Tag: seeds - structure and germination

Long filamentous threads protruding at the end of a young cob of maize are styles. The apex of the stem ends in the tassel, an inflorescence of male flowers. When the tassel is mature and conditions are suitably warm and dry, anthers on the tassel dehisce and release pollen. Maize pollen is anemophilous and because of its large settling velocity, most pollen falls within a few meters of the tassel. Elongated stigmas, called as silks, emerge from the whorl of husk leaves at the end of the ear. They are often pale yellow and  like tufts of hair in appearance.
At the end of each is a carpel, which may develop into a kernel if fertilized by a pollen grain. The pericarp of the fruit is fused with the seed coat referred to as caryopsis, typical of the grasses and the entire kernel is often referred to as the seed. The cob is close to a multiple fruit in structure, except that the individual fruits never fuse into a single mass. 
Thus, the correct answer is option B.

Seeds of flowering plants are either dicotyledonous or monocotyledonous. While, the dicotyledons are characterized by two kidney shaped cotyledons, these are either non-endospermic exalbumnous or endospermic depending on the presence of endosperm and food storage areas. The monocotyledons with a single cotyledons are also differentiated as endospermic and non-endospermic based on the presence of endosperms. In case of Alisma and orchids, the seeds are extremely small with an undifferentiated embryo that lacks endosperm. They are referred to as acotyledons or exceptional monocots.
Thus, the correct answer is option C.

Monocot seeds are mostly endospermic, but Alisma is a monocot non -endospermic seed. In most monocotyledons the seeds are endospermic. The embryo is embedded in the endosperm which the seedling will use upon germination. In few they are non-endospermic seeds like that of dicotylednous plants where the endosperm is absorbed by the embryo as the latter grows within the developing seed and the cotyledons of the embryo become filled with stored food. 
Therefore, the correct answer is option C.

Cocos nucifera, the coconut palm, is a monocot perennial member of the Arecaceae, cultivated in tropical areas worldwide for its fruit and fiber. Coir, the fiber from the husk of the coconut is used in ropes, mats, door mats, brushes, sacks, caulking for boats, and as stuffing fiber for mattresses. It is used in horticulture in potting compost, especially in orchid mix. Thus, option A is correct. Corchorus, Clematis and Crotalaria are dicot plants. Thus, other options are wrong.

Sunflower is an oil seed plant (Helianthus annus L). The seeds of sunflower has 39 to 49% of oil.  It is the premium cooking oil because it has high level of unsaturated fatty acids. 

In monocot seeds, the radicle is enclosed in a protective sheath called the coleorhiza, while the plumule is enclosed in a sheath called the coleoptile.

The 'bird of paradise flower', or 'crane flower' as it is sometimes known, was first introduced into Britain in 1773 by Sir Joseph Banks. The plant itself can reach up to 5 feet in height with a 2-3 foot spread. The plant is trunk less, compact and clustering but slow growing with fleshy roots. S. reginae has banana shaped stiff- leathery, concave, oblong, bluish-gray leaves with a pale or red midrib. The leaves are attached to a long stalk that sometimes reaches up to 2 feet in length.