs

Develop from the microsporangia, extend longitudinally through the anther, and are packed with pollen grains.

Tapetum

The innermost wall layer of the microsporangium that nourishes the developing pollen grains.

Sporogenous Tissue

Compactly arranged homogenous cells at the center of each microsporangium in a young anther.

Microspore Tetrads

Cluster of four cells formed by the meiotic divisions of the cells of the sporogenous tissue.

Microsporogenesis

The process of formation of microspores from a pollen mother cell (PMC) through meiosis.

Pollen Grain

Represents the male gametophytes in flowering plants.

Exine

The hard outer layer of a pollen grain, made up of sporopollenin.

Sporopollenin

One of the most resistant organic materials known, forming the exine of pollen grains.

Germ Pores

Apertures on the pollen grain exine where sporopollenin is absent.

Intine

The inner wall of the pollen grain, made up of cellulose and pectin.

Vegetative Cell

The larger cell in a pollen grain containing abundant food reserve and a large irregularly shaped nucleus.

Generative Cell

The small cell in a pollen grain that floats in the cytoplasm of the vegetative cell and divides to form the two male gametes.

Pistil

The female reproductive part of a flower, consisting of the stigma, style, and ovary.

Monocarpellary

Gynoecium consisting of a single pistil

Multicarpellary

Gynoecium having more than one pistil

Syncarpous

Pistils are fused together

Apocarpous

Pistils are free

Stigma

The part of the pistil that serves as a landing platform for pollen grains.

Style

The elongated, slender part beneath the stigma in the pistil.

Ovary

The basal, bulged part of the pistil containing the ovarian cavity.

Placenta

Located inside the ovarian cavity

Megasporangia

Arising from the placenta, commonly called ovules.

Ovule

A small structure attached to the placenta by means of a stalk called funicle.

Funicle

The stalk by which an ovule is attached to the placenta.

Hilum

The junction between the ovule and funicle.

Integuments

One or two protective envelopes that encircle the nucellus of an ovule.

Micropyle

A small opening at the tip of the ovule where the integuments do not enclose the nucellus.

Chalaza

The basal part of the ovule, opposite the micropylar end.

Nucellus

A mass of cells enclosed within the integuments of an ovule, containing abundant reserve food materials.

Embryo Sac

Also known as the female gametophyte

Megasporogenesis

The process of formation of megaspores from the megaspore mother cell.

Megaspore Mother Cell (MMC)

A large cell containing dense cytoplasm and a prominent nucleus, which differentiates in the micropylar region of the nucellus.

Monosporic Development

Embryo sac formation from a single megaspore

Pollination

The transfer of pollen grains (shed from the anther) to the stigma of a pistil.

Autogamy

Pollination achieved within the same flower.

Chasmogamous Flowers

Flowers which are similar to flowers of other species with exposed anthers and stigma.

Cleistogamous Flowers

Flowers which do not open at all.

Geitonogamy

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

Xenogamy

The transfer of pollen grains from anther to the stigma of a different plant.

Hermaphrodite Flowers

Flowers containing both male and female reproductive organs.

Self-Incompatibility

A genetic mechanism that prevents self-pollen from fertilizing the ovules.

Pollen-Pistil Interaction

recognition followed by promotion or inhibition of the pollen

Emasculation

Removal of anthers from the flower bud before the anther dehisces using a pair of forceps

Bagging

Emasculated flowers have to be covered with a bag of suitable size, generally made up of butter paper, to prevent contamination of its stigma with unwanted pollen

Double Fertilisation

Two types of fusions, syngamy and triple fusion take place in an embryo sac

Syngamy

Fusion of one of the male gametes moves towards the egg cell and fuses with its nucleus

Triple Fusion

The other male gamete moves towards the two polar nuclei located in the central cell and fuses with them to produce a triploid primary endosperm nucleus (PEN)

Parthenocarpic fruits

Fruits develop without fertilisation

Apomixis

Production of seeds without fertilisation

Polyembryony

Occurrence of more than one embryo in a seed