Tag: seeds - structure and germination

Vivipary is the phenomenon of germination of seeds inside the fruit while it is still attached to the parent tree. Such adaptation is found in halophytes. Viviparous plants produce seeds that germinate before they detach from the parent. In many mangroves, for instance, the seedling germinates and grows under its own energy while still attached to its parent.

Coleoptile is the pointed protective sheath covering the emerging shoot in monocotyledons such as grasses. Coleoptiles have two vascular bundles, one on either side. Coleoptiles consist of very similar cells that are all specialised to fast stretch growth. They do not divide, but increase in size as they accumulate more water. Coleoptiles also have water vessels along the axis to provide a water supply. 
Thus, the correct answer is option C.

Vivipary has two different meanings. In animals, it means development of the embryo inside the body of the mother, eventually leading to live birth, as opposed to laying eggs. In plants, it means reproduction via embryos, such as buds, that develop from the outset without interruption, as opposed to germinating externally from a seed. Examples: Cocos, Squash, Rhizophora. It is because all these seeds have high moisture content.

The first domesticated crops include eight plant species with three cereals, four pulses and flax. These are namely Triticum dicoccum, T. monococcum, Hordeum vulgare, lentils, pea, chick pea and bitter vetch. Thus, out of the given options, barley and wheat the one of the oldest cultivated crop of world. 
Thus, the correct answer is option D.

The germination process which takes place below the ground and the cotyledon and endosperm do not come out of the soil is called as Hypogeal germination.

In many dicotyledons like beans, castor, and some monocotyledons, the cotyledon is pushed above the soil by rapid elongation of the hypocotyl and they function as photosynthetic organs till the establishment of the seedling. This kind of germination is known as epigeal germination. 

The mangroves grow as a group of shrubs along the tidal coasts of mudflats, with specially evolved viviparous (bringing forth live young)  seed development just like mammals. In mangroves, Abscisic acid(ABA) a plant hormone plays a significant role in viviparous germination of seeds. 

Stigma feathery or papillote. Silken threads of Maize are very long stigmas but some authors regard them as long styles bearing equally long stigmas inthe apical region.