Plant Reproduction: Double Fertilization and Embryo Development

Flashcards covering the key concepts of double fertilization, endosperm development, and embryogenesis in angiosperms.

Significance of Double Fertilization

A unique feature of angiosperms ensuring the parent plant invests a seed with a food store only if the egg is fertilized.

Zygote Development

The diploid zygote develops into an embryo, which develops into a new plant.

Double Fertilization

A complex fertilization mechanism in flowering (angiospermic) plants, discovered by Nawaschin in liliaceous plants like Lilium and Fritillaria.

Porogamy

Entry of the pollen tube into the ovule through the micropyle.

Chalazogamy

Entry of the pollen tube into the ovule through the chalaza.

Mesogamy

Entry of the pollen tube into the ovule by piercing the integuments.

Siphonogamy

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

Syngamy

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

Triple Fusion

Fusion of a second haploid male gamete with a diploid secondary nucleus, producing a primary endosperm nucleus (PEN) that develops into a triploid endosperm.

Development of Endosperm

The triploid primary endosperm nucleus repeatedly divides mitotically to form nutritive tissue.

Nuclear Type Endosperm

Endosperm development where the primary endosperm nucleus repeatedly divides mitotically without wall formation, producing a large number of free nuclei.

Cellular Type Endosperm

Endosperm development where the division of the triploid primary endospermic nucleus is immediately followed by wall formation, resulting in a cellular endosperm from the beginning.

Helobial Type Endosperm

Endosperm development occurring in Helobiales, where the first division of the primary endosperm nucleus is followed by a transverse wall, dividing the cell unequally.

Mosaic Endosperm

Endosperm containing tissues of two different types, forming a mosaic pattern.

Embryogenesis

The process of development of the zygote into an embryo.

Suspensor Initial Cell

The larger cell towards the micropyle in the two-celled proembryo.

Embryonal Initial Cell

The smaller cell towards the chalaza in the two-celled proembryo.

Haustorium

The first cell of the suspensor towards the micropylar end that becomes swollen and functions as a haustorium.

Hypophysis

The lowermost cell of the suspensor.