Flashcards For NEET Biology Sexual Reproduction in Flowering Plants

Stamen – made up of anther and filament

Provides nourishment to pollen grains

Homogenous tissue present in the microsporangia of a young anther

Each cell is capable of developing into microspore mother cell

Microspores develop into pollen grains

Made up of sporopollenin, the most resistant organic compound known

Germpore- does not contain sporopollenin

Made up of cellulose and pectin

Has irregular nucleus

Divides mitotically forming two male gametes

Pistil – made up of stigma, style and ovary

Syncarpous- pistils fused, e.g. Papaver

Apocarpous- pistils free, e.g. Michelia

Present in the ovary, attached to placenta

One ovule – wheat, mango, paddy

Many ovules – watermelon, papaya, orchids

Encloses nucellus except at micropyle

Pollen tube enters through this pore

Antipodal cells are present at the chalazal end

Only one cell at the micropylar end differentiates into the megaspore mother cell

Only one of the four megaspores develop into female gametophyte, rest three degenerate

Egg apparatus – 3 cells at the micropylar end, 2 synergids and 1 egg cell.

Antipodals – 3 cells at the chalazal end

Central cell- 2 polar nuclei

Cleistogamous – flowers which do not open

E.g. Oxalis, Viola, Commelina

Water – Vallisneria, Hydrilla, Zostera (seagrasses)

Wind – grasses

Moth – Yucca, moth lays eggs in the ovary

Triple fusion – formation of a triploid primary endosperm nucleus by fusion of the second male gamete and two polar nuclei

Triploid

Coconut water and tender coconut – free-nuclear endosperm

E.g. black pepper, beet

Can be induced by growth hormone application

Seedless fruits

E.g. banana

Production of seed without fertilisation

Embryo is formed without fertilisation from diploid egg cell

E.g. Asteraceae, grasses

Formation of multiple embryos in a seed. All the plants are genetically identical

E.g. Mango, Citrus